CID: The journey of a lifetime

by the creators of

The journey of a lifetime

contents

18

Preface

Marcel Levi

09 23 29

Interviews

Background

06 Puzzle pieces Chantal Kemner on the many facets of child development research.

10 Metadata Otto Lange sets up a CID search engine.

16 Two views Eveline Crone and Hilleke Hulshoff Pol give their views.

12 Car wash Dienke Bos on the data factory known as YOUth. With surprising insights from Roy Hessels.

24 Nature vs nurture Susan Branje on the interaction between genes and environment.

20 Reaching out Ties Fakkel, Karlijn Hermans, and Sarah Durston take their research to the streets.

30 Babbling away Sita ter Haar looks for similarities between babies and birds.

26 Overarching Research transcends generations, explain Tina Kretschmer, Elsje van Bergen, and Sanne Geeraerts.

32 Grey area Jana Runze and Irene Pappa explain how genes influence behaviour.

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BRAM BELLONI

BOB BRONSHOFF

BRAM BELLONI

The Dutch Consortium on Individual Development brings together the best researchers in this field and has been conducting important research on developing brains in children and adolescents over the past ten years with support from the first NWO Gravitation Grant. In the process, many new and relevant knowledge has been developed in this field, which is reported in this special issue of New Scientist. The articles make it evident that with all this new knowledge about how young brains grow, work, learn, develop, and adapt, we understand more and more about human thinking, behaviour, emotion, social interaction, and much more. It is great and inspiring to see how close collaboration between different researchers from different disciplines has led to such a successful scientific result.

I hope everyone enjoys this fantastic tour of the developing brain.

06

BRAM BELLONI

Brain development in children is one of the most intriguing and fascinating topics in human biology and psychology, and gets to the heart of who we are and the route we take to get there. There is a growing understanding of how complex interactions between genetics, parenting, interaction with other children, and many more environmental factors affect child brain development. We increasingly understand what developing brains in children look like and how they respond to external stimuli, both positive and negative, and which neural pathways and processes are important in learning, emotions, behaviour, and many other things in which the brain plays a crucial role.

ABOUT THIS PUBLICATION: This special was created by the editors of New Scientist on behalf of the Consortium on Individual Development (CID), at the conclusion of ten years of the NWO Gravitation Programme.

Consortium on Individual Development Utrecht University, University Medical Centre Utrecht, Leiden University, Erasmus Medical Centre, University Medical Centre Groningen, University of Amsterdam, VU University Amsterdam Cohorts YOUth, RADAR, L-CID, Generation R, TRAILS, Project AWeSome, NTR

20

MAX KNEEFEL

by the creators of

The journey of a lifetime Radar

Universiteit Utrecht

PEPIJN BARNARD

COVER DESIGN: PASCAL TIEMAN

Final editing on behalf of CID Tess Beking, Marije Witsenboer Editor-in-chief Jim Jansen Coordination Eline Kraaijenvanger Final editing Stan van Pelt Contributors to this issue Bram Belloni, Bob Bronshoff, Fenna van der Grient, Peter de Jong, Maaike Putman, Dorine Schenk, Nikki Smolders, Silvijn Stokman, Pascal Tieman, Bruno van Wayenburg, Mieke Zijlmans Basic design Sanna Terpstra (Twin Media bv) Design Donna van Kessel (Twin Media bv) CONTACT NEW SCIENTIST Email redactie@newscientist.nl (for press releases), info@newscientist.nl (for editorial questions only), klantenservice@newscientist.nl Tel +31(0)85- 6202600 Address (post and street address) Oostenburgervoorstraat 166, 1018 MR Amsterdam Brand manager Thijs van der Post (thijs@newscientist.nl) Marketing & Sales Alex Sieval (alex@newscientist.nl) CONTACT CID Website www.individualdevelopment.nl Printing Senefelder Misset Doetinchem B.V. ISSN 2214-7403 The publisher is not liable for damages as a result of printing and typesetting errors.

Focus 04 Up close Sonja de Zwarte looks at prenatal brain development in 3D. 18 Infographic What studies are part of the CID? And what have they managed to achieve in the past ten years?

More...

09 Animal testing The number of laboratory animals could be reduced, argues Valeria Bonapersona.

29 Rejection hurts Social cues are important early in life, Michelle Achterberg explains.

14 Worldly science A glimpse into the life of Syrian PhD student Hekmat Alrouh.

34 Culture lab CID scientists and their research in the media. New Scientist reviews.

23 Identity Andrik Becht searches for the answer to the big question: who am I?

COPYRIGHT Absolutely nothing in this publication may be copied or stored in a database or retrieval system in any way without the written permission of the publisher. The logo and other trademarks of New Scientist are the property of New Scientist Ltd. The publisher has endeavoured to fulfil all legal requirements relating to the copyright of the illustrations. Anyone who is of the opinion that other copyright regulations apply, may apply to the publisher.

Also check out the kids special

25 Hand in hand Jeroen Mulder explains why statistics are both difficult and necessary.

Special CID | New Scientist | 3

UP CLOSE

Brain development in 3D Sonja de Zwarte (1986) is a postdoc at the Utrecht YOUth study.

‘I study prenatal brain development. We look at how the brain develops before birth and what factors influence it. After birth, we examine how this prenatal brain development affects children’s behaviour.

Today, we can do a 3D ultrasound of the fetal brain as early as during pregnancy. This means we are no longer looking at a flat image of the brain but can see different brain structures from multiple angles.

We can also calculate brain volume, for example. This way, we can keep a close eye on brain development during pregnancy.

We used to do this kind of brain research by hand; my predecessors and I got stuck on that too. It was very labour-intensive to visualise each individual brain. Thanks to great advances in artificial intelligence, we can now analyse a 3D ultrasound within seconds. I mainly work with deep learning, a part of artificial intelligence where computers are able to learn new things based on large amounts of data.

This allows us to measure brain development fully automatically over time, which means we can conduct research on a much larger scale.

2,800 pregnant women and their partners signed up for this study.

We performed 3D ultrasounds around the 20th and 30th weeks of pregnancy, and then we examined the babies around five and ten months after birth. When the children are three and six years old, they will visit us again and we will check their socio-emotional development.

MAAIKE PUTMAN

Pregnancy and the first years of life are very important for a child’s development. By the way, we study normal development, so people are not selected because they are sick or super healthy. For this research, everyone in Utrecht and its surroundings was approached in order to get as much of a cross-section of society as possible. The beauty of such a comprehensive study is that we also know a lot about the parents, the pregnancy and birth, and the environment in which a child is growing up. Because we have so much data, we can investigate which of the many factors influence development in many different children. In the future, this offers opportunities to optimize individual development.

I recently received a grant to start my own line of research. Working with other partners, I will develop new deep learning techniques to extract even more valuable information about behavioural brain development from ultrasounds, MRI scans, and videos. We also want to see how these images can predict children’s mental health.’

Text: Jim Jansen

interview

Wanting to know how people become the way they are

Psychologist Chantal Kemner is scientific director of the ­Consortium on Individual Development. For the past decade, she and her colleagues have been committed to collecting all the ­important puzzle pieces of child development.

Text: Eline Kraaijenvanger and Jim Jansen Photos: Bob Bronshoff

‘L

ong-term studies are the particle accelerator of the social sciences’ – it is a statement that captures the imagination. This apt comparison saw the light of day in 2012, when psychologist Chantal Kemner and six colleagues stood before a review committee with their proposal: a Dutch consortium for child development research. Although the plan had to take shape in a short period of time and, in this composition, the group had only spoken to each other online, the mood after the interview was almost ­euphoric. ‘It went extremely well,’ says Chantal. ‘We really felt like it might actually work out.’

That feeling proved to be justified: as one of six teams, they received a grant of no less than 28 million euros from the Netherlands Organisation for Scientific Research (Nederlandse organisatie voor Wetenschappelijk Onderzoek or NWO), a so-called Gravitation grant for excellent research. It was the start of the Consortium on Individual Development (CID), with Chantal at the helm. The objective?

To find out why some children do better in life than others. Now – more than a decade later – dozens of researchers in five cities are collaborating in six major long-term studies. These so-called cohorts are essential for unravelling the complex process of child development.

The Netherlands ranks fifth among the happiest countries in the world. So, why is it that not every child flourishes?

‘That is exactly what we are so keen to

explore within the CID. Every parent wants their child to grow up healthy and happy, yet this is not always the case. I think we often do not realise how super complex child development is – perhaps because we see them growing up all around us. It is a complex interplay of many factors, which also change over time. Within the CID, the focus is on the development of social competence and behavioural control. You need these two skills to get along in society. If they do not develop properly, a person may experience all kinds of problems later in life. How people behave as adults is largely determined by how they develop as children.’

What makes the consortium special?

‘Within our field, there is a lot of individuality; everyone specialises in their own ­subject. This is almost inescapable when the subject matter is so complex. But that does make it difficult to combine or compare all the individual results. And that is precisely what is so important. With the CID, we brought together researchers from many different research traditions, and ensured that the data needed to work together became available. Not only data from behavioural studies, but also information from biological research, animal studies, and mathematical models. I think that is where our strength really lies: all these different studies, research groups, and measurement tools complementing each other in trying to unravel this complex issue. With a particle accelerator, physicists study the building blocks of the universe. With the cohorts – our own ­particle accelerator – we explore the building blocks of our inner world.’

Why is child development so complex?

‘Simply put, child development is determined by two things: genes and environment. Your genes determine the biological building plan, such as how your brain forms. At birth, the baby brain contains almost as many nerve cells as there are stars in the Milky Way. And then there are ten times more supporting cells in the brain. All these different cells also make all kinds of connections with each other... It is an incredibly large and complex network.’

And that is just the brain. How does the ­environment fit into that picture?

‘The environment in which a child grows up has a huge impact on their development. You can imagine how many different factors play a role in this: how parents interact with their child, where the child lives and what they eat, whether they have siblings, what friends they have, whether they experience stress... Everything has an effect on how the brain develops, which in turn determines how a child behaves. To study the role of all these ­different influences, you need information on large groups of children. And that information is in our cohorts.’

A major advantage of cohorts is that they follow children over a long period of time, from baby to young adult. Why is that so important?

‘Within the CID, we want to know how people become the way they are. This – as mentioned above – has everything to do with how you are born and how you grow up. Importantly, all these processes change over time: a newborn baby is not yet socially adept, nor can they control themselves. That takes many years. So, it is Special CID | New Scientist | 7

interview

CV

‘Now we have the information of thousands of children; that is such a different playing field.’

Smiling, she adds: ‘That is far from easy.

Babies may look very cute in an EEG cap, but you cannot give them clear instructions. And adolescents really do have more exciting things to do than lie in an MRI scanner. But overall, fortunately, our ­participants really enjoy taking part in our studies. We depend on them; without them, the research simply stops.’

All these different studies are bound to produce huge amounts of data.

Chantal Kemner (1964) is professor of biological developmental psychology at Utrecht University. She is the scientific director of the CID and heads the Utrecht YOUth study. She studied biological psychology and spent years researching the processing of faces in children with autism. However, she says: ‘It became increasingly clear that to understand autism, we first need to understand how social skills develop in general.’ So, she made the switch to researching the baby brain.

impossible to fully understand child development if you only measure at one point in time. With our studies, we try to capture all these processes that have an impact at different points in life and see how they affect the development of social competence and behavioural control. As such, we hope to identify all the important puzzle pieces of child development.’

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‘Absolutely. When I was doing research myself, I was used to doing studies with small groups of subjects: if you had a hundred children, that was already a big study.

But now we have information of thousands of children; that is such a different playing field. This allows us to explore both the big and the very specific questions, or just look at the technical aspects of our research methods. For example, within the CID, we sometimes work with an eye tracker, an instrument that measures eye movements.

As it turns out, children with blue eyes produce more inaccurate data than those with brown eyes (see page 13, ed.). Such subtle differences may sound rather boring, but they do affect how we interpret our data. That is now coming to light with our ‘particle accelerator’ and I think that is fantastic.’

On 31 October 2023, the NWO Gravitation grant will expire. Looking back on the past 10 years, of what are you especially proud?

‘I am incredibly proud of how we found each other – the CID has really brought us together. It enabled us to define theoretical frameworks together, to formulate research questions, and to really collaborate with each other. And because 2012 was the first year that the Gravitation grants were available and there was little experience of this kind of large partnership, we really did pioneering work. It was not always easy, but it has proved incredibly valuable and is something of which I am very proud. The enthusiasm and eagerness with which our researchers listen to each other and exchange knowledge is great to behold.’

Where do you hope child development research will lead in the next decade?

‘Researching child development is a lengthy process, as is the development itself. And what I have realised is that 10 years is actually very short. The CID has been a first big, important step and it is now up to us and others to build on it.

And although the CID is ending, that does not mean that what we have built together disappears. Anything but: CID scientists have already formed new consortia and received grants to continue their research. We can also draw on that vast collection of information for a long time to come. We are currently recording it in a gigantic archive (see page 10, ed.). This will allow scientists to continue researching perhaps the most complicated question in science for years to come: how do we become who we are?’

YOUNG TALENT

Valeria Bonapersona: ‘Do not let other people set your limits for you.’

‘I have always been interested in stress and the relationship between the body and the brain. It probably started when I wrote a biology paper on this as a teenager. For me, to study stress basically means to study what life is. It is about how we, as human beings, respond to our environment – it is truly ­fascinating.

As a stress researcher, you cannot get away from doing animal studies, but I slowly came to realise that I hate doing animal testing with my whole heart.

Halfway through my PhD research at the CID, I began to wonder: we have been researching stress for so long now, is it really necessary to do all these experiments? Or can I gather that information in other ways? 99.9% of all the research that we do now has already been done in the past; new studies are hardly ever disconnected from earlier ones. Yet in practice, we rarely use data from prior research to improve our own current research.

I consider myself lucky that, from a young age, I knew what I enjoyed and what my talents are. I have my parents to thank for that. They have always ­supported my ideas and taught me to not let other people set my limits for me. This attitude makes me creative and aware of every opportunity that presents itself. It is up to you to grab it.’

Text: Eline Kraaijenvanger Special CID | New Scientist | 9

BRAM BELLONI

Based on that idea, we developed the online RePAIR tool (Reduction by Prior Animal Informed Research, ed.) for scientists. We then showed that this tool can indeed reduce the number of laboratory animals by using information from previous studies in analyses.

This research was published in Nature Neuroscience in 2021; I am extremely proud of that – especially of everything it represents: close collaborations, the support of my professor, and that the message of being critical about animal research and how we do it, came from a biologist.

Decades of data No science without data. Data specialist Otto Lange ensures that the collected research data can also be found by ­other scientists.

Text: Peter de Jong

T

he six cohorts of the CID have collected a huge amount of data over the past decades. One of the objectives of the CID is that these data can be interconnected and that other scientists can benefit from it.

It is up to the team of the Connecting Data in Child Development (CD2) ­project to provide insight into this treasure trove.

It is a hell of a job – because how do you bring ­order to decades of data? And how do you then build a system where everyone is able to extract the data out of the CID treasure trove? The magic word: metadata. Speaking is Otto Lange (1965), technical coordinator of CD2.

10 | New Scientist | Special CID

How should we picture such a huge ­search engine?

‘Our online search engine allows interested scientists to search the databases of the six CID cohorts. The first step was to map out all the data collected by hundreds of researchers over the years. It is often hugely ­varied. Each discipline uses its own specialist terms, and the data is sometimes known under different headings. So, it was quite a job. This was followed by consultations on the so-called metadata – the data that makes up our search catalogue. In the end, the CD2 project took more than three years and described the developmental data of 186,400 children.’

Metadata? What exactly is that?

‘Metadata are descriptions of data. Data ­includes questionnaires, IQ scores, videos,

brain scans, and DNA material. Metadata are the characteristics of that data, e.g. by whom was it collected, and as part of which study? It may also include background information about the participants or the device and settings used for measurement. So, basically it is data about data.

This is important information that you want to know as a scientist if you want to reuse other people’s data. It also describes under what other terms this data is known; this is particularly important if you want to look up data.’

Can you give an example?

‘Suppose a behavioural scientist from ­Groningen is researching the social ­well-being of adolescents from Groningen ­during the Covid-19 pandemic and is looking for comparison material in the rest of

of my head – find a link to down-hearted adolescents in the RADAR study or to resilient adolescents in the Generation R project. To retrieve the actual data, she will then have to turn to the data managers of ­RADAR and Generation R.’ Is that not cumbersome?

He laughs: ‘At the moment, yes. In the ­future, we hope to link this to data release portals, so that the actual data can be ­accessed directly via our search engine.

YOUth and L-CID are already hard at work on this, so it is coming. The first important step is being able to find the data in the first place, followed by releasing that data.

What makes the latter more difficult is that it involves children’s sensitive data. Perish the thought that hackers, for whatever ­reason, might get hold of child data. All possible risks must be eliminated.’

MAAIKE PUTMAN

What are the next steps?

Otto Lange

‘The amount of ­available scientific data ­ has ­exploded’

the Netherlands. To direct her to the right studies where she can find that data, we use harmonised search terms – metadata, in other words. This means that, in agreement with the scientists who collected the data, we use the same set of terms about child development for all cohorts. There has to be agreement on what we include under mental health: not just depression or anxiety disorder, but perhaps also happiness, resilience, you name it. This will allow the researcher to see the related data collected in the different cohorts. She can then still filter on all sorts of aspects, such as age of the participants or year in which the data was collected – useful if, for example, you only want data from adolescents during the pandemic.

In the search engine, the researcher from Groningen will probably – this is off the top

‘To make CID data available as much as possible, we are linking our catalogue to ODISSEI, the national social sciences data platform. This contains much more metadata, including data from Statistics Netherlands. This presents great opportunities for researchers. Other metadata systems around the world, such as the European CESSDA, will soon be able to retrieve our metadata. There are a lot of developments in this area at the moment, allowing us to learn from each other and to keep growing as a network.’

You have worked in computing since the beginning of the computer age. What is the current situation in terms of the amount of available scientific data?

‘It has exploded. The only question is to what extent it is used. There is room for ­i­mprovement, is my impression. By nature, many researchers are primarily focused on their own research and often tend to collect new data themselves, which is a shame, because there might already be something you can benefit from. If you want to know something about the social effects of lockdowns on children, it is good to know that useful data was already collected d ­ uring the pandemic. Together you can do more than alone, you just have to know how to find each other.’

Special CID | New Scientist | 11

Dienke Bos

Brain to Byte Text: Bruno van Wayenburg Photos: Bram Belloni

A

nyone entering YOUth does not immediately think: ‘This is a real data factory’. There are long tables where parents sit with their children, there is a toy crocodile, and on the walls are photos of hundreds of children.

It is more reminiscent of a day-care centre than a scientific institution producing gigabytes of useful research data.

But in fact, that is exactly what it is, says ­Dienke Bos (1985) – executive director of the YOUth study, based in a cluster of outbuildings at the University Medical Centre Utrecht (UMCU). This large-scale cohort was set up a decade ago by the CID and studies the psychological, social, and neurobiological development of Dutch youth, from pregnancy to adolescence.

Children that participate in the YOUth study go through an entire car wash, says Dienke Bos

Data factory ‘We have followed a total of 4,200 children,’ says Dienke. ‘There are two main cohorts: young children from pregnancy to seven years and a teen cohort up to 16 years.’ As such, we do not have to wait years for the outcomes.

The scale of the project is exceptional, and unique for Europe. ‘The trend is to ­s­tudy larger and larger groups, to get more detail and more statistical power,’ says Dienke. This is important because child development is a complex interplay of many factors; sometimes the effects are very subtle. You can only visualise them if you have a large dataset at your disposal.

But this data factory is not just about ­collecting as much data as possible. All the supporting processes are also important, from setting up the factory properly beforehand, to publishing the collected data afterwards. At the YOUth study, this was set 12 | New Scientist | Special CID

up with foresight and almost military precision.

Car wash The emphasis in the YOUth study is on social development and the development of impulse control: how do children interact with others and how do they learn to control themselves? In recent decades, this knowledge about early brain development has advanced by leaps and bounds. But this type of research is not without effort: for YOUth, a team of 40 employees is constantly busy – finding parents with children to participate, scheduling, hosting, supervising, and making sure the various research stations operate seamlessly. ‘The children go through an entire car wash,’ says Dienke.

For example, there is the room with the ‘fake’ MRI scanner. There, children can get used to taking images of the brain in a real MRI scanner. Dienke: ‘The real one is somewhere else in the UMCU, but it is only available for brief periods of time, and we have only one chance.’ An old MRI scanner allows the children to practise lying still in a rather cramped tunnel.

Dienke: ‘That includes some active teenagers, so it can be tricky.’

We then enter the eye tracking room, where the children watch videos while an eye tracker registers what they are looking at. When babies experience something unexpected, they look at it longer. This enables researchers to deduce things about what babies remember or recognise.

In the EEG room, children are given caps

Roy Hessels

With the ‘fake’ MRI scanner, children can get used to the narrow space and the loud noises.

insight

Eye for detail

T with electrodes, and electrical activity in the brain is recorded. ‘Look at these, how funny,’ says Dienke, pointing to the smallest EEG cap.

And then there is a room that only has cameras and directional microphones around a rug with toys on it. ‘This is where we film the interaction between parents and their children,’ says Dienke. ‘One of the most time-consuming jobs is coding the recordings: writing out what is said and done from moment to moment.’

Long-term thinking Only this encrypted information may be released, unconnected to the subject’s name. Dienke: ‘The privacy measures are strict: researchers who want to work with the data go through a rigorous procedure.’

Interest in the collected YOUth data is plentiful: ‘The researchers who helped set it up were given priority, and have also already published their results,’ says Dienke, ‘but there are currently many requests for the use of this data, also from foreign researchers.’

With the data, scientists can answer ­various questions, some even unforeseen.

Unexpectedly, for example, the study has provided an opportunity to track the social development of babies during and after the Covid-19 pandemic. Dienke: ‘What are the effects on development, and are those ­effects long-term or short-term? We can study that very well now.’

hat the smallest – and seemingly unimportant – details can affect your research, university lecturer Roy Hessels (1990) knows all too well. He specialises in eye tracking – measuring what someone is looking at. For the YOUth study, he tests these measurement tools, and trains researchers in their use.

Eye trackers are getting better, cheaper, and easier to use. But using them correctly with children or babies remains quite a task, Roy knows: ‘In experimental psychology, we are used to adult subjects who you can instruct, and who can sit still. Things are a little different with a baby of a few months. In that case, it is especially important to do things slowly, but even then it does not always work out.’ Because the child is restless, for example, or because of technical problems, or – usually – because of a combination of the two.

Take, for example, the effect of eye colour. An eye tracker consists of a camera pointed at the eye along with an infrared light. ‘This produces a reflection,’ Roy explains. ‘The moment the eye moves, the pupil in the image shifts.

The reflection also shifts, but slightly less than the pupil, because the eye is not perfectly spherical.’ Based on where pupil and reflection are relative to each other, the eye tracker software can figure out where the eye is focused.

‘But this often does not work as well with a light eye colour, such as blue eyes,’ Roy noted: ‘In infrared, blue eyes actually have a dark colour, and so the pupil is harder to distinguish from the iris.’ In other words, blue eyes ­provide less accurate data than brown eyes. This can affect the way you ­interpret the data.

In a small group of participants, this subtle effect would have been lost in that of other factors that also play a role. As a result of that, you might wrongly conclude that blue-eyed children are less able to concentrate than browneyed children. Roy: ‘We have recently started using an eye tracker for babies that is much less sensitive to this.’

Text: Bruno van Wayenburg

Research with an eye tracker can be quite a challenge with babies.

IVAR PEL

Special CID | New Scientist | 13

Photo report

‘The red pencil I used to vote for the first time is still in my bag’ Text: Mieke Zijlmans Photos: Hekmat Alrouh

Pandemic ‘I study the influence of genetics on behaviour with data from the Netherlands Twin ­Register (NTR). I am currently studying how obesity is passed down between generations within one family, i.e., from parents to children. I am also researching whether obesity is related to people’s education. Earlier, I looked at the effect of the pandemic on obesity and child well-being. This includes psychological symptoms such as depression and anxiety, as well as their expression, including arguing and aggression.

During the pandemic, I did online research on the effect of the pandemic on children with psychiatric problems. In normal circumstances, you could never study something like that – you cannot put vulnerable children in isolation to see what it does to them. B ­ ecause of the lockdown, we were now able to study this.

And because NTR had been ­collecting data for decades before the pandemic, we are now also able to compare it with well-being during the pandemic and after.’

Political refugee ‘I came to the Netherlands as a political ­refugee in 2018, from Qatar. I was told to

leave the country within ten days. If I did not go of my own accord, the police would put me on a plane to Syria, where I was born. ­Since I had been on holiday in the Netherlands a few times, I came here. I took a hotel room in Amsterdam, walked to a police ­s­tation, and told them I wanted to apply for asylum. That is possible, the police said, you can apply in Ter Apel.

I ended up spending about ten days at the ­application centre. After that, I stayed in recreational park Duinrell and finally in Friesland.

After seven months, my asylum application was approved. During that period, I took an

During the ODISSEI-SICSS workshop

In the Dubai desert

Poster presentation at the 2022 ECSR conference with Paulina Pankowska

14 | New Scientist | Special CID

With my PhD supervisor Meike Bartels

With the red pencil

CV

Enterprising ‘In February 2024, I hope to receive my PhD. I do not know yet what I will do after that. ­Maybe get a job as a postdoc at the university. But I might go off in a completely different direction.

With my dog Odin

intensive Dutch language course. Once I received my refugee status, I immediately applied to the VU Amsterdam. Fortunately, I was hired.’

Passport ‘I have now settled down in Amsterdam. I live with my girlfriend in a small flat, with two cats and a dog. I don’t work on weekends.

Cooking is my passion – I enjoy trying dishes from all cuisines from around the world.

What makes sense to me is allowing scientists to do research with information from companies like Google, Facebook, and Instagram. This information is currently not permitted by law to be used, for privacy reasons, but if the data is properly anonymised – and if individuals give their consent, of course – then you could use it for scientific research. It would be a huge source of information.

In addition to science, I have always been interested in entrepreneurship. It is fun to come up with practical solutions to social problems. For example, just after I came to the Netherlands, I set up a start-up called

Physician-scientist Hekmat Alrouh (1986) was born in Syria and grew up in Dubai. He studied medicine in Qatar, but had to leave the country. He ended up in the Netherlands, where a grant allowed him to start as a researcher at VU ­University Amsterdam. Successfully so, as he is now doing his PhD research at the CID on the influence of genes and environment on health.

‘CrowdMuse’ with two friends. The idea is to create an online system in which designers can develop promising fashion projects, which they then co-own. That is completely different from working for a boss from whom you receive a salary.’

I feel at home in the Netherlands, because I can be myself. I am allowed to speak my mind and I can do the work I want. At the end of 2023, I will have been in the Netherlands for five years, then I can apply for a passport.

I only have a Syrian passport; in Qatar, I was given no more than a temporary residence permit. You will always remain a Syrian there, no matter how long you live there.

Last year, I voted for the first time in my life, in the Amsterdam municipal elections. That was an important moment for me. For the first time, my voice mattered. I kept the red pencil with which I was allowed to vote – it’s still in my bag.’

With Sofieke Kevenaar, a CID colleague

Special CID | New Scientist | 15

Optimal development Text: Mieke Zijlmans Photos: Bram Belloni

Developmental psychologist Eveline Crone discovered that the brain is sensitive to rewards. These include physical rewards for yourself, like winning money, but also social ones, like when you do ­something good for others.

We are studying whether personal and ­positive parenting advice to parents has an effect on their children’s development. Using brain research, we then look, for example, at how the brain responds to r­ ejection or reward. But the results in themselves do not say everything, so we put them alongside those of other methods. This gives us an overall picture.’

Eveline Crone (1975) studies the adoles-

What are your main findings so far?

cent brain. She states that the notoriously awkward stage of puberty is essential in a person’s development. She is head of the L-CID study in Leiden.

‘We found that adolescent brains respond

What does your research involve?

‘I study how young people can grow up in the best possible way; how their social worlds, such as parents, school, and friends, interact. My staff and I pay attention to a person’s environment and personal characteristics. We are particularly interested in how it is possible that people are sometimes focused on the well-being of others and at other times on their own well-being. How do you balance between these interests? We take into account all kinds of influences from the environment, such as the neighbourhood in which the child grows up, the role of the family, and that of friends. Together, these social worlds influence who the child is.’

How do you research that?

‘Using brain research, questionnaires, and, recently, youth and teacher panels. We ­deliberately combine different research methods; none is perfect.

At the L-CID, we are following five hundred families with twins for several years.

16 | New Scientist | Special CID

Eveline Crone

strongly to rewards. This can lead, for example, to experimenting with alcohol and drugs. But it can also lead to social ­behaviour, because working together also releases a pleasant feeling in your brain.

An interesting new twist in our research is that you can categorise behavioural patterns into profiles, combinations of behavioural traits. For example, people who are empathetic on the one hand, but who are good at standing up for themselves on the other. By the way, there is not necessarily

Hilleke Hulshoff Pol

one optimal profile. All these people, falling under all these different profiles, are needed to form a good society.’

Ideally, what do you want to achieve?

‘I want to find out what young people need to discover their own talents and find their way in the complexity of today’s society.

The aim is to make sure young people are not pigeonholed into a single category.’

What do you do when you are not working?

‘With me, private life and work are completely intertwined. I do not really have a good work-life balance, so to speak. I enjoy doing fun things with my husband and children.

But I also like taking them to work events, and I enjoy working with nice people.’

Ideally, neuroscientist Hilleke Hulshoff Pol would like to give everyone a chance to develop to their full potential. She ­explores how the growth and shrinkage of our brains are related to this.

Hilleke Hulshoff Pol (1962) works in

brain research. At the YOUth study in ­Utrecht, she uses MRI scans to study how brains change throughout life.

What does your research involve?

‘I study how brains grow and shrink throughout life. Our brains continue to evolve throughout our lives, constantly adapting to new environments and life stages. It is fascinating that we can now see in an individual how connections in the brain develop over time, and how these connections are affected by genes or experiences.’

How do you research that?

‘We ask children to come in for an MRI scan of their brain every three years. This approach with repeated measurements has since been applied in several locations around the world, but in the Netherlands, we were pioneers. We have already been able to collect the data of more than three thousand children in the YOUth study, even from babies before birth, in their ­mothers’ wombs.

Worldwide, we and other researchers have measured the brains of over 15,000 people of all ages twice, so that’s over 30,000 scans. It is fantastic what you can achieve when you work together. Among other things, we looked at brain development in childhood and adolescence.’

What are your main findings so far?

‘The biggest breakthrough of our research is that we have proved that genes affect brain growth or shrinkage. We also have evidence that these changes affect how we function, how we develop, how we

age, and possibly the development of ­psychiatric disorders.’

Ideally, what do you want to achieve with your research?

‘What you would like is to give everyone the opportunity to develop to their full potential, taking into account their own unique combination of genes, environment, and experience. My research in itself cannot be d ­ irectly ­applied to, for example, diagnosis of disorders; that requires a much broader approach. But it does contribute to ­discovering the mechanisms behind ­certain conditions.’

What do you do when you are not working?

‘I like to spend time with my husband and my two adult children. And I love walking the dog. And actually... actually, I would like to make time to sculpt, like I have done in the past. I am very visually inclined and find it fascinating to shape things three-­ dimensionally.’

Special CID | New Scientist | 17

CID cohorten The Consortium on Individual Development (CID) unites the forces of six l­ arge-scale cohorts in the Netherlands that study children’s development over long p ­ eriods of time. TRAILS, NTR, Generation R, and RADAR have been following their p ­ articipants for decades and were able to study the next generation with the CID. The CID additionally set up two new cohorts a decade ago to fill the gaps in existing knowledge: YOUth and L-CID. Each cohort offers a unique contribution and together they form a treasure trove of knowledge. Nationwide, more than 186,400 children and their families are now participating in one of the CID cohorts.

Nederlands Tweelingen Register Vrije Universiteit Amsterdam

The Netherlands Twin Register (NTR) was formed in 1987. By investigating twins, one can study the extent to which differences between children can be attributed to genes or environment. NTR also researches DNA, questions parents and teachers, and looks at school results. At NTR, the main focus is on the contribution of hereditary predisposition to diseases and the development of behavioural problems.

L-CID

Universiteit Leiden In the L-CID study 500 families with samesex twins participate annually and parents receive parenting advice. This data will be used to study the development of children aged 3 to 14 years to find out why not all children are equally sensitive to variations in the social environment.

Generation R

Erasmus MC Rotterdam Generation R tracks the development of nearly 10,000 children in Rotterdam.

Children from almost all ethnic groups in the Netherlands are participating. These children are followed from early pregnancy until adolescence. There is increasing evidence of major differences in growth, development, and health between these groups. It is not yet known what factors influence these differences. That is exactly what Generation R aims to unravel.

18 | New Scientist | Special CID

INFOGRAPHIC: PEPIJN BARNARD

TRAILS

Rijksuniversiteit Groningen & UMC Groningen TRAILS is a long-term study of the psychological, social, and physical development of children and young adults. More than 2,500 participants are taking part, with examinations taking place every two to three years since the age of ten. During adolescence and young adulthood, young people make choices that can have a major impact on later well-being, behaviour, and health. More knowledge can help prevent or treat any problems at an early stage.

YOUth

Universiteit Utrecht & UMC Utrecht YOUth is a study that follows thousands of children from pregnancy to adulthood to study how they develop as they grow up. For example, what roles do upbringing, heredity, environment, and contact with peers play? And how does brain development enter into the equation? The result: a large dataset, which researchers can use, both now and and in the future, to answer all kinds of questions about child development.

RADAR

Universiteit Utrecht RADAR is a long-term study focusing on adolescents’ interactions and conflicts with parents and peers. The aim of RADAR is to identify both the normal and problematic development of young people. During adolescence, the risk of depression, anxiety, and anti-social behaviour increases. Around 800 young people are being studied. Unique to this study is that their parent(s), partner, sibling, and (best) friends also participate.

Special CID | New Scientist | 19

‘Outreach holds up a mirror to scientists’ Text: Peter de Jong Photos: Bram Belloni

Karlijn Hermans

S

cience is indispensable to society, there is no doubt about that. But how do we best convey this knowledge to society, in such a way that these discoveries have a wider reach than just academia? How do we unlock this treasure trove of scientific knowledge for a wide audience? And vice versa, how do we obtain data from society that is relevant to research?

Outreach – coming down from your ivory tower with your research – is the answer, also for the CID. Three CID researchers talk about how outreach features prominently in their work. As one plays ­football at FC Utrecht, another puts up a colour cross at Lowlands or has students chat with the mayor. ­

Behavioural scientist Karlijn Hermans (1990) knows her stuff when it comes to outreach. As part of the L-CID, she was not only involved in organising the ­E xpedition Next science festival, but she also initiated the Teacher Project, in which researchers and teachers work together closely.

‘The CID’s Teachers Project is the ultimate outreach. It is a new approach to research: we share our knowledge of children’s 20 | New Scientist | Special CID

social development with teachers, and we learn from their wealth of experience.

They know exactly what works in class.

Sarah Durston

Another project close to my heart is All Schools Collect (Alle Scholen Verzamelen), in which three thousand children from 76 primary schools took on the role of researchers. Students composed a top five of what they need to be social, such as more breaks or better listening. They then went on to survey adults about what they thought was important. A few children decided to interview none other than their mayor. One of them cheekily reported back to his teacher: ‘We were not able to discuss everything, the mayor is quite a chatterbox.’

Children are very creative in coming up with research questions and they keep you on your toes. For example, a little boy asked his teacher: ‘Why exactly are we participating in this study?’. In this way, children are playfully introduced to how science works, and the research connects to children’s social worlds. ­Citizen science in optima forma.

The most important thing about outreach is that, as scientists, we not only transmit our knowledge but also learn from stories from society. As far as I am concerned, ­science will become even more open and accessible.’ ­

Sarah Durston (1974) is professor of developmental brain disorders at UMC Utrecht. In collaboration with the CID, she set up #kletsbaar, a surprising project that has appeared at festivals across the Netherlands.

The Colour Cross made an appearance at Lowlands 2022.

‘My outreach project is called #kletsbaar (a portmanteau of ‘kletsen’, Dutch for chatting and ‘kwetsbaar’, or vulnerable, ed.) – chatting about vulnerability. We want to make people think about psychiatry. Psychiatry should not be abstract and remote, the person is not one with their illness, but someone like you and me, who experiences reality differently due to circumstances. It is something that can happen to all of us. Everyone is vulnerable.

MAX KNEEFEL

Part of my outreach is the Colour Cross (Kleurenkruis), a four-armed, five-coloured inflatable pillow you can climb into. We toured the country with this wobbly 9-by9-metre cross – we even went to Lowlands.

What you notice is that everyone who steps into the cross becomes disoriented. Inside, there are five different colour zones, the

sound is distorted, and you cannot see a clear horizon. Reality is momentarily called into question, as it is for someone with a psychiatric disorder. We then discuss psychiatry with the visitors. A total of 3,000 people entered the Colour Cross; 1,800 of them participated in a survey about their views on psychiatry.

Special CID | New Scientist | 21

outreach

As a researcher, Ties not only successfully establishes contact with the outside world, but also within the CID he managed to unite the forces of all research groups for a scientific paper on the under-representation of young people with low socio-economic status. Ties: ‘This project has contributed to the discussion around diversity and inclusivity across CID and beyond.’

Ties Fakkel

‘When you visit people’s homes, only then do you really know what is on their minds’ lation. Apparently, we are not successful in reaching these people. This is unfortunate, because it is precisely children growing up in more difficult circumstances that are of great value to our research, and vice versa.

I want to use outreach to make psychiatry more human; we need to get rid of the stigma often attached to labels. Take, for example, young people labelled with ADHD. They are told that their brains work differently. This makes them think: ‘Oh, my brain works differently, I’ll never get rid of that.’ But one-third of those with ADHD grow out of it during puberty. I recently heard from a 20-year-old diagnosed with ADHD that he had never learned to concentrate. After all, he was given Ritalin for that. That is what labels do. The CID is about vulnerability, but also about resilience. It is incredibly important that we continue to talk about this.’

22 | New Scientist | Special CID

Psychologist Ties Fakkel (1990) is a born storyteller. For instance, he made a vlog for the children in the YOUth study while walking, and recorded a spokenword performance about unequal opportunities. He studies the influence of parents’ socio-economic status on their children’s development.

‘I noticed that only ten per cent of the ­participants in my research have a lower socio-economic status, while this group constitutes one-third of the Dutch popu-

Together with colleagues, I set out to find this target group. We contacted schools, libraries, and community centres in working-class neighbourhoods. We also visited FC Utrecht, a real club of the people. The children who play there come from neighbourhoods all around Utrecht and are ethnically much more diverse than those in our study. We taught them playfully how active your brain is during football, for example with dribbling and free running.

It has not yet brought in many new recruits, but we have learned plenty. As researchers, we should go into neighbourhoods much more and make real contact with people.

So, no academic language or a complicated brochure, but a lot of listening to what matters to the people there. When you visit people’s homes, only then do you really know what is on their minds. Outreach is not just about connecting. It is also a mirror that shows the extent to which we scientists are connected to society.’

YOUNG TALENT

Andrik Becht: ‘Knowing who you are is a psychological source of resilience’ ‘The big identity question – who am I? – emerges in adolescence and develops into young adulthood.

You start to wonder who you want to become, what friends you want to surround yourself with, and what kind of career you want to pursue. Recurring doubts about your identity play a big role in how you feel. My PhD research at the CID showed that young people who displayed high levels of identity insecurity on a daily basis were more likely to experience anxiety and depressive feelings. Or, turning it around: knowing who you are is a psychological source of resilience.

I think the CID has allowed many young researchers to qualify as good scientists who can now start their own research. For example, I have since set up my own study on the development of ecological identity.

I have always been very attentive to nature – I am a major fan of pruning. But since having children, my interest in the environment has really been sparked.

It is truly great when you manage to link your personal passion to your professional life; that would have been impossible without the foundation the CID gave me. Good science is teamwork and I have been lucky to be part of the CID community.’

Text: Eline Kraaijenvanger Special CID | New Scientist | 23

BRAM BELLONI

The longer young people continue to explore these identity questions, the stronger that relationship with negative feelings becomes. This is not illogical – society simply expects you to make choices at some point. These expectations can cause stress. I quite understand that young people experience a lot of stress nowadays – they have to prove themselves in so many different areas, and all the while society is becoming more and more complex. Of course, there are individual differences in the way in which people deal with making choices: some see only hurdles, while others see four ways around them. But what matters most is how much you engage with these choices on a daily basis.

‘Parents are not always responsible for their child’s behaviour’ Text: Silvijn Stokman Photo: Bram Belloni

W

hen she was just a child herself, Susan Branje (1973) already knew she wanted to work in child development. She had soon made her choice: she would study developmental psychology in Nijmegen.

There, she obtained her PhD with honours in 2003, studying adolescent relationships.

Around that time, she also joined Utrecht University, where she currently leads the large-scale RADAR study. RADAR attempts to draw conclusions about the role of the environment in children’s growing up by collecting data on people over a long ­period of time. The focus here is on adolescence. Every day, this kind of research brings us a little closer to answering the age-old question: do we become who we are because of our genes, or our upbringing? Is it nature or nurture?

The RADAR study focuses on using ­­ so-called longitudinal data. What does that mean?

‘It involves following people over a longer period of time. A lot of research surveys a group of participants only once. They look at how parents are raising their children right now, or at a parent’s behaviour towards their child at that moment. Instead, we study whether parents are raising their children the same way they were raised, for example. You actually also want to know how things were with those parents in the past, and whether you see similar patterns in that, which we call transfer.’

24 | New Scientist | Special CID

Is it not easier to simply ask parents now how they were raised in the past?

‘When you question that retrospectively, people’s memories are coloured by their current experiences. For example, parents may want to be like their child, or mainly remember negative or positive things from the past. That is why longitudinal data is very important here, to see if there is transmission and when exactly it takes place.

Also, you simply need multiple measurement moments to measure a child’s entire development.

There are not many such long-term studies in the world, but in the Netherlands, there are a few at the CID. We are among the world’s leaders in that respect.’

Are there any drawbacks to this method?

‘In terms of content, there is not much to find fault with, because it does indeed ­provide a wealth of data. The drawbacks are mainly of a practical nature; it is difficult to sustain such large longitudinal data sets. In the Netherlands, social sciences – unlike the other sciences – do not have large long-term grants. So, you have to ensure funding over and over again. Unfortunately, this also makes it harder to keep participants involved in your studies. That is why you have to invest in maintaining a relationship with them.

When we started this research, our very first respondents were around 12 years old. Now, many of them have children of their own, who are also involved in the study. We are happy to have such loyal participants.’

What do participants do within the study?

‘We at RADAR mainly look at experiences, i.e., how people, their family members, and friends self-report about their relationships and behaviour, and how these are transmitted between generations. So, that is in the form of recurring questionnaires. But we also do home visits, for example, subjecting participants to tasks

Jeroen Mulder

column and making videos of parent-child interactions. We also collect genetic information from the respondents.’

What is the most striking thing that has come out of the research so far?

‘One of my PhD students looked at the transmission from parent to child of psychopathology, i.e., the extent to which ­people felt depressed or anxious. We see a clear correlation between how parent and child feel, but exactly how they influence each other is more complex than you might expect. Parental psychopathological symptoms are not only transmitted directly from parent to child, but children also influence their parents’ behaviour. This in turn contributes to the transmission of ­psychopathology. So, it is not a one-way process from parent to child, but rather seems to be a complex interplay in which they constantly influence each other.

For example, teenagers provoke many changes in the parent-child relationship.

So, in this, parents are not always directly responsible for their children’s behaviour; rather, they respond to their children. But by responding appropriately at the time, they can redirect teenagers’ behaviour.’

You have just got to the children of your first responders. Is it not a shame that the CID is coming to an end?

‘Yes, that is definitely a shame. We would like to have more time, for example, to merge all the data from multiple CID studies. Fortunately, most research projects will continue as usual. That also applies to the RADAR study – we have actually just started. There are still many measurements ahead and the coming years of our respondents’ lives are particularly interesting to follow in terms of development.

One of our goals is to answer the nature-nurture question. We still have a long way to go before we reach that point.

And yes, on the one hand, you try to give a clear answer to this question, but on the other hand, exposing its immense complexity is also important. It is becoming increasingly clear that it is both – nature and nurture. It remains a constant interaction.’

Statistically speaking

D

uring a statistics lecture on establishing cause-effect relationships, my lecturer came up with an example. It was in a 2010 article by Robert E. Larzelere, an American professor of Human Development & Family Science. He compared different methods for correcting problem behaviour in children: which approach can parents best use to reduce the unsocial or antisocial behaviour of their child? Professional interventions, such as using Ritalin or visiting a therapist? Or are parents better off addressing problem behaviour themselves, by sending the child to their room, yelling, or physically punishing them?

The lecturer showed a table of results. Four different statistical techniques were used to analyse the collected data: two techniques commonly used in sociology and econometrics, and two techniques that have a long tradition in psychological research. The same research question, the same data, but four different calculations to arrive at an answer.

The teacher started talking more and more enthusiastically. As it turned out, different analyses showed different results. Take snapping and shouting at your child, for example. According to one analysis technique, there was a positive correlation (more shouting and snapping leads to more problem behaviour), according to a second technique there was no correlation, and the last two techniques resulted in a negative correlation (more shouting and snapping leads to less problem behaviour). Professional interventions supposedly had no effect or actually led to more problem behaviour, depending on which analysis technique you used. And hitting your child could do no harm, according to two techniques.

The take-home message was clear: the interpretation of research results can depend on the analysis technique chosen, and the right technique is not always obvious. Especially in complex phenomena, such as children’s behaviour and development, statisticians and methodologists have an important role. Together with researchers, they look at what is the best design for a study, and what statistical techniques are needed to reach valid conclusions. Statisticians are also continuing to develop these analysis techniques so that researchers can answer new types of questions.

At the end of the lecture, I asked the lecturer which correction method she personally preferred. She left that question unanswered.

Jeroen Mulder (1994) is a PhD candidate in statistics at the CID. Want to know more? In the episode Statistiek met Jeroen Mulder from the Dutch podcast Makkelijk Praten, Jeroen explains why statistics are so difficult and interesting at the same time.

Special CID | New Scientist | 25

Sometimes the apple does fall far from the tree All good things come in threes, or so the proverb goes. That is certainly true in this case: three passionate scientists from three different studies are conducting research on third-generation participants.

Intergenerational research like this is essential to study the influence of genes and environment on behaviour.

Text: Dorine Schenk Photos: Bram Belloni

Is your own upbringing a good predictor of how you parent?

Does like father, like son also apply to parenting? In other words, does the way you were raised play a role in the way you raise your own children? The answer appears to be ambiguous. Some people are very similar to their own parents in the way they raise their children, while others are not.

Sanne Geeraerts (1988), researcher with the RADAR study in Utrecht, tries to explain these differences and bring this so-called intergenerational transmission of parenting into focus. It requires ­large datasets from long-term studies. That is why Sanne works on techniques and ways of combining existing studies.

‘In my research, I was initially interested in children’s behavioural control, i.e., the extent to which children can control themselves, control their emotions, and focus their attention on something,’ says Sanne.

26 | New Scientist | Special CID

­Sanne Geeraerts

‘This is related to all kinds of problematic behaviour.’ She focused mainly on children at first, but increasingly started to involve parents in her research as well.

Sanne shifted her focus to parenting and ended up with her current research. She looks at whether the way you were raised in the past predicts how you raise your children now. This requires long-term ­studies that map, on the one hand, how people were raised as children, and, on the other hand, how those same people raise their own children (often over 10 or 20 years later).

‘In Utrecht, we are studying this in the RADAR study,’ says Sanne. This study started in 2006 with nearly 700 teenagers.

Over three-quarters of the original participants, who are now around 30 years old, are still participating. Some now have chil-

dren of their own who also participate. As such, the ­study follows three generations.

But how do you measure parenting?

‘You can observe parenting, for example, in a laboratory setting or in people’s homes,’ Sanne explains. You set up a task, such as cleaning up toys, and watch how parents and children deal with it. That is a fairly objective way of measuring, but it is also a snapshot that is artificial and filmed.

At RADAR, researchers therefore also ask questions about parenting, to both parents and children. Sanne: ‘For example, we ask if parents raise their voices when their child disobeys.’

This provides interesting insights. For example, the researchers see a lot of variation between studies. In some, your own upbringing does seem to be a good predictor of how you parent and in others it is not.

Tina Kretschmer

‘Many people think that your own upbringing plays a big role in how you raise your children,’ says Sanne. ‘But what we have learned so far is that that relationship is generally not that strong at all. We do not know where the majority of these differences come from yet.’

Initial analyses show that parenting in early childhood may be a more important predictor than parenting later on.

But studying this properly requires a ­large, diverse sample and they are scarce.

That is why Sanne is trying to combine smaller, existing datasets. This is not easy, because these different studies are each set up with its own purpose. It is already a big step forward that the CID allowed third-generation participants from different Dutch studies to be measured in the same way. But ideally, you would like even more data, for example, from international studies as well.

‘I think that, in psychology, we can benefit a lot from techniques that combine existing datasets. Particularly developmental psychologists, as they often follow people for longer periods of time. These are expensive and time-consuming studies. Combining existing studies can help. I think there is a huge added value there.’

Sanne is now working in the United States for a year, at a research group with extensive experience in analytical methods to combine datasets from different studies. ‘Moreover, they have several longterm studies here with data that I can start combining with those of the RADAR study, among others.’

Does being bullied affect how you raise your children?

If you are badly bullied as a child or adolescent, how does that affect social relationships later in life, such as friendships? Does it make you less likely to trust people? Or do you enter relationships faster because you are happy that someone finally wants to spend time with you? Tina ­Kretschmer (1980) is trying to find answers to these questions within the TRAILS study in Groningen. For a few years now, she has also

‘Parents who have been bullied, might transfer these experiences to their children.’ been looking at whether social experiences, such as bullying, get passed on to the next generation. ‘I think parents who have been bullied in the past pass on that experience to their children through protection or parenting behaviour.’

‘A few years ago, I had a conversation with a colleague about my research,’ says Tina. ‘I said that I wondered to what extent being bullied as a child or adolescent affects how you raise your own children.

She told me that she was bullied badly and that now, when her four-year-old daughter goes to play at a friend’s house, she always makes her husband pick her up. She was unable to herself. She could not handle the possibility that her daughter would not fit in well in the group and she might be ­bullied as well.’

Five years ago, Tina received a grant to study whether being bullied affects the next generation. This project is part of the TRAILS study. Every few years, researchers collect information about the participants, in the form of interviews, questionnaires, tests, and sometimes physical measurements. Family members, school environ-

ment, and, in some cases, partners also provide information.

‘The TRAILS data is unique,’ says Tina.

Thanks to the use of various research methods, much is known about the parenting and social development that the participants experienced over the past 20 years. Their experience of bullying was also documented in detail, by not only asking the children themselves if they bully or have been bullied, but the whole class. That, combined with genetic information from participants and their parents, makes it an enormously rich dataset.

The dataset provides a picture of the bullying history of the participants, who are now in their early 30s. To study its impact on the next generation, information is needed from TRAILS Next, a project that has been running since 2015 and ­follows the children of TRAILS participants. By now, there are several hundred of them. Tina: ‘It starts with a diary study during pregnancy, where future parents write down, for example, whether they feel anxious or happy. Once the child is born, a researcher will visit 3, 30, and 54 months after birth for interviews and measurements.’

When the child is 4.5 years old, they will also be asked questions. Because children at that age cannot yet fill in a questionnaire, the researcher uses hand puppets, Tina says. ‘One doll says, for example: I have lots of friends. The other says: I have Special CID | New Scientist | 27

Elsje van Bergen

‘DNA is not going to change, but you can optimise a child's environment’ no friends. And then they ask the child: and you? So, we collect data similar to questionnaire data.’

In late January, Tina was awarded another grant. ‘With that, we can continue the study and gather information when the participants are in their mid-thirties. We will look, for example, at whether there is a difference in social development between people with and without children. I am excited about this, because we hardly have any data on adult social development.’

Tina and her colleagues will also continue to collect data from the participants’ children. ‘I think that, in the coming years, we will learn a lot about how being bullied carries over into the next generation.’

Is dyslexia in the genes or does it come from the environment?

On average, children of highly educated parents score higher on the final placement exams in year 8 of primary school.

‘But you cannot conclude from that that this is only because of the parenting and homework support that they owe to their parents,’ says Elsje van Bergen (1981), researcher at the NTR in Amsterdam. ‘Parents not only provide their children with an environment, but they also pass on 28 | New Scientist | Special CID

their genes.’ Elsje studies which environmental factors, such as parenting, affect children’s school performance. To distinguish these factors from the influence of genes, she also maps genetics.

As soon as Elsje discovered the world of science as a first-year student, she knew she wanted to become a scientist. With her broad interests, it was just a question of which field she would choose. After a flopped PhD in human movement science – ‘my supervisor, the research, and I were not a match’ – her perseverance led her to educational sciences at the University of Amsterdam. There, she did her PhD on research into children who are at an increased risk of dyslexia because one of their parents has it.

‘I became interested in why children with relatives with dyslexia are themselves at increased risk of this. Is it in the genes or does it come from the environment?’ says Elsje. That question led, via a few years as a scientist in Oxford, to the interdisciplinary research she does now. This focuses on the influence of genes and environment on differences between children in school skills, such as reading and maths.

It brings together three disciplines: educational sciences, psychology, and behavioural genetics, i.e. the interplay of genes and environment in behaviour.

This research into cause and effect is not straightforward. ‘We know, for example,

that children who are read to and have many books at home do better in school on average,’ Elsje says. ‘But you do not know if this is actually causal.’ It is also true that parents with dyslexia often enjoy reading less and have fewer books in the house. So, their children not only grow up with fewer books, but also with a genetic risk of dyslexia. ‘If such a child has dyslexia, you do not know whether it is due to the home environment, where there are few books, or due to their genes.’

Elsje studies the influence of environment and genes with, among others, data from the NTR. She looks at family ties, for example. Identical twins are known to share almost 100 per cent of DNA and fraternal twins 50 per cent, as do siblings and parents and children. ‘So, you can look at adult identical twins – they both have the same DNA – where one of the two has a child,’ Elsje explains. ‘If the child is as similar to the mother as to the aunt in terms of, for example, numeracy, then it is passed on through the genes. If the child is more similar to the mother in this, then the environment she provided also has an influence.’

In addition, scientists are also looking directly at DNA, for example, by looking at what part of their DNA parents pass on to their child. ‘We look to see if the untransmitted DNA predicts placement exam ­scores, because then it must be an environmental effect.’

Elsje: ‘From research where we looked at the placement exam scores of identical and fraternal twins, we know that 75 per cent of the differences between children come from genetic differences and about 25 per cent from environmental differences.’

Last year, Elsje received a grant with which she will study what factors in the home environment influence those differences in learning performance. She will do this through genetic research, questionnaires for both parents and teachers, and with online language and maths games that allow researchers to see how much children are practising and learning.

By discerning which genetic and which environmental factors cause educational disadvantages, Elsje hopes to understand ways to reduce opportunity inequality in education. ‘DNA is not going to change, but you can optimise environment.’

YOUNG TALENT

Michelle Achterberg: ‘We should not underestimate the child brain’ ‘My research within L-CID looks at how children cope with social rejection. We have developed a new MRI task where children were accepted or rejected based on their personal profile. We based the profile on a friendship book they had to fill in.

They then came to the lab, and we explained: ‘We showed your profile to other kids. During this game in the MRI scanner, you will see what they think of your profile: ‘nice’, ‘I don’t know’ or ‘not nice’.’ These qualifications were purely fictional, but it allowed me to study social rejection in the brain, as well as aggression regulation. After the feedback, the children were allowed to play a feigned loud noise in the ears of their peers, as a way to vent.

We saw that there are certain networks in the brain that respond to both positive and negative feedback. These networks are already very similar to those of adults. There was, however, a difference in how the children handled their aggression after social rejection. This trait develops strongly between the ages of seven and ten – a very formative phase of life. We saw that the more the brain region responsible for behavioural control is developed, the better a person can control their aggression. This was the first study to demonstrate this, in almost 400 children; that is actually quite unique. It also proves that we really should not underestimate the child brain.

Outside my research, I am active in local politics and invest a lot of my time in science communication. This stems from a kind of rebellious impatience. I thought: we have so much data, why is nobody doing anything with it? So, I decided to do it myself. Every little bit helps and this way I can pass on my knowledge.’

Text: Eline Kraaijenvanger Special CID | New Scientist | 29

BRAM BELLONI

This kind of long-term research is incredibly valuable but requires a lot of patience. You literally have to wait for children to grow up. That is why I am happy to have been involved with the CID for ten years now. All the success of this consortium is due to a lot of smart people putting their heads together in order to work together.

interview

From singing zebra finches to babbling babies

BRAM BELLONI

30 | New Scientist | Special CID

Children’s language development can falter for many reasons.­ Psychobiologist Sita ter Haar studies how to detect language ­development disorders at an early stage.

Text: Fenna van der Grient

W

hen children have a language development disorder, it is often not discovered until they are around three to four years old. This is a shame, argues Sita ter Haar (1982), a psychobiologist at Utrecht University. Ideally, you would intervene much earlier. That is why she is studying whether very early language development, the so-called babbling stage, can be predictive of how good children are at language later on.

Songbirds go through a similar babbling stage, and it is a lot easier to monitor them. That is why Sita is combining baby research with research on zebra finches.

Why are you looking specifically at the babbling stage?

‘In that period, the second half of the first year in humans, a lot happens in learning and producing sounds. So, that is when you want to know if something is going wrong. Then you can intervene and make sure children get professional help in time, for example from speech therapists.’

What factors influence language ­development at this early stage?

‘There are a lot of them. Risk factors for language development disorder include premature birth, poor sleep quality, and smoking during pregnancy. The environment that you grow up in also plays a role, for instance, the culture or socioeconomic status of the parents. This affects the quality of exposure to language: do you hear enough diverse language; do you have enough interaction with your parents? When you hear language mainly from a screen, for example, you pick up some of it, but much less than in real interactions.

I am also looking at the influence of sleep – right now only in birds. Sometimes the

brain does not behave as it should during sleep. This may have genetic causes, or something may have gone wrong in development. For example, some children have epileptic brain activity when they sleep. You do not notice anything in their behaviour, but impressions are not stored properly in their memory. This can sometimes lead to a language disorder. Again, it is important to recognise this early on, so you can treat it.’

What does researching zebra finches look like?

‘I try to keep that parallel to the baby research as much as possible so that I can make a direct comparison. Zebra finches are domesticated animals that live in groups, so you can very easily keep them in a lab. The advantage of that is that you can study them in a very controlled way, without bothering them too much. For example, you can monitor exposure to singing, or you can offer a particular song very precisely. You can also track development from day to day, where with babies we are already very happy with two measuring moments.’

How do you translate that to babies?

‘Songbirds have the same babbling stage that babies have. The sounds are obviously very different, and a song is different from our language. But that early stage of sound-learning is quite similar. Like babies, birds first listen to what is happening and then start practising. They start trying things out: what can I do with my beak? We can track

‘Like babies, birds listen first and then start trying things out: what can I do with my beak?’

from day to day what they do and when they can produce certain standard sounds.

In addition, we can study individual differences. We then look at whether we see similar development and differences in people.

I also look at the effect of disturbed sleep on song development. Zebra finches cope with this miraculously well, and it is something you just cannot manipulate in babies.

We combine this research with brain studies in humans, in collaboration with UMC Utrecht. There, they do a lot of research on sleep deprivation, including in premature babies. They saw that the connections in the brain, the white matter, were reduced in those babies. We will now see if the same is true for the birds.

Conversely, in songbird research, we can again learn a lot from the systematic, almost mathematical way in which linguists approach language and language rules.

With songbirds, it is usually more about watching what they do. I really enjoy that interaction.’

What makes the CID a good environment in which to conduct this research?

‘There are experts from all different research areas. In particular, we work a lot with developmental psychologists and other linguists within the project.

And I also use the YOUth database, which tracks lots of different measurements in children over long periods of time. It is truly unique. What is also special is that many studies include video recordings. They actually record them for a different purpose, for example, to study play behaviour, but I can use them to see how parents and children communicate. I can then lay this alongside song recordings of zebra finches.

After studying the predictive effect of the babbling stage on language development, we want to study, for example, how this development is influenced by socioeconomic status and brain development.

These are all things that these other people at the CID are working on and we can connect with. The CID is really a goldmine for follow-up research.’

Special CID | New Scientist | 31

‘The science that we practice is not black and white’ on human behaviour. They talk about it enthusiastically, in fluent Dutch.

What does your research entail exactly?

Irene: ‘We study how genes play a role in

CV

Irene Pappa (1985) studied biology and medicine in Athens.

In 2011, she came to Rotterdam for a PhD at Generation R and a specialisation in psychiatry.

Now she works three days a week as a child psychiatrist and two days as a postdoctoral researcher at L-CID in Leiden. In her spare time, Irene plays basketball and supports undocumented migrants.

Text: Peter de Jong Photos: Bob Bronshoff

F

or those who did not already know: the research world is international.

As is the CID. It brought PhD ­student Jana Runze from Germany and postdoc Irene Pappa from Greece together; they are doing important research together on the effect of genes 32 | New Scientist | Special CID

how parents and children interact. This can be done in many ways. For example, based on a large number of genes, we calculated three genetic scores for parents: for IQ, income, and education.

If a mother has a high genetic score for IQ, this means she possesses a combination of genes that are characteristic of people with a high IQ – although it does not automatically mean she has a high intelligence. We saw that the higher the parents scored on IQ, income, and education, the better they recognised signals from the child and then responded appropriately.’

Jana: ‘In addition, we looked at whether

such a connection also existed the other way round. So, whether those same genetic scores, but in the children, showed a ­correlation with their mother’s adequate response. This was, indeed, the case. It may be that the child’s genes influence the parents’ behaviour, rather than just the other way around.’

Does that mean that if both child and mother have a high genetic score on those three aspects, the child will be more successful in later life?

Irene: ‘No, it does not. We quantify the

a­ verage effect of heritability on certain behaviour and do so in a large group of

people. We always talk about statistical odds. How someone ultimately develops is and remains a complex interplay of heredity and environment.’

Jana: ‘Just look at children’s school perfor-

mance. Children who learn easily may have inherited that trait from their parents.

But if there is no reading or discussion at home, or if the environment shows little appreciation for their learning abilities, they are less likely to perform well at school. The science that we practice is not black and white. We are putting a piece in the big puzzle of how nature and nurture together determine child development.’

their traits and their genes. You can then compare and combine the two. Ultimately, a particular gene combination is assigned a value associated with, for example, intelligence, income, and education, as well as traits such as obesity or depression. Such correlations are always quite small, because other factors may play a role as well, for example, the effect of environment, parents, neighbourhood, and school.’

How did you set up your research?

How do you know that certain genes are important for intelligence, income, and education?

Irene: ‘Because a lot of research has been

done on large groups of people, on both

Jana: ‘In the Generation R study, we have a

group of about 1,500 people around Rotterdam; in the future, the Leiden participants of L-CID will be added. These are parents and children whose genetic values we have measured. We did behavioural research on them: we then looked at how child and parent reacted to each other – both in their homes and in a lab at the university. We were not present ourselves but studied the video afterwards. This allowed interactions to be as spontaneous as possible.

For example, we let the parents and ­children play games that required them to work together, like building a tower. In another task, a child had to sort beads, while the parent was allowed to watch a fun movie, which we knew the child would also like to see. The parent’s job was to nevertheless motivate the child to keep sorting the beads.’

Does a child growing up in a bad neighbourhood with problematic parents have a chance at making it to university?

CV

Jana Runze (1992) studied psychology at the University of Twente and behavioural sciences at Radboud University Nijmegen. This summer, she will receive her PhD from VU University Amsterdam, partly on her research within L-CID and the collaboration with Generation R. Jana plays volleyball, runs, and is committed to helping street dogs.

‘It may be that the child’s genes influence the parents’ behaviour, rather than just the other way around’

Irene: ‘Yes, they certainly can. Young chil-

dren depend mainly on what their environment has to offer – especially their parents.

Older children can determine their environment much more for themselves, for example through hobbies and friends. On top of that, someone who likes and easily learns new things is more likely to seek out new challenges and new environments.’

What value does genetic research have for the behavioural sciences?

Jana: ‘Pinpointing the causes of behaviour

is very complex. Child development is an

intricated interplay between genes and environment. We already know a lot about the effect of the environment. If a child does not meet expectations based on his or her aptitude, it is good to look at their environment. Are there problems at home, or are things not going well at school? The more genetic knowledge we have, the more we find out about how important it is to change something about their environment.’

Special CID | New Scientist | 33

Culturelab CID scientists and topics can also be found in bookshops and online. New Scientist reviews.

e-magazine

Is our brain a big mystery? Drawing on popular issues such as gender differences and musical talent, neuroscientist Lara Wierenga unravels some of the many secrets in Atlas van het brein (Atlas of the Brain).

Atlas van het brein Lara Wierenga

Corona handbook for young people

T

hat young people suffered considerably during the Covid-19 pandemic should no longer come as a ­surprise. In the Dutch online magazine Het jongerenbrein in de coronacrisis (The adolescent brain in the corona crisis), Rotterdam Erasmus University’s SYNC lab showcases numerous studies on the well-being of young people during the ­pandemic, and various scientists provide insights into ­opportunity inequality, brain development, and parent-child relationships.

What immediately stands out is the accessible way in which the magazine is designed. Colourful panels attract attention and are accompanied by graphs, timelines, and photos. There is no shortage of bar charts: at a glance, it becomes clear that young people, for example, rarely received help with their online home education. The approachable language also makes the magazine easy to understand.

ple aiming to give innovative perspectives and ideas a platform. As such, the magazine’s solution-oriented approach immediately takes shape.

– NS, New Scientist

Also notable is the highlighted YoungXperts working group – a think tank for young peo-

Het jongerenbrein in de coronacrisis Erasmus SYNC lab

podcast

Gender stereotypes on the rack

‘B Genderneutraal opgroeien of toch niet?

Jong Geleerd on Spotify

34 | New Scientist | Special CID

oys like football and girls like dolls’ – you cannot really say this these days. Yet this misconception is still a strong driver in society – more strongly than we often think. Because, however open-minded we consider ourselves, expectations are still dominated by stereotypical gender images.

Breaking these patterns is exactly the aim of youth researcher Joyce Endendijk and Tess Schoneveld, project manager at VHTO Expertise Centre for gender diversity in STEM, engineering, and IT. In the Dutch podcast Jong Geleerd (Learned Young), they explain how genes and parenting ­affect gender roles and g ­ ender typing.

The show requires quite a bit of attention due to its fast pace, but at no point does the abstract concept of gender become tough or inaccessible.

Armed with a hefty arsenal of scientific studies, Endendijk and Schoneveld turn the taboo into a topic of conversation that is even suitable for birthday parties.

– NS, New Scientist

programme

Blessing or curse?

Adolescents sometimes spend multiple hours a day online.

people aged 14-17 from all regions of the Netherlands are participating in this research project. As it turns out, for 90 per cent of adolescents, social media has no negative impact on their well-being. They do find it difficult to regulate their screen time. All those attention-seeking beeps are simply too tempting. Especially if you are supposed to be doing your homework...

PEXELS/ANDREA PIACQUADIO

I

nstagram, TikTok, Twitter, Snapchat, LinkedIn, Facebook… if you want, you can spend all day scrolling.

The number of social media platforms we can choose from today is quite overwhelming. And with that, the discussion whether social media are good or bad for young people flares up again. The pros and cons seem to be fairly equal. Yes, social media turn out to be good for ones creativity and

friendships, but at the same time, they also lower selfesteem.

Media professor Patti Valkenburg has been studying the influence of smartphones and social media use on the well-being of adolescents for years. In 2022 she appeared on Nieuwsuur to tell about the results of her research, Project AWeSOme (Adolescents, Well-being and Social Media). 480 young

Interesting for both young and old: ­where is the line between healthy entertainment and gaming addiction?

Behavioural scientist Margot Peeters and psychoscientist Renske Spijkerman explore the dangers and ­advantages of video games in this episode of the Dutch podcast Jong Geleerd (Learned Young).

Gezond gamegedrag aanleren Jong Geleerd on Spotify

Want to know more? You can watch the episode of Nieuwsuur or read the recent public report from Project AWeSOme. Patti also wrote a book: Schermgaande jeugd. − EK, New Scientist 15 years of the smart­ phone Nieuwsuur Public report Project ­AWeSOme

Spotted

Tackling the bully

B

ehavioural scientist Tina Kretschmer explains the ­genetic basis of popularity with this YouTube video, and how indispensable twin research is in unravelling it.

Does your DNA make you popular?

University of the ­Netherlands

Language FAQ

I

n the YouTube video Taalontwikkeling (Language development), psychoscientist Caroline Junge and humanities expert Anika van der Klis answer parents’ frequently asked language questions.

Taalontwikkeling Dynamics of Youth

Girlpower

T

he book Baanbreeksters (Trailblazers) by neuroscientist Marian Joëls puts 12 impressive women on their well-deserved pedestal.

Baanbreeksters Vrouwen over hun weg naar de top Special CID | New Scientist | 35