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.

Long-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.’

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.

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.’

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

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 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.’

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.
‘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. 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.’

The enthusiasm and eagerness with which our researchers listen to each other and exchange knowledge is great to behold.

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?’

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.

This article is part of a New Scientist special issue about the Consortium on Individual Development, that will appear in September 2023.

Text: Eline Kraaijenvanger and Jim Jansen
Photos: Bob Bronshoff