In many families, the day a psychologist announces that a 7-year-old child is “gifted” feels like a turning point. We are already imagining an extraordinary educational path, facilities that will last a lifetime, sometimes specific arrangements at school. However, a large follow-up study shows that this fixed image does not really match reality.
What tracking IQ reveals through adolescence
Thousands of children and adolescents were tested repeatedly as part of the Twins Early Development Study (TEDS) in the United Kingdom, the results of this study were published in the journal
Intelligence & Cognitive Abilities. The authors distinguished two groups based on tests carried out at 7 years old: 3,958 children with so-called “normative” scores (between 99 and 115 points) and 1,580 children above 115, considered to be of high ability. The same participants were then assessed at ages 12, 16 and 21, then their trajectories were modeled using latent curve models. “We sought to shed light on the question of whether it is reliable to identify children with high cognitive ability at premature stages of development. Given that the measures exhibit relatively low reliability at early ages, we expected remarkable cognitive/intellectual changes throughout childhood and early adolescence“, indicate the researchers.
The results confirm this strong mobility. Among children in the high ability group at age 7, only 16% maintain a high level at age 16. In the normative group, around 8% of “average” children at age 7 reach a high level at age 16. The scientific study describes a population “cognitively mobile” where some of the children lose their lead, while a small minority, from average scores, climb to the top of the distribution.
On this basis, researchers believe that identifying “giftedness” very early on is therefore of limited interest. According to them, the age when it really becomes relevant to talk about high general ability is around 12 years old, provided that regular reassessments are organized. Concretely, a child who is gifted at 7 years old can return to normal a few years later, while a previously discreet friend can see his performance improve during middle school.
Genes: a powerful driver of cognitive evolution
To explain individual trajectories, the researchers integrated genetic markers into the statistical model. Their observation is clear: “Polygenic (genetic potential) scores rather than situational factors such as home and school environments (behavior problems, home chaos, life events, etc.) predict identified changes in cognitive ability as children grow“. They add: “This pattern is especially true for children with high cognitive ability“.
School: a decisive lever in adolescence
The study data show that school engagement at age 16 accompanies an increase in cognitive abilities, regardless of the starting level. The authors are not talking here about “academic success” in the administrative sense, but about the real involvement of the student in their learning.
This means that a stimulating school environment can help some adolescents progress well after the end of primary school, including those who were not classified as high ability at age 7.
According to them, “Linking genetic potential, brain development and cognitive ability is crucial to better understand the identified changes“.
The environment: a less determining factor than we think
The study also reveals a notable difference between children depending on their initial level. Researchers show that:
- Children with normative scores at age 7 are more sensitive to family instability and life events;
- Highly gifted children seem relatively protected from these environmental variations.
They write that family or school factors do not predict cognitive trajectories as strongly as genetic markers. The authors conclude that “premature identification of children with high cognitive ability is not justified“and that”scheduled follow-ups are necessary because we have found that most children are intellectually mobile as they age. Among those who obtained a score one standard deviation above the mean at age 7, only a tiny minority subsequently preserved their high ability marks“.
Even if this study reinforces the idea of a more genetic origin of intelligence, it does not make it possible to resolve the innate-acquired debate which has opposed many scientists for decades. However, it allows us to put into perspective the importance of IQ tests at early ages, showing that this assessment of intelligence can give results which will vary greatly over the course of life.