Children with low social status or behavioral problems often do worse at school. British researchers have now shown in two studies that the genes are also involved.
Hardly any other factor influences children’s school performance as much as socio-economic status, i.e., social and economic living conditions. The lower the status, the weaker the school education, at least on average. Researchers around the psychologist Robert Plomin from London’s King’s College have shown that this relationship is also influenced by genes (1).
A good school education usually also has an impact on later development, the probability of employment, financial security, and even health. So it’s no wonder that scientists want to understand why children’s performance is so different.
In recent years, twin studies have often shown that genes also play a role. However, the extent of the influence was unclear. That’s why Robert Plomin and colleagues focused on the genome of schoolchildren. They wanted to find out not only how great its impact on school performance is but also how it relates to the social status of children.
More than 3000 twins born between 1994 and 1996 in England and Wales participated in the study. The researchers received the marks of their GCSE (General Certificate of Secondary Education) test when the twins were about 16 years old, and, additionally, information about their parents’ profession and educational level. In addition, between the ages of two and 16, the children took several tests that allowed conclusions to be drawn about their intelligence.
In order to compare the genomes of children, the researchers used the genome-wide complex trait analysis (GCTA) method. With the help of this analysis, the relationship between individual gene variants (single nucleotide polymorphisms) and a specific trait — such as school performance — can be calculated. For their study, the researchers looked for hereditary factors in almost two million genomic SNP variants.
As expected, the scientists saw a link between school performance and socio-economic status. Both variables also correlated with the children’s intelligence. When the researchers looked at the data on the genome of the children, they found that about 50 percent of the relationship between status and performance can be explained by genes. However, only one-third of the genetic variants associated with social status and education is dependent on children’s intelligence, and two-thirds are independent from it.
The study fits with other research in twin research that suggests that children’s academic performance is linked to many other traits that are also influenced by genes, in addition to their intelligence. This includes personality, e.g. self-efficacy.
In another study of more than 2,000 twins, Plomin and scientists around Gary Lewis from the University of London also looked at how genetic factors, but also environmental influences, affect the relationship between mental health and school performance (2).
Children who were particularly anxious, displaying behavioral problems, were hyperactive at the age of four, or had problems with peers, had, on average, worse GCSE grades than children without these difficulties. The link between anxiety and problems with peers and school performance seems to come mainly from environmental influences that the twins share. In contrast, the connection between behavioral abnormalities and school performance could also be explained in the study by the genetic material. The correlation between hyperactivity and school performance was explained on the one hand by genes, but additionally by individual influences from the environment that only affected the individual.
The researchers believe that factors such as parental warmth and support are among the environmental influences that affect behavioral problems, problems with peers, or anxiety. They also suspect that genes that affect emotion regulation or impulsivity may play a role in behavioral abnormalities and hyperactivity. Further studies will have to show whether they are right.
This is part 14 of a series covering twin health provided by Paul Enck from the Tübingen University Hospital and science writer Nicole Simon. Further studies in twin research can be found at the TwinHealth website. Translation was done with the assistance of DeepL translator.
- Trzaskowski M, Harlaar N, Arden R, Krapohl E, Rimfeld K, McMillan A, Dale PS, Plomin R. Genetic influence on family socioeconomic status and children’s intelligence. Intelligence. 2014 Jan;42(100):83-88.
- Lewis GJ, Asbury K, Plomin R. Externalizing problems in childhood and adolescence predict subsequent educational achievement but for different genetic and environmental reasons. J Child Psychol Psychiatry. 2017 Mar;58(3):292-304. doi: 10.1111/jcpp.12655.
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