New research has revealed how genes can influence how well children do throughout their time at school.
The study, published in The Conversation, was undertaken by Kaili Rimfeld, a postdoctoral research associate at King's College London, and Margherita Malanchini, a postdoctoral fellow at the University of Texas in Austin.
Using a sample of over 6,000 pairs of twins who are part of the UK-representative Twins Early Development Study, the researchers analysed their test scores from primary school to the end of compulsory education.
“Our new research found that the twins’ educational achievement was remarkably stable: children who do well in primary school also tend to perform well in GCSE exams, taken at the end of compulsory education,” Rimfeld and Malanchini said.
“Using twins allows us to estimate the proportion of differences that can be explained by genetic factors. Identical twins share 100% of their genes, while non-identical twins share on average 50% of the genes that differ between people, just like other siblings.”
Rimfeld and Malanchini said that if identical twins are more alike on a particular trait than non-identical twins, such as school achievement, it can be inferred that it is influenced by their genes.
“We can then estimate the heritability of that trait – or the proportion of differences that are down to the differences in children’s DNA sequence,” they said.
“We looked at what factors influenced stability in educational achievement – when grades in a standardised test remain similar between primary and secondary school.”
Rimfeld and Malanchini found that about 70% of the stability in achievement is explained by genetic factors, while 25% is accounted for by the twins’ shared environment, such as growing up in the same family and attending the same school.
The remaining 5% was explained by their non-shared environment, such as different friends or different teachers.
When there was a change in educational achievement – where grades increased or dropped between primary and secondary school – Rimfeld and Malanchini found this was largely explained by those environmental factors that are not shared by twins.
“It’s reasonable to assume that this substantial influence of genes on the continuity of children’s achievement during their time at school can be explained by intelligence,” they said.
“Yet we found the influence of genes remained substantial – at 60% – even after accounting for intelligence, which was measured using several verbal and nonverbal tests taken by the twins over the course of childhood and adolescence.”
Implications for early intervention
According to Rimfeld and Malanchini, the findings should provide additional motivation to identify children in need of interventions as early as possible, as problems are likely to remain throughout the school years.
“In the future, polygenic score prediction and the prediction of environmental risks – such as exposure to certain neighbourhood, family, and school characteristics – might provide a tool to identify children with educational problems very early in life,” they said.
They could then be provided with individualised learning programs, Rimfeld and Malanchini added.
“For example, we could use DNA tests at birth to identify children at genetic risk for developing reading problems, and give them early intervention,” they said.
“As preventive interventions have greater chances of succeeding early in life, a great strength of polygenic scores is that they can predict at birth just as well as later in life, which could be of particular help for those children who are likely to struggle the most.”