Researchers may have finally settled the question of which matters more for a child's development, nature or nurture: and nature appears to be the winner, according to a study looking at GCSE scores.
Educational achievement has been shown in previous studies by King's College London to be heritable, so researchers explored how other traits besides intelligence can affect exam scores, and showed that these traits are influenced by genetics.
The team looked at the GCSE results of 13,306 twins under observation for the much larger UK Twins Early Development Study. Comparing the results of identical and non-identical twins, they found that identical twins were likely to have more similar results, and identified that this was down to their genetics rather than the environment.
All of the participants were measured for 83 different traits, which were grouped into nine broad areas that could affect performance in school, such as behavioural problems, confidence, well-being, personality and intelligence. While intelligence accounted for more of the 'GCSE heritability' than other areas, the other domains accounted for as much of the heritability as intelligence, the researchers explained.
Eva Krapohl, from the MRC Social, Genetic and Developmental Psychiatry Centre at KCL and joint first author of the study, said: 'What our study shows is that the heritability of educational achievement is much more than just intelligence – it is the combination of many traits which are all heritable to different extents.'
Each of the categories correlated significantly with the core GCSE subject scores, and these correlations appeared to be largely affected by genetics. The heritability of GCSE scores was shown to be 62 percent, with the individual categories under investigation scoring a 35 to 38 percent chance of being affected by heritability.
Kaili Rimfield, co-author of the study, stated that the implications of this research should not have an effect on education policy (see BioNews 727). 'Finding that educational achievement is heritable certainly does not mean that teachers, parents or schools aren't important,' he said.
While the researchers observed is a demonstrable link between intelligence and genetics, as shown in this study, other factors are as important to the development of a child. The notion of 'heritability' was also used as a population statistic and does not provide information at an individual level, the researchers said.
Krapohl explained: 'It is important to point out that heritability does not mean that anything is set in stone. It simply means that children differ in how easy and enjoyable they find learning and that much of these differences are influenced by genetics.