Nature,nurture and academic achievement: A twin study of teacher assessments of 7‐year‐olds

Background: Twin research has consistently shown substantial genetic influence on individual differences in cognitive ability; however, much less is known about the genetic and environmental aetiologies of school achievement. Aims: Our goal is to test the hypotheses that teacher‐assessed achievement in the early school years shows substantial genetic influence but only modest shared environmental influence when children are assessed by the same teachers and by different teachers. Sample: 1,189 monozygotic (MZ) and dizygotic (DZ) twin pairs born in 1994in England and Wales. Methods: Teachers evaluated academic achievement for 7‐year‐olds in Mathematics and English. Results were based on the twin method, which compares the similarity between identical and fraternal twins. Results: Suggested substantial genetic influence in that identical twins were almost twice as similar as fraternal twins when compared on teacher assessments for Mathematics, English and a total score. Conclusions: The results confirm prior research suggesting that teacher assessments of academic achievement are substantially influenced by genetics. This finding holds even when twins are assessed independently by different teachers.