Some people learn languages quickly. Is this talent in their genes? Researchers in the UK studied thousands of twins. They looked at the twins' foreign language grades at school. Genes explained about half of the differences between students.

But this number is about a group, not about one person. Also, only about one third of these genes were special to foreign languages. Your study time, your methods, and where you learn can still change your results.

Why do some students pick up languages faster than others? Twin studies offer one way to explore this question. Identical twins share almost all their genes, while non-identical twins share about half. If identical twins have more similar grades, genes probably play a role.

A British team analyzed the exam results of more than 6,000 pairs of 16-year-old twins. Genes explained roughly half of the differences in their foreign language grades. That genetic part can be split into three.

About one third was shared with general intelligence, and another third with first-language skills. Only the last third was specific to foreign languages. Heritability describes differences within a group in a particular society. It does not mean that half of your own ability is fixed at birth.

Twin studies offer a way to test whether some people simply have a "gift" for languages. Identical twins share nearly all their genes, while non-identical twins share about half, so if identical pairs are more alike, genes are probably involved. Plomin and colleagues analyzed data from a large British twin cohort and estimated that genes accounted for roughly half of the individual differences in school foreign language achievement.

Among more than 6,000 pairs taking national exams at 16, heritability ranged from 36 percent for German to between 53 and 62 percent for other languages. Only about a third of that genetic influence was unique to foreign languages. The rest overlapped with general intelligence and first-language achievement. Heritability is also a statistic about a population, and it shifts with context.

In a society where everyone receives similar instruction, genes will appear to matter more. Where learning opportunities vary widely, the environment will look more influential. The studies also relied on school grades and teacher ratings, which may partly reflect motivation and study habits. A heritability of 50 percent therefore tells us nothing about how far any one student can improve.