In this chapter, we discuss empirical evidence addressing the nature-nurture debate from two different perspectives: infant studies and behavioural genetics. Current evidence suggests that there are two cognitive systems for encoding numerical information, and perhaps core systems for geometry. However, questions remain about whether these systems are both present at birth and hence the degree of determinism and the mechanisms by which they connect to later mathematics are still far from established. Behavioural genetics studies offer a valuable way to assess the origin of individual differences in mathematical cognition and to discriminate between genetic and environmental contributions. We thus review relevant evidence on core quantitative knowledge, mathematical abilities and cross-domain relations from twin studies. We conclude by suggesting that while there is convincing evidence of nature’s general and specific role in mathematics, it is clear that environment plays a fundamental role too. The real question for the future is not whether mathematics has a natural core but how to optimise the interaction between nature and nurture so that differential domain-specific and domain-general predispositions can meet an ideal environment to blossom into competent mathematics
