Joseph Baker and Sean Horton The Big Idea Whether human development is a product of nature or nurture is one of the longest and most colourful debates in the history of ideas. More common today however is the growing belief that we evolve by way of the intertwining of both our biological and environmental influences. This review paper explores the impact of these interactions on human performance, and in particular, on acquiring and demonstrating sport expertise. The inherent complexity of interacting influences in the pursuit of sport expertise is…