Genetic and Environmental Constraints on Variability in Sport Performance

Why do some athletes benefit more than others from training and practice? A frequent observation of interindividual variation in response to training and practice raises important theoretical and practical questions about the nature of genetic and environmental constraints on skill acquisition and performance. This problem is a manifestation of the long-standing debate of nature versus nurture, which argues the precise proportion of performance variation in a population accounted for by genetic characteristics or environmental influences. The relationship between genetic and environmental constraints on responses to practice and training is complex, requiring a careful interpretation of the data in the extant literature and a comprehensive theoretical model to explain research findings. In this chapter, the theories of practice emphasizing the role of environmental constraints in explaining variability in expertise are evaluated, and the evidence favoring the role of genetic constraints in variability of interindividual responsiveness to training and practice is examined. The biological determinism underlying some recent interpretations of the roles of genetic diversity and environmental context on variation in human motor performance is rejected for an interactive model that is captured well by dynamic systems theory. The challenges for future research on the interacting constraints of genetics and environment are (1) to locate the primary and secondary influences on performance and (2) to understand the dimensions of their interactions in order to improve practical intervention programs such as those dedicated to talent identification and development.