ABSTRACT
While factors such as genetics and practice are primary influences in producing sport expertise, resources and environmental characteristics have been identified as important secondary factors that can constrain the influence of primary factors (see Baker & Horton, 2004). Failure to address secondary factors, which are pertinent to the actual lives of expert performers, may decrease the ecological validity of sport expertise models (e.g., Bronfenbrenner, 2005). In this chapter we review two such secondary factors, namely relative age and birthplace. Research on both these topics highlights how they can constrain the process of expertise development, and both phenomena demonstrate that sport expertise, like other developmental outcomes, is the result of interactions between individuals and their developmental environments (e.g., Lerner, 2006).
