Research into the environmental and genetic foundations of expert performance has attracted attention across several domains of skill, reflecting the applied and scientific implications of this topic. Superior performance is a desirable achievement across domains; those who acquire expertise are esteemed and act as role models for others. Research on expertise also has the potential to inform organizations and industries that rely upon the acquisition of exceptionally high levels of skill by developing evidence-based training protocols and assessment tools. Furthermore, the study of superior performance can tell us about the role of experience and training in brain plasticity, which has implications for our understanding of learning and cognitive transfer. For example, we have the potential to understand whether engaging in specific forms of skills training (e.g., learning a musical instrument) may yield cognitive and physical benefits that extend beyond the domain of training. Finally, by examining individual differences in the acquisition of superior performance— including variables such as personality, physical traits, intelligence, motivation, and social environment—we can elucidate the developmental antecedents of elite levels of performance, and the role of genetic predispositions and gene-environment interactions. It has long been known that expert performance runs in families (e.g., Galton, 1869), but until relatively recently it has been difficult to tease apart the environmental and genetic factors responsible for this tendency.