Place but not Date of Birth Influences the Development and Emergence of Athletic Talent in American Football

The purpose of this study was to examine the birthplace and relative age effects in National Football League (NFL) players. The place and date of birth of NFL players in the United States were analyzed with Monte Carlo simulations to determine if either factor was predictive of the probability of reaching the elite level in this sport. Consistent with previous findings on professional North American athletes in baseball, ice hockey, basketball, and golf, players born in cities with populations of less than 500,000 were significantly over-represented in the NFL, whereas players born in cities with populations over 500,000 were significantly under-represented. Unlike many other sports, no relative age effects were found for the NFL. Small cities, in particular, appeared to possess characteristics that facilitate the development and/or emergence of athletic talent in American football. Possible psychosocial factors mediating the birthplace effect are discussed as are implications for the development of sporting expertise.

Birthplace Effects on the Development of Female Athletic Talent

This study examined the extent to which an athlete's place of birth can influence the likelihood of playing professional sport. Information regarding the birthplace of all American female athletes in the Ladies Professional Golf Association and Women's United Soccer Association was gathered from official league websites. Monte Carlo simulations were used to determine if the birthplace of these professional athletes differed in any systematic way from official census population distributions. Odds-ratios were determined for cities within specific population ranges to ascertain if the likelihood of playing professional sport was influenced in any systematic way by city size. The analyses revealed that female professional soccer players born in cities of less than 1,000,000 were over-represented, as were female professional golfers born in cities of less than 250,000. Results are consistent with those of male professional athletes in suggesting that areas of lower population provide conditions more conducive to the development of expertise than do larger city environments.