In Outliers, Malcolm Gladwell (2008) contends that date of birth is relevant to the success of hockey and soccer players. Can that be true? As you ponder this, also consider the relevance of someone’s place of birth. Does the success of an athlete relate to the population size of the city that he or she was born in? For example, would you rather select an athlete who was born in February in a town of over 5,000,000 or an athlete born in September in a town of less then 500,000?
THE RESEARCH STUDY
To address just such a question, researchers collected the birthday and place of birth information of 2,144 National Football League (NFL) players. No significant relationship involving birthday was found. There was not, for instance, an excess of players born in June and very few players who were born in August. Previously, it was thought (e.g., Gladwell) that players born right before the age cutoff in youth leagues would have an advantage because they would be older than their peers. A league of 15 years olds could have one boy who is 15 years old and three days and another who is 15 years old and 364 days. Since older children tend to be more physically developed than younger children, the older children could have an advantage.
As to the other finding, place of birth did have an effect: a disproportionate number of players were from cities with populations of less than 500,000. The proportion of athletes from major cities with over 5,000,000 people was less than what would be expected if it is assumed that larger cities should have more players in the NFL than smaller cities. Imagine that there are two groups of people trying out for the NFL. One group consists of 50 people, and the other group consists of five people. It is expected that more people from the group of 50 will make the NFL than from the group of 5 because the group of 50 is larger. If 10% of people who try out for the NFL make it, then the larger group would have five people who make it, while the smaller group would have only one. That is what would be expected, and it is the opposite of what was found.
THE BOTTOM LINE
This relationship between place of birth and professional-athlete status has also been found in the sports of baseball, ice hockey, basketball, and golf. In speculating on the mechanism of their findings, the authors contend that the environment of a town less than 500,000 is different than the environment of a city of over 5,000,000. Maybe a city has fewer football fields for aspiring athletes to practice on. Or maybe a city is not sufficiently safe for a child to practice the longer hours required to reach expertise, whereas the small town is relatively safer and has several parks and fields. This is only the tip of the iceberg of possible relevant environmental factors. The more important take home message is that the environment and social context that an individual grows up in may indeed impact the athletic performance of that individual.
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