If you were to examine the birth certificates of every soccer player in next month's World Cup tournament, you would an unusual tendency:elite soccer players are more likely to have been born earlier months in the year than later. If you then examined the European national youth teams that supply many World Cup player, this tendency would be even more noticeable. In recent English teams, for instance, half the elite teenage soccer players were born in January,February or March. In Germany, fifty-two were born in the first three months, with just four players born in the first three. What might account for this?