Performance of Older versus Younger Brothers: Data from Major League Baseball

Abstract

Batting and pitching records and career lengths of 312 sets of brothers who became major league baseball players were compared. Older brothers at non-pitching positions ( N = 262) had significantly higher batting averages and longer careers than their younger siblings. Differences for pitchers were not statistically significant. The results corroborate other studies that firstborns are more likely than later born siblings to be higher achievers, but different factors may be operative for pitchers.