The Young Athlete: A Sports Doctor's Complete Guide for Parents (Metzl& Shookhoff):

 “…..kids who participate in organized sports do better in school, have better interpersonal skills, are more team oriented, and are generally healthier.  Participation in sports provides opportunities for leadership and socialization, as well as the development of skills for handling success and failure.  Moreover, when playing games, children learn how rules work. They see how groups need rules to keep order, that the individual must accept the rules for the good of the group, that rules entail a consideration of the rights of others. They also learn about competition, but within a restricted and safe system where the consequences of losing are minimized."