Childhood participation in sports, cultural groups, and youth groups appears to be related to improved self-esteem for adolescents (McGee, Williams, Howden-Chapman, Martin, & Kawachi, 2006). In a representative study, a researcher compares scores on a standardized self-esteem questionnaire for a sample of n = 100 adolescents with a history of group participation and a separate sample of n = 100 who have no history of group participation.