"To Be, or Not to Be, That Is the Question": Modeling and Differentiation Among Siblings Participating in Organized Youth Sport.

Organized youth sport is a relatively common family context in which sibling dynamics are not well understood. The present study was designed to address two contrasting mechanisms of socialization-modeling and differentiation-in examining older siblings' influence on younger siblings' sport participation. American youth (N = 221) age 10-15 years (M = 12.