Young people report being both emotionally and cognitively engaged in youth activities in ways they are not in other parts of their lives. Research has identified six developmental processes that categorize youths' growth experiences in their activities. These include identity work; developing initiative; learning, emotional competencies; developing peer relationships and knowledge; developing social skills; and acquiring social capital. Using focus group methodology with 55 adolescents (mean age 16 years), the authors use adolescents' own voices to describe these experiences.