Abstract
Adolescence has long been purported to be a period of emotional upheaval, yet relatively little is known regarding normative patterns of change in youth positive and negative affect across the adolescent transition. This study addressed this gap by examining normative patterns of mean-level change in youth positive and negative affect from middle childhood through late adolescence, encompassing the full span of adolescent development. Participants included 665 youth recruited in 3rd, 6th, and 9th grade cohorts (55.0% female; age 9-16 at baseline) who provided self-report ratings of positive and negative affect every 18 months for a period of three years in an accelerated longitudinal cohort design. Multi-level growth curve models revealed that adolescence is characterized by declines in positive affect and non-linear patterns of alternating decreases and increases in negative affect. Patterns of change differed across boys and girls. The findings from this study indicate that adolescence is characterized by normative reductions in positive affect in the context of labile negative affect, with implications for understanding processes of risk and resilience across the adolescent transition.