Individual differences are accentuated during periods of social change: The sample case of girls at puberty.

Abstract
The emergence of new behaviors and the reorganization of psychological structures are often attributed to critical events and crises in the life course. A fundamentally different perspective is offered: Potentially disruptive transitions produce personality continuity, not change. The behavioral responses of adolescent girls to the onset of menarche was studied in a longitudinal study of an unselected birth cohort. Predictions from 3 rival hypotheses about the relation between pubertal change and social psychological change were first tested: the stressful change, off time, and early-timing hypotheses. The results supported the early-timing hypothesis. Whether stressful, early menarche generated new behavioral problems or accentuated premenarcheal dispositions was then tested. The results supported an accentuation model: Stressful transitions accentuated behavioral problems among girls who were predisposed to behavioral problems earlier in childhood. Speculations are offered for a broader theory about the role of individual differences in the life course.