INTERNATIONAL JOURNAL OF BEHAVIORAL DEVELOPMENT, 1994, 17(3), 447—467 Transitional Processes in Social Cognitive Development: A Longitudinal Study Marvin W. Berkowitz Marquette University, Milwaukee, USA Monika Keller Max Planck Institute for Human Development and Education, Berlin, Germany f * h ~ ~ ~ h,, ~ C’.~. ,L.. ,.~ ~ ~ ~ ~ ~ aiiu Feldman’s consolidationltransition model to substages and subcontents of Selman’s stages of friendship reasoning in a six-year longitudinal study of 97 9- to 15-year-old children. It was hypothesised that individuals exhibiting reasoning above their own modal stages would be more likely to experience a developmental advance in modal reasoning, even when examined at the level of substage and subcontent. This was confirmed; however, the amount of variance in above mode reasoning was not related to development. Finally, controversies in the prior literature were explained by methodo- logical differences. It was concluded that the Piagetian processes underlying the Snyder and Feldman model were supported. INTRODUCTION Two neglected aspects of cognitive stage development are (1) processes of change in reasoning levels, and (2) microdevelopmental analysis. Processes of cognitive level change have been considered theoretically (Piaget, 1967), but empirical studies are comparatively rare (Miller, 1981), prob- ably because the issues are complex and difficult to test empirically, and because many of the relevant issues require longitudinal data. What research does exist tends to focus on forces external to cognition, such as social influence, rather than on the more central internal forces, such as cognitive disequilibrium (cf. Snyder & Feldman, 1977). Stage development can be examined holistically (molar analysis) or at the level of subcomponents (molecularly). Despite a recent trend that Requests for reprints should be sent to Marvin W. Berkowitz, Department of Psychology, Marquette University, Milwaukee, Wisconsin 53233, USA. © 1994 The International Society for the Study of Behavioral Development