ABSTRACT
This chapter is concerned with developmental changes in various aspects of intelligence and thinking observed in the Munich Longitudinal Study on the Ontogenesis of Individual Competencies (the LOGIC study) from preschool age to early adulthood, and updates a previous review chapter (Schneider, Perner, Bullock, Stefanek, & Ziegler, 1999). When the LOGIC study was started in 1984, two important issues were to assess interindividual differences in intelligence and to assess developmental changes in these differences over the course of the study. Including intelligence measures also allowed us to assess practice effects, that is, the degree to which repeated exposure to intelligence measures increases test performance. As will be apparent from the description of test instruments given below, the majority of intelligence measures used in the study was based on a psychometric approach. However, some of the measures were derived from the assessment of constructs typical of a cognitive developmental approach. The major purpose of adding these tasks was to be able to relate changes in cognitive development assessed by Piagetian-type instruments with changes in psychometric intelligence at different time points, thus exploring the interrelationships among these variables for different ages. Because of time constraints, the design used to investigate this issue was not as systematic as that of many longitu dinal studies focusing solely on intellectual development (e.g., Schaie, 1994). In contrast to those studies, however, developmental trends in intelligence assessed in our longitudinal study could be systematically related to developmental changes in other psychological constructs such as memory, motivation, personality, and academic achievement. Before we present the measures and the results in more detail, we begin with a short overview of the existing literature on developmental changes in intelligence and thinking.
