The transition from preschool to elementary school requires high adaptive behaviours. Our study's aim is to analyze the reciprocal effects between self-regulation and behaviour problems during this transitional phase. Study results are based on longitudinal data collected at preschool and elementary school. Children's level of behaviour problems…

In this study an attempt was made to obtain a developmental dimension for estimating longitudinal development on the basis of cross-sectional data. To check the validity of this approach, the cross-sectional data were compared with true longitudinal data. Forty-three public school children were given a series of conservation tasks in four…