There is a consensus that the crises children encounter during the transition period might impact negatively on children's learning and development. However, from cultural-historical perspective, qualitative leap in development can hardly be achieved without crises. This paper, drawing upon cultural-historical theory as the framework and by using…

Data on the relationships between cognitive and physical phenotypes, and a deficit of fragile X mental retardation 1 (FMR1) gene-specific protein product, FMRP, are presented and discussed in context with earlier findings. The previously unpublished results obtained, using standard procedures of regression and correlations, showed highly…