ABSTRACT
Behavior changes after birth by a process of phenotype differentiation based upon a specific sequence of events. The disappearance of the behavioral patterns involved during the restructuring is probably an accompanying phenomenon of the reorganization. The reflexive grasping, however, does not disappear, but exists alongside voluntarily directed grasping. A great deal of learning goes on regarding the fine tuning of social behavior and the utilization of individual strategies, but it would be a mistake to regard a child as initially socially incompetent. The play-face and other affectionate signals are social gestures at an infant's disposal, but, in addition, a great deal is undoubtedly learned in the fine tuning of social behavior. In the case of phylogenetically adapted behaviour, the chapter discusses the growth and differentiation of neuronal networks, sensory organs, and executing organs. Environmental factors may have an influence in various ways during the growth period.
