This chapter deals primarily with the development of various perceptive and cognitive abilities of humans as they mature. It touches on various crucial steps in physical co-ordination, perception of the world around the individual as they mature, as well as the development of social and moral perspectives. For the most part the chapter is focussed on many theories regarding behavior and the nature/nuture complex, supported by a number of experiements and observed behaviors listed throughout each of the sections. One thing that interested me was the discussion of gene expression and the wide variety of effects that experiences may trigger. This is something I've seen happen, some women I've known have developed allergies during pregnancy that persisted indefinitely, as well as the number of behavioral changes based on hormone production, such as the reduction of testosterone in older men and the effect on behavior.