In psychology one can begin to describe the whole situation by roughly distinguishing the person (P) and his environment (E). Every psychological eve… - Kurt Zadek Lewin

Whatever is common to children of a given age is set up as the fundamental character of that age. The fact that three-year-old children are quite often negative is considered evidence that negativism is inherent in the nature of three-year-olds, and the concept of a negative age or stage is then regarded as an explanation for the appearance of negativism.

At the present we have no adequate scientific method for representing the psychological life span. In accord with the general methods of psychology, the study of environmental influences began with classification and statistics... they gave us excellent descriptions of the home environment. The method of representation is partly akin to that of the novelist i.e., one trying to make as lifelike picture of the situation as possible by choosing expressive words and bringing out significant traits with examples. In general, the descriptions that have been made valuable to science have not been those made by scientific methods. Where theoretical concepts have been introduced with the concrete description, they often stand out as something alien. In stead of scientific descriptions they are nothing more than speculative interpretation.

It is not the similarity or dissimilarity of individuals that constitutes a group, but interdependence of fate.