ABSTRACT
It is important to understand as much as we can about how our brains and bodies function and what might go wrong, but this approach can only provide part of the total picture because we are not standard perfect machines that acquire faults. We are complex and individually unique organisms that develop in a natural and social environment. Increasingly, the picture of ourselves as develop ing and changing as we grow and age is being seen as the key to human psychology. The core principle of a developmental per spective is that any particular observation about an individual, e.g. this child is poor at copying or drawing crosses and angles, needs instantly to be related to the child's current developmental goals.
