The basic idea of psychology is that there exists “One Basic Psychology” common to all humans, and that any individual personalilty (the individual expression of that particular psychology) can be found on a normal curve distribution, a concept with which I have never felt comfortable. Imagine each person having a common set of qualities , and each individual person may have a combination of more or less of the basic human qualities.
The people on the ends of the curve are the wierdos.
The meta level theory which explains the relationship between the unique individual expressions and a working ? order? peaceful? functioning? society is that some distributions are more amenable than others.
But the quality of the society is determined by the relationships between the individual and the individual behavour is a product of the relationship between the combination of the basic qualities in the individual.
Psychology tries to explain behavour by understanding why people do things.
Sociology on the other hand, uses the concept of “normative behavior, ” i.e. it observes how people behave and differentiates more common behaviors from less common behaviors.
There is an old saying, “I eat, I sleep and I shit.” No one has to wonder or ask why.
A 18th Century philosopher suggested that the reason some people have “mental problems” is because each person has two selves, an empirical or real self and an ideal self. The first is easy to understand, its how we behave, what we do is our real self.
Our ideal self is the person we want to be , or perhaps should be, and is a different self. Each person has to learn to live with both selves. Those that cannot live with both selves have mental problems.
That may sound simplistic, but it is the basis for the psychological theory of The Divided Self. But the “therapies” using the theory of the divided self argue the path to a well adjusted person is the unification of the selves into one, the original theory just described the situation with no judgement.