Reductionism is the argument that we can explain behaviour and experiences by reference to only one factor, such as physiology or learning.
The reductionist view of the world looks for explanations which break things down into smaller constituent parts. This can be powerful, but sometimes provides an explanation which is simplistic, ignoring other important aspects or factors. A holistic view looks at a person as a whole, or perhaps looks at a complex of factors which together might explain a particular behaviour.
