Behavioral perspective is the theory that the majority of all behavior is learned from the environment after birth. Freewill is considered to be an illusion, because our environment determines behavior. Behaviorists believe that only behavior should be observed, not our minds, since we cannot see into other people’s minds. There is no way to know if a person is honestly answering a question so it is irrelevant. Behaviorists use strict laboratory experiments, usually on animals, such as rats or pigeons. They test animals because the laws of learning are universal, there are only a quantitative difference between animals and humans, and animals are practically and ethically more convenient to test.

Cognitive psychologists think that mental processes should and can be investigated scientifically. Models of psychological functions can be proposed, and these models can be carried out to confirm, refute, or modify them by testing observable behavior and conscious report. Cognitive processes actively organize and manipulate information we receive. Most cognitive psychologists use a nomothetic approach to discover human cognitive processes. Some have also adopted idiographic techniques such as laboratory experiments and case studies.