Evolutionary psychology is primarily a biological approach to the discipline of psychology by considering the topic from an evolutionary biological understanding of the brain. The goal of research in evolutionary psychology is to discover and understand the design of the human mind. Evolutionary psychology is an approach to psychology, in which knowledge and principles from evolutionary biology are put to use in research on the structure of the human mind.
It is not an area of study, like vision, reasoning, or social behavior. It is a way of thinking about psychology, as was cognitive psychology when it was first brought forth, that can be applied to any topic within it. In this view, the mind is a set of information-processing machines that were designed by natural selection to solve adaptive problems faced by our hunter-gatherer ancestors.
The Basis of Evolutionary Psychology
The thinkers that devised this approach to psychology seem to have begun with the father of modern evolution, Charles Darwin. One work on the topic cites Darwin's Origin of Species thus: : "In the distant future I see open fields for far more important researches. Psychology will be based on a new foundation, that of the necessary acquirement of each mental power and capacity by gradation."
Evolutionary psychologists will also turn to William James, one of the first writers on what is modern psychology today who published his Principles of Psychology in 1890. James put great stock in the importance of instincts, both in animals and in humans. This term was used to refer (roughly) to specialized neural circuits that are common to every member of a species and are the product of that species' evolutionary history. Taken together, such circuits constitute (in our own species) what one can think of as "human nature".
Evolutionary Psychology and the rest of the Discipline
Because it is biology-based, evolutionary psychology finds itself at theoretical odds with much of the rest of the theories and assumptions currently in play in the field. Evolutionary psychologists dismiss much of the thinking that has gone on since Freud - the behaviorists, the Gestalt movement, the cognitive theory, social psychology - and choose to apply a series of basic principles which they believe lend credence to their theory that human behavior can be traced to evolved biological traits. They offer up five basic principles:
Principle 1. The brain is a physical system. It functions as a computer. Its circuits are designed to generate behavior that is appropriate to your environmental circumstances.
Principle 2. Our neural circuits were designed by natural selection to solve problems that our ancestors faced during our species' evolutionary history.
Principle 3. Consciousness is just the tip of the iceberg; most of what goes on in your mind is hidden from you. As a result, your conscious experience can mislead you into thinking that our circuitry is simpler that it really is. Most problems that you experience as easy to solve are very difficult to solve -- they require very complicated neural circuitry.
Principle 4. Different neural circuits are specialized for solving different adaptive problems.
Principle 5. Our modern skulls house a stone age mind.
