Within the study of psychology there are many branches one could take. For example, there is Industrial-Organizational Psychology, the study of behaviors and best practices in the workplace. There is Clinical Psychology, the view most of us have when we think of psychology and picture a person on a couch and the psychologist in the chair with a notepad. One of the more interesting views of psychology is that of Evolutionary Psychology. A full overview of the entire study of Evolutionary Psychology is outside the scope of this writeup. However, the understanding of the goals, history, and principles behind it are important in one's general knowledge of the subject.

Evolutionary Psychology came into existence in 1871 with the principles and questions being asked long before that time. The primary goal of Evolutionary Psychology is to discover and understand the design of the human mind. Unlike some forms of psychology, Evolutionary Psychology is a way of thinking about psychology that can be applied to any topic within it (Kenyon, 2000). Using this view the mind becomes a set of information processors designed by natural selection to solve adaptive problems faced by our hunter-gatherer ancestors (Tooby et al., 1997).

It is important to understand the difference between biology and psychology to understand the history of Evolutionary Psychology. Biology is built upon the foundations provided by Darwin's theory of evolution. In contrast, psychology rests on the Standard Social Science Model. This model contains the barely concealed idea that human behavior is guided by reason, whereas non-human animal behavior is influenced by instinct. According to the Standard Social Science Model the human mind is blank at birth (a tabula rasa - blank slate) and is filled as the result of experiences during the individual's lifetime. Behaviorism is a classic example of this approach to understanding human behavior.

This is what makes Evolutionary Psychology stand out. In the final pages of Origin of Species, Darwin predicted, "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." In 1890, William James extended that statement into his book Principles of Psychology. In his book, James used the term "instincts" to refer to specialized neural circuits that are common to every member of a species and the product of that species' evolutionary history. Taken together, such circuits constitute (in our own species) what one can think of as "human nature". In other words, science had always thought that humans were more advanced because we worked off reason instead of instinct. Now the theory was proposed that humans were more advanced not because of reason, but that we had greater instincts that were more efficient then that of other animals. James argued that humans tend to be blind to the existence of these instincts precisely because they work so well -- because they process information so effortlessly and automatically. They structure our thought so powerfully that it can be difficult to imagine how things could be otherwise. As a result, we take "normal" behavior for granted. We do not realize that "normal" behavior needs to be explained at all. This "instinct blindness" makes the study of psychology difficult. To get past this problem, James suggested that we try to make the "natural seem strange." (James, 1890)

"It takes...a mind debauched by learning to carry the process of making the natural seem strange, so far as to ask for the why of any instinctive human act. To the metaphysician alone can such questions occur as: Why do we smile, when pleased, and not scowl? Why are we unable to talk to a crowd as we talk to a single friend? Why does a particular maiden turn our wits so upside-down? The common man can only say, Of course we smile, of course our heart palpitates at the sight of the crowd, of course we love the maiden, that beautiful soul clad in that perfect form, so palpably and flagrantly made for all eternity to be loved!

And so, probably, does each animal feel about the particular things it tends to do in the presence of particular objects. ... To the lion it is the lioness which is made to be loved; to the bear, the she-bear. To the broody hen the notion would probably seem monstrous that there should be a creature in the world to whom a nestful of eggs was not the utterly fascinating and precious and never-to-be-too-much-sat-upon object which it is to her.

Thus we may be sure that, however mysterious some animals' instincts may appear to us, our instincts will appear no less mysterious to them." (William James, 1890)

Applying this outlook - making the natural seem strange - requires a way of twisted thinking that can be difficult to picture. Yet this view is the precise outlook of Evolutionary Psychology. Often times the study of natural competencies is not fully examined under the premise that they do not need to be explained. As a result, social psychologists are disappointed unless they find a phenomenon "that would surprise their grandmothers", and cognitive psychologists spend more time studying how we solve problems we are bad at, like learning math or playing chess, than ones we are good at. But our natural competences -- our abilities to see, to speak, to find someone beautiful, to reciprocate a favor, to fear disease, to fall in love, to initiate an attack, to experience moral outrage, to navigate a landscape, and myriad others -- are possible only because there is a vast and heterogeneous array of complex computational machinery supporting and regulating these activities (Tooby, et al., 1997). Because this machinery works so well, humans suffer from "instinct blindness."

An evolutionary approach to psychology provides explanations for this instinct blindness. It allows for natural competencies by indicating that the mind is a heterogeneous collection of these competences. It also provides positive theories of these collection's designs. Einstein once commented, "It is the theory which decides what we can observe". Combining an evolutionary focus with the biological system can be a valuable tool for psychologists working to understand the human mind. Theories of adaptive problems can guide the search for the cognitive programs that solve them; knowing what cognitive programs exist can, in turn, guide the search for their neural basis.

There are several guiding principles of Evolutionary Psychology that build these theories:

  1. "Modern skulls house a stone age mind." This is a catchy way of conveying the idea that human evolution occurred in a very different environment to the one in which we now live. Human's evolution is thought to have started 68-million years ago when we diverged from our primate ancestors. Evolutionary psychologists believe that natural selection designed our minds for life in an environment resembling the African savannah, in which our hunter-gatherer ancestors lived for thousands of years. For 99% of our evolutionary history we probably lived in hunter-gatherer societies. It has only been about 10,000 years since humans first started growing their own food. The technical term used to refer to the environment in which we evolved is the Environment of Evolutionary Adaptedness (EEA). The EEA does not refer to some short period of time in our past. It refers to an array of factors that have influenced inclusive fitness during our evolution over the last 200,000 years. See Daly & Wilson (1999) for a very good discussion of this important distinction.
  2. The human brain consists of neural circuits designed by natural selection to solve problems that our ancestors faced during our evolutionary history. Our minds are an adaptation. Adaptions evolve to meet challenges in the environment, challenges faced in our EEA.
  3. Most of what goes on in the mind is unconscious. Most problems that we think are easy to solve are in fact very difficult to solve and require complicated neural circuitry. Consider vision, vision appears easy - open your eyes and you see the world - but this apparent simplicity hides a complex evolved system that we have not been able to reproduce artificially.
  4. Different neural circuits are specialized for solving different adaptive problems. Evolutionary psychology views the mind as consisting of specialized modules that have evolved to cope with adaptive problems. In contrast, psychologists have tended to view the mind as consisting of general-purpose circuits involved in many different behaviors e.g. learning, intelligence, memory, reasoning, decision-making. (Steen, 2000)

In summary the field of Evolutionary Psychology is a complex field involving theories from modern psychology, biology and the Standard Social Science Model. Using these theories it attempts to create a way of thinking about psychology to help discover and understand the design of the human mind. There is much information available to those who are interested, please see the references below for further reading.


  • Center for Evolutionary Psychology -
  • Leda Cosmides & John Tooby Evolutionary Psychology - A Primer, 1997 -
  • Francis F. Steen Cognitive Adaptations, 1998 -
  • Dr. C.A.P. Kenyon Evolutionary Psychology, 2000 -
    (The above URL was wrapped cuz it was too long!)
  • Barkow, J., Cosmides, L. and Tooby, J. 1992. The Adapted Mind: Evolutionary psychology and the generation of culture. NY: Oxford University Press.
  • Daly & Wilson, Human evolutionary psychology and animal behaviour, Animal Behaviour, 57, 509-519, 1999.