Deirdre Barrett


On her book Supernormal Stimuli: How Primal Urges Overran Their Evolutionary Purpose

Cover Interview of July 19, 2010

The wide angle

Niko Tinbergen clearly thought ethological principles applied to man.  But while waxing eloquently for pages about bee-wasps and sticklebacks, he devoted the occasional sentence or two to man.

The major push to incorporate Darwin into psychology has come under the term “evolutionary psychology.”  In their primer, Leda Cosmides and John Tooby are fond of saying that “our modern skulls house a stone age mind.”

Evolutionary psychologists view the brain as a biological computer with circuits which evolved to solve problems faced by humans and pre-human ancestors.  Cosmides and Tooby point out that consciousness is a small portion of the contents and processes of the mind.  They describe how conscious experience can mislead individuals to believe that that their thoughts are simpler than they actually are. Most problems experienced as easy to solve are actually very complex and are driven and supported by elaborate brain circuitry.

Evolutionary psychologists argue that this is not just another swing of the nature/nurture pendulum. They are not stating as baldly as Tinbergen did in his landmark talk that “Nature is Stronger than Nurture.”  Their position instead is that nature/nurture is a false dichotomy: more nature allows more nurture.

In evolutionary psychology, “learning” is not an explanation—it is a phenomenon that requires explanation.  Cosmides and Tooby use the example of a larger brained elephant not being able to learn English, not because its brain is less complicated nor even less learning-disposed: elephants have many aspects of memory better than ours.  Rather we have evolved specific neural circuits that enable certain types of communication that the elephant has not evolved.

Though sociobiologists and evolutionary psychologists have incorporated many of Niko Tinbergen’s ideas, they have not used the concept of Supernormal Stimuli.

I believe that the concept of Supernormal Stimuli is the single most valuable contribution of ethology for helping us understand many issues of modern civilization.  So my book examines a range of human dilemmas from the standpoint of Supernormal Stimuli, interweaving other relevant concepts from all of these evolutionary disciplines.