Supernormal Stimuli

The modern world is filled with puzzling human behaviors. People sit alone in front of a plastic box watching Friends instead of going out with their real buddies; they 'feed' plastic Pocket Pets while shirking real duties. Men have sex with a two dimensional magazine page when a willing woman may be in the next room, and there's a "Department of Defense" in every country when none has a department of "Offense" or "Aggression."

In my new book, Supernormal Stimuli: How Primal Urges OverranTheir Evolutionary Purpose, I describe how human instincts -- for food, sex, or territorial protection -- developed for life on the Savannah 10,000 years ago, not today's world of densely populated cities, technological innovations, and pollution. Evolution has been unable to keep pace with the rapid changes of modern life. We have a glut of larger-than-life objects, from candy to pornography to atomic bombs, that cater to outmoded but persistent drives with dangerous results.

In the 1930s Dutch Nobel laureate Niko Tinbergen found that birds that lay small, pale blue eggs speckled with grey preferred to sit on giant, bright blue plaster dummies with black polka dots. He coined the term "supernormal stimuli" to describe these imitations that appeal to primitive instincts and, oddly, exert a stronger attraction than real things.

Animals encounter supernormal stimuli mostly when experimenters build them. We humans can produce our own: candy, pornography, huge-eyed stuffed animals, diatribes about menacing enemies. Instincts arose to call our attention to rare necessities but now we use them to produce ubiquitous attention-grabbers. The concept of "Supernormal Stimuli" has enormous power to illuminate the alarming disconnect between human instinct and our created environment. Supernormal stimuli are a driving force in many of today's most pressing problems, including obesity, our addiction to television and video games, and the past century's extraordinarily violent wars. Man-made imitations have wreaked havoc on how we nurture our children, what food we put into our bodies, how we make love and war, and even understanding of ourselves.

Becoming aware of supernormal stimuli does more than pull the fire alarm to show how these unfettered instincts fuel dangerous excesses. There's a hopeful message, too. Once we recognize how supernormal stimuli operate, we can craft new approaches to modern predicaments. Humans have one stupendous advantage over Tinbergen's birds -- a giant brain. This gives us the unique ability to exercise self-control, override instincts that lead us astray, and extricate ourselves from civilization's gaudy traps.

Deirdre Barrett is the author of Supernormal Stimuli: How Primal Urges Overran Their Evolutionary Purpose and Waistland: The R/evolutionary Science Behind Our Weight and Fitness Crisis