Supernormal Stimuli

The author of a new book on behavioral evolution explains how primal urges overrun their original purpose

Deirdre Barrett
Feb 18, 2010
Put a mirror on the side of a beta fighting fish's aquarium and the gaudy iridescent male will beat himself against the glass, attacking a perceived intruder. A hen lays eggs day after day as a farmer removes them for human breakfasts -- 3,000 in a lifetime without one chick hatching, but she never gives up trying. The healthiest, largest male chickadees have the highest crests on their heads and they are sought after as mates. When researchers outfit runt males with little pointed caps, much like the human dunce cap, females line up to mate with them, forsaking the naturally fitter, hatless males.
These animal behaviors look funny to us . . . or sad. The reflexive instincts of dumb animals. But then there's a jolt of recognition: just how different are our endless wars, our modern health woes, our melodramatic romantic and sexual lives?In my new book, linkurl:__Supernormal...
Correction (February 21): The original version of this article incorrectly estimated that a chicken lays 30,000 eggs in its lifetime. The actual figure is 3,000. The Scientist regrets the error.