human behavior

Question submitted by Ward Danekas of Franklin Grove, Ill.

The answer appears to be no. A bird will spend hours tossing a pebble in the air, but it's nearly impossible to discern if it's goofing around or honing its talon-eye coordination. Gordon Burghardt, an expert on animal behavior at the University of Tennessee, defines play as behavior that doesn't seem to have a survival purpose, is rewarding in and of itself, and is performed when an animal is fully fed and stress-free.

Advertising agencies live by the aphorism that sex sells because it's one of the most basic, driving forces in our lives. Getting it, however, is a different matter altogether. In the animal kingdom, males and females of many species are known to trade resources for sex. Humans are no different. In the most basic terms, men can be said to offer protection to females, while females offer the promise of offspring to the males (we're talking caveman mentality here; let's leave the modern societal norms aside for a moment).