Go Past the Cave, Turn Left at the Mammoth Herd ...

We know men and women think differently, often using opposite sides of the brain to do the same task. Now scientists suspect this difference may be evolutionary, a vestige of the hunter-gatherer era when survival of the tribe hinged upon a division of labor between men and women.

University of Saskatchewan researchers, in a study published in the June issue of Behavioral Neuroscience, discovered sharp gender differences in navigational strat- egies. A group of 42 college students--22 women and 20 men--were asked to find four unknown destinations on campus using written instructions. Half were given directions in the form of directional cues and measured distances: Go north for 100 meters, then proceed east for 500 meters, for example. The others were given photos of landmarks in sequential order to use as guides, with instructions such as to turn right at the purple doors.

In a separate experiment, 40 students, equally divided between men and women, were given a different navigational task that required them to map out the correct route on a sheet of paper. Half were given directional cues; the other half received landmark guides.

Both tests came to roughly the same conclusion: Women were more proficient when they used landmarks to find their way, which is a strategy that relies more on verbal descriptions. Men were better at employing measures of distance and directions to plot the correct course, which suggests men are better at visualizing abstract spatial relationships.

Scientists speculate that this spatial skill, a left-brain function, may have become predominant when hunters had to find their way over long distances without the benefit of landmarks. “Evolution favored men with this type of knowledge of the environment,” says Deborah M. Saucier, a study coauthor and psychologist at the university, in Saskatoon, Canada. Women needed to keep track of where they planted vegetables or stored food, so the right-brained descriptive landmarks were key.

These findings also suggest an answer to the age-old question: Why won’t men ask for directions when they’re lost? “This seems to be an innate bias,” says Saucier. “Men use spatial strategies, while women have much better verbal skills.”