“Honey, Just Pull Over and Ask”

“Head due north for 3.2 miles, then turn east and keep going for another mile and a half. Look for house number 735.”

“Go past Planet Pizza, then take your second left onto Winding Way, and it’s the third house on the right. There’s a red VW in the driveway.”

As has long been suspected, researchers at the Yerkes National Primate Research Center have turned up evidence that men and women navigate in different ways, due to subtle hormonal changes that take place as the brain develops. Women are more likely to use landmarks in giving directions, while men think in terms of compass directions and distance, say lead researcher Rebecca Herman and Dobbs Professor of Psychology Kim Wallen.

Herman and Wallen studied hormones for clues about the navigational habits of monkeys. They compared normal female and male rhesus macaques to those who differed in their prenatal exposure to specific hormones. Some females and males received a drug that blocks the actions of androgens (male hormones), while a separate group of females received the male androgen testosterone.

After the monkeys reached adulthood, researchers observed them as they navigated an open area to locate food. The researchers varied the consistency of the food locations and the presence of colored markers on food boxes to assess the monkeys’ memory and use of spatial arrangement and landmarks. “When both spatial and marker cues were available, performance did not differ by sex or prenatal treatment,” said Herman. “However, when landmarks gave correct locations, but spatial information was unreliable, females performed better than males.”

Male monkeys whose testosterone exposure had been blocked early in their gestation were more able to use the landmarks to navigate. “They performed more like females,” she said. “This suggests that prenatal testosterone likely plays a role in establishing the sex difference in using landmarks for navigation.”

Wallen says their findings may provide insights into how sex differences figure into abnormal brain development and neuropsychological disorders as well.—M.J.L.



© 2007 Emory University