How to do politically correct research about innate sex difference.

The rule is: always portray whatever you find in the female as superior.

Here's today's example:

Chimpanzees like to snack on termites, and youngsters learn to fish for them by poking long leaf spines and other such tools into the mounds that colonies build.

In a paper to be published in the journal Animal Behavior, researchers found that female chimps in the Gombe National Park in Tanzania picked up termite fishing at a mean age of 31 months, more than two years earlier than the males.

The females seem to learn by watching their mothers, said the paper's author, Dr. Elizabeth V. Lonsdorf, director of field conservation at the Lincoln Park Zoo in Chicago.

Dr. Lonsdorf said that typically, when a young male and female are near a mound, "she's really intently termite fishing, and he's spinning himself in circles."...

[Under experimental conditions], adult females were [using the leaf tool] and a young female watched carefully and began to pick up the skills, she said. Two young males did not fare as well - one simply sat next to his mother and tried to steal some mustard from her, Dr. Lonsdorf said.

The behavior of both sexes may seem familiar to many parents, she said, adding, "The sex differences we found in the chimps mimic some of the findings from the human child development literature."

She pointed out, however, that at least in the case of chimps, each is doing something important, since the males' play is practice for later dominance behavior.

"They're doing stuff that's really appropriate," she said.