Bonnie Erbe: Brain differences

A new UCLA study reports on how different parts of men's versus women's brains are stimulated in reaction to pain. This Mars-Venus material is precious and important. The more science separates and studies male and female biology, the more we realize men and women are quite different -- fascinating stuff. What is dangerous however, is how some scientists categorize these differences.

UCLA quotes study co-author Dr. Emeran Mayer, professor of bio-behavioral sciences, and medicine, physiology and psychiatry (whew!), as saying "This growing base of research will help us develop more effective treatments based on a new criteria: gender." OK, great. But here's the problem. UCLA researchers took positron emission tomography (PET) brain scans of patients while they were experiencing mild pain. They found "some overlapping areas of brain activation in men and women" and "several areas" where "male and female brains reacted differently when given the same pain stimulus. The female brain showed greater activity in limbic regions, which are emotion-based centers. In men, the cognitive regions, or analytical centers, showed greater activity." Uh oh, I can tell where this is heading, and it's not good.

Co-author Dr. Bruce Naliboff went on to explain, "The reason for the two different brain responses may date back to primitive days, when the roles of men and women were more distinct." According to UCLA's Web site quoting Naliboff, "men's cognitive areas may be more highly triggered because of the early male role in defending the homestead, where in response to stress and pain, the brain launched a calculated fight-or-flight reaction. The female limbic regions may be more responsive under threat because of their importance in triggering a nurturing and protecting response for the young, leading to a more emotion-based response in facing pain and stress."

What, who, huh? Are these scientists really buying into a retro view of females as emotional, nurturing, protective beings dating back to the genesis of Homo Erectus, and males as the sole defenders of the homestead? If so, they need to brush up on their data.

The study of anthropology is evolving rapidly. A study released earlier this year by James O'Connell, director of the Archaeological Center at the University of Utah in Salt Lake City and lead author of a recent paper about the subject in Journal of Human Evolution, posits male homo sapiens did a whole lot less hunting and females a whole lot more hunting and gathering, than previously believed. As reported on ABC News' Web site, "a renewed look at archaeological records and observations of a contemporary hunting and gathering tribe in East Africa suggest the key roles in nourishing the evolution of people's ancestors may have been played by females -- mothers and grandmothers."

In other words, many of our stereotyped notions of primitive man defending the home front -- constantly stalking and bringing home large game to feed the family -- are just that: stereotypes that do not reflect reality. Similarly, the stereotypical primitive female who sat in the cave minding the baby, is now being reconsidered and scientists are coming to the conclusion she probably never existed. A more accurate portrayal of a primitive female is one who shared equally in if not superseded her mate's capacity to put food on the table, I mean, the floor.

"There's a longstanding theory that nuclear families where the man brings home the food and the woman takes care of the young are the basic deal. That may or may not always have been true," said O'Connell. "We're skeptical it was true in the past."

So scientists, please keep up the good work and cast off the bad. Study biological gender differences, because we're finding more and more they do exist and are important to understand. But lay off the stereotypical hypotheses about why they exist, until we know more.

Bonnie Erbe, host of the PBS program "To the Contrary," writes this column for Scripps Howard News Service. E-mail bonnieerbe@CompuServe.com.