Marilyn Monroe had one and it drove men crazy.  Women everywhere wanted an hourglass figure just like hers.  Many of them still do.  A recent scientific study, however, suggests that same curvy figure may not be such a good thing after all, at least from an evolutionary perspective.

Elizabeth Cashdan, an anthropoligist at the University of Utah, says women who have more fat around their tummies are more likely to be stronger physically, better equipped to handle stress, and be more competitive than their more curvaceous counterparts.  They’re more likely to enjoy financial success, too.

Cashdan says buxom women with tiny waists and curvy hips are generally thought to be more fertile than others and to experience lower rates of chronic illness.  These instinctive attributes may influence a man’s choice of mate when he’s looking for a healthy woman to bear his children.

The way a person’s body fat is distributed depends on androgens, hormones, including testosterone, that are most often associated with men.  A high level of androgens cause fat to accumulate around the middle, making women more cylindrical than curvy like an hourglass.  It’s these same androgens that fuel the competitive edge and increase body strength.

Another hormone, cortisol, influences the way a person responds to stress and it also causes fat to accumulate along the waistline.  During times of prolonged stress, the benefits of both the androgens and cortisol are likely to outweigh the benefit of a more estrogen-rich curvy body.

In non-Western societies of the world, where food can be scarce and women contribute as much or more than their men, men seem to prefer less curvy women.  British and Danish men, too, don’t value an hourglass figure as highly as those in Greece, Japan, and Portugal.  Sexual equality is more pronounced in Great Britain and Denmark but women in Greece, Japan, and Portugal are not so economically independent, relying more heavily on their mates for financial gain and protection.

Cashdan says that a man’s preference isn’t the only thing that matters when it comes to a woman’s looks and her curves, or lack thereof, sends strong signals.  The journal, ‘Current Anthropology,’ carries the full details of Cashdan’s study in its December issue.