The Long Dive of a Woman's Sex Drive

Imagine, if you will, a slide whistle -- it starts out high and then declines. That's also the soundtrack to a woman's sex drive in the same relationship over a course of years, according to a German study.

Now imagine a test of the Emergency Broadcast System, that consistent hum that stays steadfast in its signal and doesn't seem like it will ever end. That's the soundtrack for the men.

A BBC news story reports that researchers at Hamburg-Eppendorf University studied 530 men and women found that men's interest in sex stays the same, like that EBS test, no matter how long they've been in a relationship. Between 60 percent and 80 percent still wanted it regularly over time. As for the ladies, 60 percent of 30-year-old women started out hot in relationships, but "within four years of the relationship this figure fell to under 50 percent," and in 20 years only 20 percent remain focused horndogs.

That would seem to upend the stereotypes of the romantic, ring-happy woman and the skirt-chasing commitment-phobic man. But psychologist and lead author of the study Dr. Dietrich Klusmann points to evolutionary reasons for both male attention and female distraction.

"For men, a good reason their sexual motivation to remain constant would be to guard against being cuckolded by another male," Klusmann says. It sounds simple enough: Keep paying attention so she doesn't seek attention elsewhere.

This constancy doesn't square with the idea a lot of us have -- OK, I have -- of the promiscuous male, biologically driven to throw his DNA around like mardi gras beads to any chick who'll accept.

In looking for an explanation on how a wandering eye and a constant heart could jibe, I found this essay by David P. Barash, professor of psychology at the University of Washington. In "Deflating the Myth of Monogamy," Barash quotes sociobiologist Robert Trivers, saying males have a "mixed reproductive strategy."

Males, Barash says "establish a mateship with a designated female ... while also making themselves available for E.P.C.'s (extra-pair copulations) with other females, whom they will not assist." He also brings up the cuckolding theory.

That men are capable of keeping a lot of balls in the air for a long time comes as no surprise to me.

But what about women? Are we really more fickle than we imagine ourselves to be? Most of us seem to want secure, mature love, but once we've opened that gift do we really start yawning and wondering what else is under the tree?

The fading interest some women exhibit sounds less revolutionary than evolutionary. The BBC says "He (Dr. Klusmann) said animal behavior studies suggest this could be because females may be diverting their sexual interest towards other men, in order to secure the best combinations of genetic material for their offspring.

"Or, he said, this could be because limiting sex may boost their partner's interest in it."

Dr. Helen Fisher wrote a bit about those genetic combos in her 2004 book "Why We Love: The Nature and Chemistry of Romantic Love." Looking at partner switching from an anthropological viewpoint, Fisher writes that "primitive divorce" among our early ancestors "had genetic payoffs: Men and women who "remarried" could bear young with a different partner, creating beneficial variety in their lineage."

So, as one of my friends suggested, it might sometimes be more than the fact that he won't take the garbage out.

The more of this kind of stuff I read (and I read a fair amount of it), the more I wonder if anyone in Vegas has calculated the odds of the average person making it to "happily ever after." Not whatever-after, where you're cutting all kinds of emotional corners, but the whole package -- warm, fuzzy love and hot monkey love, with the same person, true blue, until somebody is dead.