Menus Subscribe Search

For Women, Biological Clock Is an Aphrodisiac

• June 28, 2010 • 11:54 AM

New research suggests women think more about sex, and engage in intercourse more frequently, as their fertility declines.

According to conventional wisdom, men have sex on the brain from puberty until, roughly, death. The Kinsey Institute, which uses somewhat more refined measurements, reports 54 percent of men think about sex every day or several times a day. It adds this is true of only 19 percent of women, making for quite a gender gap.

However, new research suggests that for females, the answer to that question may vary considerably depending upon one’s age.

According to a new study published in the journal Personality and Individual Differences, women’s interest in sex peaks between age 27 and 45. A research team led by psychologist Judith Easton of the University of Texas at Austin concludes this is an unconscious reaction to declining fertility.

A total of 827 women, recruited from the UT community and from Craigslist.com, completed a detailed online survey that included questions about their sexual desires and behaviors. They were grouped into three age categories: 18-26 (high fertility); 27-45 (reduced fertility); and 45 plus (menopausal and post-menopausal).

Those in the middle group were dubbed “RE women,” which stands for “reproduction expediting.” (One can only hope that shorthand term seeps into the culture. “See those two over there?” one man drinking at a bar asks another. “They’re RE. I know it.”)

The study reveals these 27- to 45-year-old females “think more about sex, have more frequent and intense sexual fantasies, are more willing to engage in sexual intercourse, and report actually engaging in sexual intercourse more frequently than women of other age groups,” the researchers report.

Compared to older or younger women, RE women are more willing to engage in sex after knowing a partner for either one month, one week or one evening. Controlling for the number of children the women had, or whether they consciously desired to have a child, did not change the results.

And where does this urge to, er, expedite arise from? “We hypothesized women evolved a psychological mechanism — a reproduction expedition adaptation — that motivated them to capitalize on their remaining fertility before likelihood of conception between less probable,” the researchers write.

“Modern women’s sexual psychology is a consequence of such evolved mechanisms,” they add. “One key design feature of this adaptation is an increased desire and willingness to engage in sexual activity during the period of declining fertility.”

The researchers concede their findings may simply reflect the fact older women tend to have more sexual experience, and this leads to their “increasing comfort with sexuality.” But they add that “this alternative explanation cannot account for why, in the present study, menopausal women consistently displayed decreased sexual motivations and behaviors.”

So according to Easton and her colleagues, the ticking of the biological clock is loud and clear even in women who have no desire for children (or additional children). They conclude that, while it may never penetrate the conscious mind, women feel an urge to “facilitate conception before the window of opportunity closes.” Men: You have been notified.

Subscribe to Miller-McCune

Tom Jacobs
Staff writer Tom Jacobs is a veteran journalist with more than 20 years experience at daily newspapers. He has served as a staff writer for The Los Angeles Daily News and the Santa Barbara News-Press. His work has also appeared in The Los Angeles Times, Chicago Tribune, and Ventura County Star.

More From Tom Jacobs

A weekly roundup of the best of Pacific Standard and PSmag.com, delivered straight to your inbox.

Recent Posts

September 1 • 1:00 PM

Television and Overeating: What We Watch Matters

New research finds fast-moving programming leads to mindless overeating.



September 1 • 6:00 AM

Why Someone Named Monty Iceman Sold Doogie Howser’s Estate

How unusual names, under certain circumstances, can lead to success.



August 29 • 4:00 PM

The Hidden Costs of Tobacco Debt

Even when taxpayers aren’t explicitly on the hook, tobacco bonds can cost states and local governments money. Here’s how.


August 29 • 2:00 PM

Why Don’t Men and Women Wear the Same Gender-Neutral Bathing Suits?

They used to in the 1920s.


August 29 • 11:48 AM

Your Brain Decides Whether to Trust Someone in Milliseconds

We can determine trustworthiness even when we’re only subliminally aware of the other person.


August 29 • 10:00 AM

True Darwinism Is All About Chance

Though the rich sometimes forget, Darwin knew that nature frequently rolls the dice.


August 29 • 8:00 AM

Why Our Molecular Make-Up Can’t Explain Who We Are

Our genes only tell a portion of the story.


August 29 • 6:00 AM

Strange Situations: Attachment Theory and Sexual Assault on College Campuses

When college women leave home, does attachment behavior make them more vulnerable to campus rape?


August 29 • 4:00 AM

Forgive Your Philandering Partner—and Pay the Price

New research finds people who forgive an unfaithful romantic partner are considered weaker and less competent than those who ended the relationship.


August 28 • 4:00 PM

Some Natural-Looking Zoo Exhibits May Be Even Worse Than the Old Concrete Ones

They’re often designed for you, the paying visitor, and not the animals who have to inhabit them.


August 28 • 2:00 PM

What I Learned From Debating Science With Trolls

“Don’t feed the trolls” is sound advice, but occasionally ignoring it can lead to rewards.


August 28 • 12:00 PM

The Ice Bucket Challenge’s Meme Money

The ALS Association has raised nearly $100 million over the past month, 50 times what it raised in the same period last year. How will that money be spent, and how can non-profit executives make a windfall last?


August 28 • 11:56 AM

Outlawing Water Conflict: California Legislators Confront Risky Groundwater Loophole

California, where ambitious agriculture sucks up 80 percent of the state’s developed water, is no stranger to water wrangles. Now one of the worst droughts in state history is pushing legislators to reckon with its unwieldy water laws, especially one major oversight: California has been the only Western state without groundwater regulation—but now that looks set to change.


August 28 • 11:38 AM

Young, Undocumented, and Invisible

While young migrant workers struggle under poor working conditions, U.S. policy has done little to help.


August 28 • 10:00 AM

The Five Words You Never Want to Hear From Your Doctor

“Sometimes people just get pains.”


August 28 • 8:00 AM

Why I’m Not Sharing My Coke

Andy Warhol, algorithms, and a bunch of popular names printed on soda cans.


August 28 • 6:00 AM

Can Outdoor Art Revitalize Outdoor Advertising?

That art you’ve been seeing at bus stations and billboards—it’s serving a purpose beyond just promoting local museums.


August 28 • 4:00 AM

Linguistic Analysis Reveals Research Fraud

An examination of papers by the discredited Diederik Stapel finds linguistic differences between his legitimate and fraudulent studies.


August 28 • 2:00 AM

Poverty and Geography: The Myth of Racial Segregation

Migration, regardless of race, ethnicity, gender, or sexuality (not to mention class), can be a poverty-buster.


August 27 • 4:00 PM

The ‘Non-Lethal’ Flash-Bang Grenades Used in Ferguson Can Actually Be Quite Lethal

A journalist says he was singed by a flash-bang fired by St. Louis County police trying to disperse a crowd, raising questions about how to use these military-style devices safely and appropriately.


August 27 • 2:00 PM

Do Better Looking People Have Better Personalities Too?

An experiment on users of the dating site OKCupid found that members judge both looks and personality by looks alone.


August 27 • 12:00 PM

Love Can Make You Stronger

A new study links oxytocin, the hormone most commonly associated with social bonding, and the one that your body produces during an orgasm, with muscle regeneration.


August 27 • 11:05 AM

Education, Interrupted

When it comes to educational access, young Syrian refugees are becoming a “lost generation.”


Follow us


Subscribe Now

Your Brain Decides Whether to Trust Someone in Milliseconds

We can determine trustworthiness even when we’re only subliminally aware of the other person.

Young, Undocumented, and Invisible

While young migrant workers struggle under poor working conditions, U.S. policy has done little to help.

Education, Interrupted

When it comes to educational access, young Syrian refugees are becoming a “lost generation.”

No, Smartphone-Loss Anxiety Disorder Isn’t Real

But people are anxious about losing their phones, even if they don’t do much to protect them.

Being a Couch Potato: Not So Bad After All?

For those who feel guilty about watching TV, a new study provides redemption.

The Big One

One in two full-time American fast-food workers' families are enrolled in public assistance programs, at a cost of $7 billion per year. July/August 2014 fast-food-big-one

Copyright © 2014 by Pacific Standard and The Miller-McCune Center for Research, Media, and Public Policy. All Rights Reserved.