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

August 26 • 4:00 PM

Marching in Sync May Increase Aggression

Another danger of militarizing the police: Marching in lock step doesn’t just intimidate opponents. It impacts the mindset of the marchers.


August 26 • 3:03 PM

The Best Reporting on the Federal Push to Militarize Local Police With Riot Gear, Armored Vehicles, and Assault Rifles

A few facts you might have missed about the flow of military equipment and tactics to local law enforcement.


August 26 • 2:00 PM

How the Other 23 Percent Live

Almost one-fourth of all children in the United States are now living in poverty, an increase of three million kids since 2005.


August 26 • 12:00 PM

Why Sports Need Randomness

Noah Davis talks to David Sally, one of the authors of The Numbers Game: Why Everything You Know About Soccer Is Wrong, about how uncertainty affects and enhances the games we watch.


August 26 • 10:00 AM

Honor: The Cause of—and Solution to—All of Society’s Problems

Recent research on honor culture, associated with the American South and characterized by the need to retaliate against any perceived improper conduct, goes way beyond conventional situations involving disputes and aggression.



August 26 • 8:00 AM

The Transformative Effects of Bearing Witness

How witnessing inmate executions affects those who watch, and how having an audience present can also affect capital punishment process and policy.



August 26 • 7:15 AM

Being a Couch Potato: Not So Bad After All?

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


August 26 • 6:00 AM

Redesigning Birth Control in the Developing World

How single-use injectable contraceptives could change family planning in Africa.


August 26 • 4:15 AM

How Gay Men Feel About Aging

Coming to terms with growing old can be difficult in the gay community. But middle-aged men are inventing new strategies to cope.


August 25 • 4:00 PM

What to Look for In Dueling Autopsies of Michael Brown

The postmortem by Michael Baden is only the beginning as teams of specialists study the body of an 18-year-old African American killed by police in Ferguson, Missouri.


August 25 • 2:00 PM

Thoughts That Can’t Be Thought and Ideas That Can’t Be Formed: The Promise of Smart Drugs

Are we asking the right questions about smart drugs? Marek Kohn looks at what they can do for us—and what they can’t.


August 25 • 12:00 PM

Does Randomness Actually Exist?

Our human minds are incapable of truly answering that question.


August 25 • 10:31 AM

Cesareans Are Still Best for Feet-First Babies

A new study confirms that surgery is the safest way to deliver a breech fetus.


August 25 • 10:00 AM

What Can Hurricanes Teach Us About Socioeconomic Mobility?

Hurricane Katrina wrought havoc on New Orleans but, nine years later, is there a silver lining to be found?


August 25 • 8:00 AM

How Low Voter Turnout Helps Public Employees

To a surprising degree, as voter turnout goes down, public employee compensation goes up.


August 25 • 6:00 AM

Beyoncé Isn’t an Anti-Feminist Terrorist

A new book called Staging the Blues shows she’s embracing a tradition of multi-dimensional stardom, rather than one racist trope.


August 25 • 4:00 AM

A Tale of Two Abortion Wars

While pro-life activists fight to rescue IVF embryos from the freezer, pregnant women in their third trimester with catastrophic fetal anomalies have nowhere to turn.


August 22 • 4:00 PM

The Invention of the Illegal Immigrant

It’s only fairly recently that we started to use the term that’s so popular right now.



August 22 • 2:00 PM

What Can U.S. Health Care Learn From the Ebola Outbreak?

A conversation with Jeanine Thomas, patient advocate, active member of ProPublica’s Patient Harm Facebook Community, and founder and president of the MRSA Survivors Network.


August 22 • 1:22 PM

Two Executions and the Unity of Mourning

The recent deaths of Michael Brown and James Foley, while worlds apart, are both emblematic of the necessity for all of us to fight to uphold the sanctity of human dignity and its enduring story.


August 22 • 10:00 AM

Turbo Paul: Art Thief Turned Art Crime Ombudsman

There’s art theft, there’s law enforcement, and, somewhere in between, there’s Turbo Paul.


August 22 • 8:00 AM

When Climate Change Denial Refutes Itself

The world is warming—and record-cold winters are just another symptom.


Follow us


Subscribe Now

Being a Couch Potato: Not So Bad After All?

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

How Gay Men Feel About Aging

Coming to terms with growing old can be difficult in the gay community. But middle-aged men are inventing new strategies to cope.

Cesareans Are Still Best for Feet-First Babies

A new study confirms that surgery is the safest way to deliver a breech fetus.

The Impossibility of the Night Shift

Many night workers get “shift-work sleep disorder.” And no one knows how to treat it.

How the Brains of Risk-Taking Teens Work

There's heightened functional connectivity between the brain's emotion regulator and reason center, according to a recent neuroscience paper.

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.