Revisiting Female Short-term Mating Strategy & Infidelity

Why do women cheat on their partners?

A long-standing hypothesis in evolutionary psychology asserted that women seek extra-pair copulations (infidelity) in order to secure resources from another man or acquire good genes from him for potential offspring.

But do women really seek better genes from another man?  That part of the female “short-term mating strategy” has come into question.

New Statistics for Non-paternity

New data from DNA fingerprinting technology suggests only 2-3% of children come from men other than the husband or primary partner.  It appears women get genes and investment from exactly the same guy — their primary partner.

While the female short-term mating strategy may still feature acquisition of additional resources, there are other clues to explain the infidelity of women as reported by evolutionary psychologist David Buss.

Buss cites these clues:

1. Women who are sexually or emotionally unhappy have affairs.
   This is not true for men. Men do not often report marital unhappiness as a reason for an affair. According to Buss, men can be relatively happy in their marriage and still have affairs. There is no difference in marital or sexual happiness between men who have affairs and men who do not. The issue of emotional dissatisfaction appears to be specific to women.
2. 70% of women become emotionally involved with or fall in love with their affair partner.
   In contrast, only about 30% of men do.
3. The qualities desired by women in an affair partner are identical, or nearly identical, to qualities desired in a long-term mate.
   This is not true for men. For example, women usually want intelligence in an affair partner. For men, intelligence in an affair partner is mostly irrelevant.

Desiring the same qualities in an affair partner further supports the view that the female long-term mating strategy is significantly more adaptive in evolution than the short-term mating strategy.  (See background notes below.)

So, what may be driving a woman to have an affair?

New research posits a different matrix of motivations, called the “mate switching hypothesis.”  Women have affairs, in part, to switch mates.

Preparing for “the Switch” — Partner Insurance

David Buss and Cindy Meston report (Why Women Have Sex) that women have affairs to test the waters to see if there is someone better out there for them, to attempt to “trade-up” for a better partner.  Women have affairs if they think their relationship may be dissolving.  And women cultivate “back-up mates.”  As Buss likes to joke in quoting a female research participant, “men are like soup; you always want to have some on the back burner.”  (See page: Why Women Have Sex.)

Nicole Wedberg’s research on heterosexual women while at SUNY New Paltz called this “partner insurance” – the cultivation of a back-up boyfriend, or “Mr. Plan B.”  Wedberg found that 20% of women in committed relationships will report having a Mr. Plan B.  One of the predictors included low relationship satisfaction.  Wedberg builds on the work of Dibble et al (2015) that found college women have on average 3.78 Plan Bs.*

Returning to Clue #1

Women unhappy in their current relationship may cheat in order to feel alive and expand their sense of self, says Esther Perel in State of Affairs.   Affairs are seen as acts of rebellion or bursts of freedom that release constraints. In Perel’s words, an emotionally dissatisfied woman “is not looking for another person as much as looking for another self.”  Yet, another person who demonstrates a desire for a woman is a powerful new elixir for self-esteem.  Affairs magnify the difference between being loved and being wanted.

Even in a search for a “new self,” the motivation to switch mates is easily triggered if there is sexual and emotional unhappiness.  Female choice in mate selection is the most powerful force on the planet.  What on the stove?  Partner insurance.  Tasty and willing Mr. Plan B.  Soups on.  Make the switch?

Post-script and Background Notes

The predominant theory in evolutionary psychology suggests humans have both long-term and short-term mating strategies that operate as concurrent functions sensitive to context and environmental conditions.

Women’s long-term mating strategy is a more predominant evolutionary adaptation than is their short-term strategy; it is driven by genetic characteristics and interests of our species: internal fertilization, an extended period of gestation, prolonged infant dependence on mother’s milk, and the need for relatively “high” male parental investment (compared to other primates).   A woman’s long-term strategy seeks protection and a provision of resources from a mate.  It also seeks character traits that ensure stability and loyalty to her and her children over the long-term.

As an evolutionary adaptation, men’s short-term mating strategy seeks more immediate sexual access to a variety of partners.  This view has not changed among evolutionary psychologists.  Research clearly supports the view that men seek more sexual partners than women.

Tension Between Preference for Resources and Character

This blog post reconsiders and updates the “dual hypothesis” for the female short-term mating strategy: seeking resources and/or genes from a partner other than the primary partner.

But what is more salient in mate selection and relationship satisfaction is the tension between two preferences INSIDE the female long-term strategy:  resources and character.   Resources and character are often dueling, competing preferences that necessitate trade-offs and compromise for most women in choosing a mate.

We know that men still commit infidelity more than women, although women seem to be closing the gap in modern times.  The reasons for this run a gamut of psychological, sociological, cultural, and economic issues.  Switching mates appears to be one adaptive strategy in response to the changing rules of heterosexual partnership.

*Dibble, et al (2015, June 11).  Simmering on the back burner:  communication with and disclosure of relationship alternatives.   Communication Quarterly, 63(3), 329-344.

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