Infidelity: A Practitioner’s Guide to Working With Couples

Interview with Dr. Helen Fisher
Eds. Paul R Peluso and Taylor J. Irvine

Eds: On the topic of infidelity, what is the question that interests you the most?

Helen Fisher: The single most interesting piece of data that I’ve ever found came out of an academic paper in 1985.1 The scientists reported that 56% of men and 34% of women in their study were unfaithful to their partner, yet they were in long-term happy partnerships. That’s a revealing data point. Apparently, people sleep around—even when they are in really happy relationships. It made me wonder whether humanity has evolved a predisposition to philander for Darwinian evolutionary reasons.

Psychologists have dozens of theories about why people cheat. Boredom; poor communication; relationship dissatisfaction; opportunity; to solve a sex problem or have more sex; to feel more appreciated; for adventure; due to issues in their childhood; or feelings of entitlement (as when one partner makes more money, is better looking, or has a better education or background), or just because they want to get caught and terminate their relationship: there are hundreds of reasons that people say they are unfaithful.

“… adultery is so prevalent everywhere in the world.”

But this doesn’t explain why happily partnered people cheat and why adultery is so prevalent everywhere in the world—from those in hunter-gathering cultures to those who farm, herd, or live in postindustrial societies. Psychologists offer all kinds of cultural and psychological reasons for philandering. They’re all good. But could there be an underlying biological component as well? That’s what interests me.

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