The Voice of a Cheater

Can you tell if someone has been unfaithful by the sound of their voice alone?

Long-term monogamy is considered by many of us to be the ideal form of relationship. However, research shows that a majority find it difficult to stick to one partner. Both men and women prefer to pair up with someone who is less inclined to cheat. But can we judge whether a potential partner has ever cheated?

Two psychologists from the US recently attempted to answer this question. Susan Hughes and Marissa Harrison recorded men and women reading the numbers 1 to 10. Half of these volunteers admitted to having sex with someone other than their primary partner; the other half of the volunteers protested their innocence. If we assume that everyone was telling the truth, Hughes and Harrison now had a set of voice recordings of cheaters and non-cheaters.

Can a microphone be an accurate cheater-detection device? LaVladina/Flickr

Next, a second group of volunteers listened to the voice recordings. They rated the likelihood that each speaker had cheated on their partner. The volunteers used a 10 point scale, where 1 = not at all likely to cheat and 10 = very likely to cheat.

The results of the study showed that cheaters were more likely than non-cheaters to be suspected of infidelity. Based on voice alone, the volunteers identified cheaters and non-cheaters.

You may be wondering if the cheaters and non-cheaters differed in some other way than their past infidelity. For example, perhaps attractive people are more likely to cheat because they have more opportunities. If this is true, it could be that the listeners are making an attractiveness judgment. But this is unlikely to be a problem here because the researchers controlled for the attractiveness of their speakers. The cheater and non-cheater groups included people who matched on vocal attractiveness, voice pitch, height, weight, body shape, and various aspects of sexual experience such as total number of sex partners. Listeners are clearly basing their judgments on something else. But what?

Hughes and Harrison speculate that it could be down to characteristics of speech they did not measure. For example, masculine men, who are more likely to cheat, tend to speak with less clarity than more feminine men. Extroverts — also more likely to cheat — speak with fewer pauses and vary their voice pitch more frequently.

So it remains unclear how we detect infidelity from speech. What we do know is that a cheater’s voice tells a tale their partner may not wish to hear.

Hughes, S. M., & Harrison, M. A. (2017). Your cheatin’ voice will tell on you: Detection of past infidelity from voice. Evolutionary Psychology, 15(2), 1474704917711513. Read paper

For an audio version of this story, see the 29 August 2017 episode of The Psychology of Attractiveness Podcast.

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