Researchers at the University of Western Australia collected 101 images of Caucasian men and 88 images of Caucasian women who had either cheated on their partners in the past, engaged in "poaching" behavior by attempting to lure someone else's partner or who had remained loyal at some point in their lives.
The researchers then asked 1,500 heterosexual, white adults to give each photograph a ranking on a scale from one to 10, where one is "not at all likely to be unfaithful" and 10 is "extremely likely" to be unfaithful. The participants were also asked to indicate how attractive, trustworthy or masculine or feminine the people in the photos seemed to be based on their physical appearances.
The results were quite interesting.
Men and women are able to correctly predict whether a man had cheated in the past. However, both male and female participants had a hard time correctly predicting a woman's infidelity.
"Taken together, both men and women showed above-chance accuracy for men's faces but not women's faces. Therefore, perceived unfaithfulness may indeed contain some kernel of truth in male faces," the researchers wrote in their study.
The study also found that men with more masculine features were not only more likely to have cheated, but were also more likely to be perceived as a cheater by the participants.
"Sexual dimorphism, particularly male masculinity, is positively related to preference for uncommitted sex and multiple matings," the study states.
"For men's faces, masculinity mediated the relationship between perceived unfaithfulness rated by women and actual unfaithfulness, indicating that women used the valid cue of masculinity to assess men's sexual unfaithfulness at above-chance levels. For women's faces, even though attractiveness and femininity were related to perceived infidelity, neither cue was related to actual infidelity. Therefore, it remains unclear what cues might be driving accuracy in men's judgements of women's unfaithfulness," the study adds.
However, despite the findings, researchers warn against relying too heavily on first impressions.
"If we are to rely solely on our first impressions to detect cheaters/poachers, then we will make substantial errors," Yong Zhi Foo, one of the authors of the study, told AFP Wednesday. "Our results must not be taken to mean that first impressions can be used in any everyday situations."