Ever wondered how to know if your partner is cheating on you? Checking their text messages, stalking them on Facebook, rifling through receipts, or having that awkward conversation are no longer your only tactics in the fight for fidelity.
Scientists say it will be written all over their face. But only if they’re a man.
According to a new study male adulterers are unable to keep a poker face when it comes to sexual unfaithfulness, and even strangers can tell when they’ve been up to no good.
The findings, published in the Royal Society Open Science journal, found both men and women were able to predict with a significant level of accuracy which men were playing away from home just by looking at photos of them – but that women were utterly inscrutable.
The study found male cheats tended to have more masculine features – squarer chins, more prominent brows, angular jaws – and people inherently picked these people out of a line up.
Researchers from the University of Western Australia who led the study said humans may have developed the ability to pick out a philanderer because being able to spot an unfaithful male could have given ancient humans an evolutionary advantage. “Given the reproductive costs of being cheated on, evolutionary theories predict that it would be [beneficial] for individuals to evolve strategies to prevent sexual infidelity,” they said.
The researchers asked 1500 people to look at photographs of 200 men and women who had been questioned about their faithfulness and whether they’d tried to “poach” people outside of their relationship.
Participants were asked to rate the attractiveness of the people in the photographs and how feminine or masculine their facial features were. They were then asked to estimate the likelihood of the person in the picture having cheated on a partner or having tried to seduce someone else’s.
Both men and women were able to estimate faithfulness for men with a level of accuracy that was significantly better than chance alone – and 20% of the subjects had a solid ability to detect unreliable men.
However, women could not be read in the same way – perhaps, the researchers said, because a more feminine appearance did not correlate with unfaithfulness. They also said an evolutionary ability to identify female cheats has been stumped by the use of cosmetics to alter appearance. Make-up or break-up, it seems.