According to a 2012 study, women are likely to gauge correctly when a man is unfaithful.
34 men and 34 women participated in the study and were asked to score the faithfulness of 189 Caucasian adults from their pictures.
The researchers found that the female participants were better able to distinguish between those who were faithful and those who weren't when they compared their responses to the 189 people's self-reported sexual histories.
They noted in the paper," We provide the first evidence that faithfulness judgments, based solely on facial appearance, have a kernel of truth."
According to a study that was published in the journal Biology Letters, Men, didn't seem to know anything. The researchers discovered that men frequently assumed attractive, feminine women were unfaithful.
Women, on the other hand, based their judgment on how masculine - not attractive the men looked.
The conclusion of this study is in relationships, women are more likely to know when their partners are unfaithful than men.