You can tell a lot about a person by just looking at their face— their age, their gender, & even their emotional state. Now, researchers at Nipissing University in Canada, say facial features can also show a person's $ex drive & how likely they are to cheat in relationships.

The study, published in Archives of $exual Behavior, found that both men & women with shorter, wider faces were more $exually motivated, meaning they have higher libidos. Men with extremely wide faces (calculated as facial width-to-height ratio, or FWHR) had a higher $ex drive than others & were more open to casual $ex that does not involve love or commitment. They as well considered being unfaithful to their partners.

"Together, these findings suggest that facial characteristics might convey vital info about human $exual motivations," Steven Arnocky, lead author of the study, said in a statement.

Arnocky & his colleagues already knew that the size of a person's face are linked to certain psychological & behavioral traits. For instance, a 2014 study published in Psychological Science discovered that women perceived men with wider faces as more dominant & more attractive within 3 minutes of face-to-face speed dating. The women saw a high FWHR as more dominant & having more romantic potential, but only for short-term relationships.

That finding prompted the researchers to investigate whether FWHR could predict $ex drive among both men & women. In 2 separate studies, Arnocky, a psychologist focused on $ex & human behavior, examined correlations between $exuality & facial features. In the first study, 145 male & female undergraduate students in romantic relationships were asked questions concerning their interpersonal behavior & $ex drive, & their FWHR was measured using photographs. In the second study, an extended version of the first, 314 students answered extra questions about socio$exual orientation (attitudes toward casual $ex, for example) & intended infidelity.

According to their report, FWHR was considerably correlated with $ex drive. Just by knowing an individual's FWHR, the researchers could guess what that person reported about their $ex drive. The link held true for both genders.

Researchers believe these FWHR-associated behaviors can be explained by $ex hormones, particularly testosterone. Men & women's $exual motives & behavior are partially modulated by testosterone. During puberty, testosterone is linked to later $exual motives & behavior in men & women. For example, a 2011 study published in Hormones & Behavior found both partnered men & women who reported either a greater desire for casual $ex or $exual behavior had testosterone levels that were comparable to their single counterparts. Single men & women are known to have higher testosterone compared to those who are partnered up.

Arnocky's study could incite further research on whether the effects of FWHR can be detected in adolescence & whether they remain all through adulthood. If this correlation holds through later adulthood, the link could provide insights on long-term relationships among older adults.

To cut the long story short,  a person’s $exual preferences could actually be written all over their face.