New research from Indiana University and Yale suggests that college-age men confuse friendly non-verbal cues with cues for sexual interest because the men have a less discerning eye than women -- but their female peers aren't far behind.

In the study, appearing in the April issue of the journal Psychological Science, men who viewed images of friendly women misidentified 12 percent of the images as sexually interested. Women mistook 8.7 percent of the friendly images for sexual interest.

Both men and women were even more likely to do the opposite -- when viewing images of sexually interested women, men mistakenly called 37.8 percent of the images "friendly." Women mistook 31.9 percent of the sexual interest cues for friendliness.

Scientist have long known that young men are more likely than women to confuse friendly non-verbal cues with cues for sexual interest but the explanation for the gender difference has been less clear. The more popular of two competing theories attributes this to a tendency by young men to over-sexualize their social environment. The less popular theory -- and the one supported by this new study -- claims that women have an advantage when it comes to interpreting facial expressions and body language expressing a variety of emotions, thus are more likely to accurately ID cues for sexual interest. Young men are simply less literate when it comes to non-verbal cues.

"Relative to women, men did not oversexualize the image set in our study," said lead author Coreen Farris, a doctoral student in the Department of Psychological and Brain Sciences at IU Bloomington. "Both men and women were reluctant to state that ambiguous cues were 'sexual interest.' In fact, men and women utilized nearly identical thresholds for the degree of sexual interest that must be perceived before they were willing to go out on a limb and state that the nonverbal cues were sexual in nature."

Farris said it is interesting that their study found no evidence to support the first theory.

"In many ways, the results point to a more general explanation for why young men make the decisions they make," she said. "The observed advantage among women in ability to discriminate between friendliness and sexual interest extends to processing of sad and rejecting cues. This suggests that the increased tendency among young men to incorrectly read sexual interest rather than friendliness may simply be an extension of a general disadvantage in reading nonverbal cues, rather than a process unique to sexual signaling."

The study involved 280 heterosexual college-age men and women, average age of 19.6. Seated in a private computer room, the men and women each categorized 280 photo images of women (full body, fully clothed) into one of four categories -- friendly, sexually interested, sad or rejecting. Images were selected for each of the categories based on an extensive validation process.

The study found that both men and women were least accurate at correctly identifying the photos indicating sexual interest. Farris, whose research focuses on sexual aggression in men, noted that the results reflect average differences.

"The data don't support the idea that all men are bad at this or that all women are great at this," she said. "It's a small difference."

The authors wrote in Psychological Science that in most cases, the "negative consequences of sexual misperception will not extend beyond minor social discomfort." However, among a small group of men, sexual misperception is linked to sexual coercion, and thus, is an important process to understand in order to improve rape prevention efforts on university campuses. Farris said studies such as this should help establish a better understanding and a baseline for young men's perceptions of sexual intent and contribute to efforts aimed at preventing sexual aggression.

Coauthors are Teresa A. Treat, associate professor in the Department of Psychology at Yale University; Richard J. Viken, professor in the Department of Psychological and Brain Sciences at IU Bloomington; and Richard M. McFall, professor emeritus in the Department of Psychological and Brian Sciences at IU Bloomington.