Women are able to subconsciously pick up cues in men's faces and use those cues to determine if they are attracted to the males for long-term or short-term relationships, according to a new study conducted by researchers at the University of California, Santa Barbara and the University of Chicago.
The study was published online today by the Proceedings of the Royal Society of London, the UK's national academy of science.
Men whose faces reflected an interest in children were intuitively perceived by woman as candidates for long-term commitments, whereas men whose faces indicated high testosterone levels were determined to be short-term prospects for relationships.
"Women are surprisingly accurate in being able to determine interest in children and testosterone levels," said James Roney, assistant professor of psychology at the University of California, Santa Barbara, who is the lead author of the paper. "Our data suggest that men's interest in children predicts their long-term mate attractiveness even after we account for how physically attractive the women rated the men," he said.
For the study, the researchers recruited male undergraduate students from a variety of ethnic backgrounds who were tested for testosterone and for their interest in children.
Researchers took saliva samples to measure testosterone levels. To determine interest in children, researchers showed the men a pair of pictures, one each of an adult and a baby. They were then asked which picture they preferred. Slightly more than twelve percent of the men expressed no interest in the baby pictures, while the rest expressed a range of interest, up to nine out of ten preferences for the infants.
The researchers then took pictures of each man, asking them to display a neutral expression. An oval frame was placed around each photo to focus attention on the faces and the photos were shown to undergraduate women from diverse backgrounds at UCSB.
The women were asked to rate the men according to whether they thought the men liked children, whether they appeared masculine, physically attractive, or kind. They were then asked to determine men's attractiveness as short-term romantic partners or as long-term partners for relationships such as marriage.
The men chosen as being most interested in children were also the same men who had expressed the most interest in children in the photo test. The women were also able to determine from their photos which men had high testosterone levels because they perceived the men as looking masculine.
Although women said they were attracted to the men who tested high for testosterone, an important factor in their attraction to men for a long-term relationship was their perception of a man's affinity for children, even after accounting for their perceptions of men's general kindness.
"The research suggests that men's interest in children may be a relatively under-appreciated influence on men's long-term mate attractiveness," Roney said.
Source: University of California, Santa Barbara
Explore further: Teen drivers a danger to others on the road, report warns