A new study suggests that straight women don't necessarily prefer masculine, strong-jawed men as much as they prefer trim ones. Why? It's a sign of good genes, researchers say.
Researchers from the University of Pretoria in South Africa say that while their research does confirm that women are attracted to macho male features, what is more important is that the men are lean as opposed to pudgy or very thin when assessing physical attractiveness. Men at a healthy weight are considered to have stronger immune systems and better overall health, suggests study researcher Vinet Coetzee.
To reach their conclusions, Coetzee and his colleagues took photos of 69 Caucasian male volunteers in their underwear, while taking measurements of their body fat and testosterone levels. Among the subjects, 65 percent were at a healthy weight, four percent were underweight and 30.4 percent were overweight or obese. The subjects then took an immune system response test, using a vaccine for hepatitis B, to reveal which men had weaker immune systems.
Nearly 30 Latvian women -- all heterosexual and in fertile periods of their menstrual cycles -- looked at the photographs, judging them on attractiveness. A separate group of 20 heterosexual Finnish men and women also judged the men for masculinity, while an additional 14 Latvian women rated the men on their levels of facial fatness, which relates to overall body fatness, the researchers said.
Results showed that men with fatter faces were seen as less appealing to fertile women, and were shown to have weaker immune systems.
"We found that a man's weight serves as a better indicator of the relationship between immune response and attractiveness than masculinity does," Coetzee told LiveScience. "It is therefore more likely that Latvian women use weight, rather than masculinity, in their subconscious judgments of a man's immunity."
The findings were published Wednesday in the journal Proceedings of the Royal Society B.
LiveScience points to a separate study from the University of Nottingham in Malaysia that finds that men with a "golden" skin tone may be more attractive to women. The findings were published in the January 2012 issue of the journal Evolution and Human Behavior.
Access the new study: http://rspb.royalsocietypublishing.org/content/280/1751/20122495.full