A study led by scientists at the University of Pretoria in South Africa and published in the November 27 issue of the journal Proceedings of the Royal Society B. Nor repels the long-known myth according to which macho features are what a woman is more attracted by in men.
Scientists say that the macho aspect has long been related with a healthy body and a good functioning of the immune system.
However, they discovered that not masculine facial features such as a powerful jaw or a sharp gaze is what determines a male's health or attractiveness, but the weight of his body, Lice Science reports.
In an attempt to determine the role of the body fat in a man's immune system's functioning as well and is his attractiveness to women, researchers have made an experiment.
First, they had 69 Caucasian males photographed in underwear. They also had the men's body fat and testosterone level measured, and their immune system's response registered.
Afterwards, the men were given a vaccine for hepatitis B. It was observed that the bodies with a strong immune system response released a higher amount of antidotes than the one whose response was weaker.
Then, 29 heterosexual Latvian women in the fertile state of their menstrual cycles were asked to look at the picture and state the men's attractiveness level.
Meanwhile, 20 Finnish men and women were asked to determine the men's manhood and other 14 Latvian women – to state their facial fatness.
The experiment revealed that dumpy men were both unattractive and unhealthy. Surprisingly, it was proved that masculinity wasn't related to any of the above features.
“We found that a man’s weight serves as a better indicator of the relationship between immune response and attractiveness than masculinity does,” said Vinet Coetzee, researcher at the University of Pretoria.
“It is therefore more likely that Latvian women use weight, rather than masculinity, in their subconscious judgments of a man’s immunity.”
Researchers admit that there might be some gaps in the accuracy of the study, because of the complexity of the immune system's measures, which has not been taken into account.
However, it “serves as a stepping stone for future studies that could test this relationship in different populations using alternative measures of immunity,” Coetzee said.