You will never view a handshake the same way again.
According to a new study, the firmness of people’s grip gives a fascinating insight into their sex lives.
Researchers looked at the upper body strength, primarily grip strength, and sexual behaviors of 4,000 men and women.
They found stronger men were more likely to be in long-term relationships, while stronger women were more likely to have higher numbers of sexual partners.
For men, the scientists from Washington State University believe this shows greater upper body strength is a ‘favorable natural selection trait’, making them a more attractive mate.
They say more research is needed to understand the connection in women.
Commenting on this finding, lead author and anthropologist Caroline Smith said: ‘People have assumptions about men’s sexual behavior and how that’s related to evolution.
‘Besides acquiring more sexual partners, establishing long-term relationships was likely also important for men in evolutionary history.’
A new major study into the sexuality of more than 4,000 people, has revealed that a firm handshake indicates higher body count for both men and women
In a similar vein, a previous study found that women who exercised more had a greater number of sexual partners.
Researcher Dr Lee Smith, of Anglia Ruskin University in Cambridge, said at the time that exercising regularly cuts depression and boosts confidence.
He explained: ‘We know that participation in physical activity increases self-esteem and it is possible that self-esteem is linked to increased confidence in engaging in sexual activity with new partners.’
In the recent study, Ms Smith and her advising professor – WSU evolutionary anthropologist Ed Hagen – analyzed data on 4,316 US adults obtained from the 2013–2014 National Health and Nutrition Examination Survey.
They primarily looked at grip strength, which is a common measure used to approximate upper body strength.
This was then compared to participants’ survey responses about their sexual behavior.
The scientists say the findings support an evolutionary theory of mating based on ‘provisioning’.
Since human babies require a lot of care and resources, particularly from women during pregnancy and lactation, men were more desirable as partners when they could provide meat through hunting, which for hundreds of thousands of years before the modern era required upper body strength.
The stronger human males, who also stuck around and helped provide more food resources to those children as they grew, also would better ensure their survival.
While there are theories for men’s strength in relation to reproductive success, there are not so many for women’s strength, in part because women are not often included in these types of studies.
There was not an obvious explanation in this study’s data why women with greater upper body strength also had greater number of lifetime partners.
The researchers controlled for many variables, including general health and testosterone levels, but the connection still held.
They did cite a few potential theories, including that it is due to ‘assortative mating,’ meaning physically stronger people tend to partner with each other more frequently.
It could also be that women who are physically stronger ‘require less male investment or feel like they can take more risks’.
Ultimately, they say that more studies involving women would be needed to uncover more evidence for the reasons behind this connection as well as ‘a better understanding of human evolution in general’.
‘I believe it’s important to continually test our theories, especially by expanding our research questions to include women,’ Ms Smith concluded.
