Recently, couples across the globe participated in a kiss and tell for the sake of science. The results of the study, which were originally reported in the scientific journal Nature, showed that across gender, geography, and age, couples have at least one natural predilection to kissing that's seemingly universal. The data from the study shows that we favor turning our heads to the right before locking lips. So naturally, scientists wanted to figure out how we ended up so directionally biased, how we've been influenced to kiss the way that we do, and what it could mean about our physical instincts.
Originally, the study was inspired by the perceived Western tendency to turn the head to the right before engaging in a kiss. But because we're used to seeing kissing on TV, in the movies, in front of us at bars, on the streets and in our homes, it's hard to say whether art is imitating life or vice versa here. Kissing is incredibly normalized and common. So, for the sake of retrieving dynamic and telling results, scientists set out to find heterosexual couples to study across the globe — the goal being to find people living in non-Western countries, who didn't share the same cultural norms. This way, they could better isolate the tendency as human nature and not societal influence.
Using 48 Bangladeshi heterosexual married couples, the study investigated the head-turning bias in two ways. The data included inclinations for both kiss initiators and kiss recipients, sex and handedness. To increase the opportunity for authenticity, scientists had the couples go off in a private room to kiss, as in Muslim culture, kissing is a private act that's not nearly as commonly seen as it is in the Western world. Then, scientists interviewed each participant separately about what happened. The results showed that men were 15 times more likely to initiate the kiss, and that more than two thirds of couples chose to turn their head to the right before kissing. The study also showed that people were more likely to lean to the side that they are most dexterous, but that if a lefty leaned to the left before kissing, a righty would adjust and lean to the left, too. Likely, this is to avoid awkwardness — because there's nothing weirder than jerking your head around as someone is moving their face towards yours, romantically.
So according to the results, when non-Western couples kiss in private, assuming they are less likely to be ruled by cultural norms, they still favored the right side — which could imply that we are neurologically wired to do so. One reason our neurophysiological inclination might be to turn our head to the right before kissing is because the brain separates tasks for its different hemispheres. If you're a righty, your brain is going to favor the clockwise direction, and tasks that are carried out on the right side — a job that's directed from the left cerebral hemisphere, which is also the part of the brain that controls emotion an decision making. Considering the fact that lefties only make up about 10 percent of the population, it's easy to understand why the vast majority of people are leaning to the right.
As for why men were much more likely to initiate a kiss? Societal and cultural norms aside, the study shows that testosterone might have something to do with it. Testosterone is the hormone that makes you sexually dominant and motivated, so when men and women are face-to-face, their testosterone levels can rise, and if the male already has a higher level of testosterone, this interaction is going to make them more likely to initiate a kiss. But it's pretty clear that biology aside, societal and cultural norms are ever-changing, so like any other studied behavior, interactions will depend on the couple more than the "norm". Hopefully studies like this will encourage researchers to study a more diverse mix of sexualities and cultures to better represent LGBTQ+ people and the population at large, and we can get a much broader, representative sense for what is and isn't biologically wired in us when we lean in for a kiss.