Dig if you will the picture: two people engaged in a kiss. Prince sang about "curious poses," but new research suggests that most of us may strike similar poses, leaning to the right instead of the left when kissing the lips of our partners. Researchers at the University of Bath and in Bangladesh report in the journal Scientific Reports that more than two-thirds of so-called kiss "initiators" and kiss "recipients" in their study leaned their heads to the right, with a person's handedness predicting which way the initiator went. That didn't hold for the recipients, however, who preferred to match the direction of the head leaning toward them and avoid what was described as discomfort when heads were mirrored.
For this study, researchers looked at 48 married couples in Bangladesh, where kissing is rarely done in public or on screen, who reported on kissing in the privacy of their own homes. The findings are similar to those found in previous studies in Western countries, where kissing is often more public—suggesting the reason may be innate instead of cultural. The results suggest that kissing is determined by how the brain assigns tasks to its left and right hemispheres, with certain tasks playing out in the left, more emotion-based half of the brain, reports the Guardian. Hormone levels like testosterone may be unevenly distributed as well, spurring a right-leaning bias. Phys.org notes that men initiate kisses 15 times more frequently than women, and that this tendency to lean to the right could have wider implications for cognitive science and neuroscience. (Why do humans kiss, anyway?)