Our bodies are remarkable things. All day long, they keep our hearts pumping and our lungs filling with air. They do all this without any instruction from us. But they do other things, too—things we don’t even realize we’re doing. Take, for example, a new study published in Nature Scientific Reports that finds people subconsciously tilt their head toward their dominant side when leaning in for a kiss.
We call this dominance right- or left-handedness, but it actually runs through our entire body, including the direction we automatically turn our heads. For most people, that means looking to the right.
"Head turning is one of the earliest biases seen in development," lead author Rezaul Karim of the University of Dhaka said in a statement. "Even in the womb, a preference for turning the head to the right is observable before that of favoring the right hand or foot. Whether this fundamental bias is innate and extends into adulthood is a lingering question for neuroscience and psychology."
One way to find out is by watching people kiss. Numerous experiments have been conducted to determine which way people tilt their heads, and they have concluded that we lean to our dominant side. But those experiments all took place in Western countries, and they were either conducted in public places like airports or in a lab—hardly places where participants might feel at home.
To test the premise in a more comfortable setting, Karim and his colleagues recruited 51 married couples in Bangladesh and invited them to start keeping track of their kisses in the privacy of their homes. Each participant received two questionnaires: one to determine their dominant side and another to record their head-tilt tendencies during kissing.
The results looked quite similar to those of earlier studies elsewhere in the world. When initiating a kiss, most people leaned right, but lefties turned left.
Things looked slightly different on the receiving end of a smooch. Regardless of their dominant hand, kiss-ees were most likely to tilt their heads in the opposite direction as their partners’, because, as we all know (and the questionnaires confirmed), it feels weird to go the other way.
Commonsense though they may seem, these findings do still need to be validated with more research. The in-home kissing experiment was one very small study among one very specific group of people, many of whom were friends of the researchers.
But co-author Michael Proulx of the University of Bath in the UK said the private nature of the experiment allowed participants to act naturally, and that the results of this natural behavior have "…implications for all people. Prior works could not rule out cultural learning due to having Western samples," he said. "It turns out, we as humans are similar even if our social values differ."