Onur Guentuerkuen of Ruhr-University Bochum in Bochum, Germany, reports that he spied on 124 pairs of adults who turned their heads left or right while kissing on the lips in public places in Germany, Turkey and the United States. Two-thirds of the kissers went to the right, he found.
Prior research has found that babies also tend to turn their heads to the right rather than the left during their final weeks of gestation and for the first six months after birth, Guentuerkuen says in Thursday's issue of the journal Nature.
So the results on kissing show that early head-turning bias may affect behavior in adulthood, he says. People also prefer to use the right foot, ear and eye by about two-to-one, suggesting those behavioral biases may be related, he said.
But right-handedness dominates the population far more, about eight-to-one, so that's either not related or it's affected by cultural influence, he said.
The researcher watched kissing couples in airports, railroad stations, beaches and parks. He estimated their ages at around 13 to around 70.