I discussed the left-sided bias for infant cradling in my last blog post (February 3, 2021). When I advertised the post to left-hander Facebook groups, I received comments from left-handed mothers saying they held babies on the right side, not the left, to free their preferred hand while cuddling an infant. These comments reveal a classic problem when investigating side preferences in human behaviors. Is the bias related to a person’s preferred hand or not?
A similar issue arises when studying two other forms of social touching, hugging and kissing. Individuals show a hugging side preference when they lead with the same arm to hug by placing it around another person’s neck. Similarly, one sees side preference in kissing when a person habitually leans the head to one side when initiating a kiss of another person. Studies indicate side biases in hugs and kisses and researchers have asked, once again, the same question. Are side biases in social touch situations predicted by a person’s handedness?
Researchers explore side biases in hugging and kissing by conducting studies in both natural and laboratory settings. One research group observed individuals embracing in an arrivals area of an airport. They found an overall rightward bias (leading with the right arm to hug) in most situations although male-to-male hugging did not show the distinct rightward preference found in female-to-female and female-to-male embraces. Other studies done in airport settings confirm an overall right arm hugging bias with 83% of people showing right-sided embraces.¹
Field studies in natural settings do not permit researchers to assess whether the observed right-side bias is related to handedness. For this reason, laboratory experiments are necessary. A recent study used 100 young adults, both male and female, as participants. Their handedness was measured and then they were asked to hug two full-size mannequins, one resembling a male and one a female. Each participant completed the hugs multiple times. Most of the participants were right-handed (89%) but those who had left-handed scores also showed a leftward hugging preference.²
Kissing sidedness has also been studied in natural settings such as parks, airports and beaches. Under these conditions, researchers report that 65% of those observed show a preference for a rightward kissing posture. The laboratory study described above also looked at side preferences when kissing. The participants were asked to kiss two inanimate heads, one male and one female, multiple times. This study did not find a relationship between kissing side preference and participants’ handedness scores.
Overall, the research results are mixed. Observations in natural settings indicate a right-sided bias for both hugs and kisses. However, most people are right-handed and, when handedness is not measured, the result likely favors the right-handed majority. Laboratory studies, where handedness is assessed, indicate that hugging may be related to handedness…left-handers lead with the left arm over the shoulder while right-handers lead with the right arm. A consistent kissing bias related to handedness side has not been verified by recent laboratory research. Other factors, such as whether the social touch situation is under joyful, neutral or sad circumstances and the gender combination of the participants (same sex or opposite sex), also seem to affect a hugging and kissing side bias.
¹Ocklenburg, S., Packheiser, J., Schmitz, J., Rook, N., Güntürkün, O., Peterbrus, J., & Grimshaw, G.M. (2018). Hugs and kisses-The role of motor preferences and emotional lateralization for hemispheric asymmetries in human touch. Neuroscience and Biobehavioral Reviews, 95, 353-360. https://doi.org/10.1016/j.neubiorev.2018.10.007
²Packheiser, J. Schmitz, J., Metzen, D., Reinke, P., Radtke, F., Friedrich, P., Güntürkün, O. Peterburs, J., & Ocklenburg, S. (2020). Asymmetries in social touch-motor and emotional biases on lateral preferences in embracing, cradling and kissing. Laterality: Asymmetries of Brain, Behaviour, and Cognition, 25, 325-346. https://doi.org/10.1080/1357650X.2019.1690496