Seven Surprising Ways Brain Asymmetries Affect Your Daily Life
There are many subtle ways how brain asymmetries affect your behavior.
About 10 percent of people are left-handers, while about 90 percent are right-handers. Pretty much anybody knows whether they are left-handed, right-handed, or (in very rare cases) ambidextrous. Handedness is determined by our brains. The left part of the brain controls the right part of the body, while the right part of the brain controls the left part of the body. In left-handers, the motor areas on the right side of the brain are dominant for activities that require a high level of motor skills such as writing. Interestingly, handedness is not the only example of how such brain asymmetries affect our everyday lives. Here is a list of seven surprising ways brain asymmetries our everyday lives.
1. In addition to handedness, there is also footedness
While most people are aware of whether they are left- or right-handed, fewer people think about whether they are left- or right-footed. A recent large-scale meta-analysis (Packheiser et al., 2020) reported that about 12.1 percent of people are left-footed. There was a large overlap with handedness, but it was not 100 percent perfect. While only 3.2 percent of right-handers were left-footed, about 60.1 percent of left-handers were left-footed. Thus, the chance of being left-footed is considerably higher for a left-hander than for a right-hander.
2. We have a favorite side for hugging
When we embrace someone else, we typically lead the hug with one arm. A recent study (in which I was part of the research team) analyzed whether people preferentially hug with their left or their right arm (Packheiser et al., 2019). In the study, hugging couples were observed at the arrivals or departure lounges at international airports. Moreover, videos of people who blindfold themselves and let strangers hug them on the street were analyzed.
Overall, people preferred to use their right arm for hugging. In the emotionally neutral situation in which strangers hugged a blindfolded person, 92 percent hugged to the right. However, when people hugged their friends or partners at the airport, only about 81 percent of people hugged to the right. Thus, emotions seem to affect hugging side preferences. The left hemisphere of the brain controls the right half of the body and vice versa. Therefore, it is likely that this leftward shift in hugging is due to greater involvement of the right hemisphere of the brain for emotional processes during hugging in these situations.
3. People are either left-kissers or right-kissers
When kissing someone, do you turn your head to the left side or the right side?
Research shows that people have a preferred side to turn their head to when kissing and rarely turn to the other side. In a 2003 study, the author observed kissing couples in public places such as international airports, large railway stations, beaches, and parks in the United States, Germany, and Turkey (Güntürkün, 2003). The result? Most of us are right-sided kissers. Overall, 64.5 percent of couples turned their heads to the right and 35.5 percent turned their heads to the left.
4. We have a preferred side for chewing
Do you have a favorite side to chew your food on while eating?
A 2016 study from Spain and Mexico in 146 young adults found that 56 percent of people consistently chew on one side, with 77 percent of them preferring the right side of their mouth and only 23 percent on the left side (Rovira-Lastra et al., 2016). The remaining 44 percent of people chewed alternating on the left and the right side.
5. We have a favorite cheek to turn when posing for selfies
When posing for pictures, do you have a side of your face that you consider your “good side”?
Interestingly, most of us have a clear preference to put one cheek forward when posing for a picture that is supposed to be posted on social media. A study in which 2000 selfies on Instagram were analyzed regarding the pose of the photographed person (Lindell, 2017) revealed that 41 percent of people show a preference for the left cheek, while 31.5 percent showed a preference for the right cheek. The rest did not show a clear preference for the left or the right cheek. Altogether, 72.5 percent of people had a clear preference for one cheek over the other.
6. Most people cradle a baby on their left side
If you cradle a baby, which arm do you use?
Despite the fact that most people are right-handers, research shows that we show a leftward bias for cradling a baby. A recent large-scale meta-analysis (Packheiser et al., 2020) shows that about 66 percent of people cradling a baby on their left side, while only about 34 percent cradle a baby on their right side.
7. We also have a favorite eye
We do not only a favorite hand and foot, but side preferences can also be observed for sensory organs like the eyes. In a study from 2009, my research team and I determined peoples’ dominant eyes, by asking them which eye they would use to look through a keyhole, down a telescope, and down a monocular microscope (Ocklenburg and Güntürkün, 2009).
About 75 percent of people showed a preference for the right eye, while about 25 percent preferred the left eye for these activities.
Sebastian Ocklenburg, Ph.D. is a lecturer in biopsychology at Ruhr University’s Institute of Cognitive Neuroscience in Bochum, Germany. His research focuses on hemispheric asymmetries in the language and motor systems.