Researchers interested in the perception of human faces have studied the left cheek bias. There is laterality, or side asymmetry, in how the human face is shown in visual depictions. One theory behind this research is based on differences in right versus left hemisphere processing. The lower portion of the face is innervated by the opposite hemisphere. The right hemisphere controls the left side of the face while the left hemisphere controls the right side. Statistically, when posing for photos or drawings, people should pose with the left cheek forward 50% of the time and with the right cheek forward the remaining 50% of the time. However, many studies report a majority preference for poses with the left cheek forward. This left cheek bias is explained by the notion that the left side of the face is more expressive than the right side based on its connection to the processing of emotion in the right hemisphere. I have discussed the left cheek bias as seen in both photos posted on social media ¹ and in painted portraits ² in two previous blog posts. Recently, I discovered a lecture on the left cheek bias by I.C. (Chris) McManus, one of the world’s leading experts on handedness and other forms of laterality. Chris McManus spoke at the 23rd Oslo Virtual Colloquium in November 2023. The lecture is available on YouTube (McManus lecture).
Last year, 2023, marked the 50th anniversary of the publication of a paper by Chris McManus and Nick Humphrey titled Turning the left cheek. The paper was published in 1973 in the scientific journal, Nature. In his lecture, Chris McManus reflects on the findings of his fifty-year-old study. The authors examined over 1400 facial depictions and found that 60% of them showed the left cheek forward. The left cheek bias was stronger for pictures of women (68%) as compared to men (56%). The effect was larger when both the head and body were shown as compared to the head alone.
As the lecture progresses, Chris McManus discusses a second paper titled Status and the left cheek, also published in 1973 with Nick Humphrey, in the journal, New Scientist. In this paper, the authors presented data collected from portraits painted by the Dutch artist, Rembrandt van Rijn (1606-1669). The authors separated the various portraits into five groups. There were self-portraits of the artist, portraits of male family and non-family members, and portraits of female family and non-family members. Only 16% of the artist’s self-portraits showed the left cheek forward. This minority result was also true for the male portraits, 18% of the portraits of male relatives, and 39% of those of non-relatives. Only the female portraits showed the left cheek bias majority, 56% of the portraits of female relatives, and 79% of those of non-relatives.
The authors do not explain their results using the traditional neurological explanation described at the beginning of this post. Rather they propose the right and left sides have a different meaning or symbolism; the right and left cheeks are not the same. They suggest that when an artist is painting a subject that is like himself, in the case of Rembrandt a self-portrait or a portrait of a male, the right cheek is presented in the forward position. When the subject is not like the artist, the portrait is painted with the left cheek in the forward position. This interpretation explains the large sex difference in portrayals of the left cheek bias in Rembrandt’s portraiture work. Only the majority of portraits of women subjects, who are unlike the artist, show the left cheek bias.
Chris McManus discusses other topics I have not considered here including a description of the left cheek bias in paintings of the Madonna and Christ Child. It is worth listening to the lecture in full especially for those readers interested in art interpretation.
¹ Turning the left cheek. January 11, 2020.
² The left side is the right side. January 23, 2021.