Laterality of face orientation in traditional Japanese portraits.

The left face (cheek) bias, predominantly associated with female sitters, is prevalent in Western portraits and photographs. This bias toward the left cheek can be explained by the idea that the left side of the face is more expressive than the right, based on its association with emotional processing in the right hemisphere. We investigated whether left-face bias is also observed in Japanese portrait paintings, which have different cultural backgrounds and styles. We studied 614 portraits of 112 women and 502 men from the Heian to Meiji period (roughly corresponding to the 9th to 19th centuries). Of them, only five were frontal portraits (all were of male monks). Of the remaining 609 (depicting 112 women and 497 men), 349 were left-faced (57.3%), indicating a significant left-face bias. Furthermore, 61.6% of female portraits compared to 56.3% of male portraits were left faced. Analysis of male portraits by vocation showed a significant left-face bias for "samurai" and "painters and literati," while a right-face bias for "monks." These results are discussed from the perspectives of neuropsychology and cultural studies.