Female-left and male-right positioning by young Japanese couples

I discovered a phenomenon related to nonverbal sex differences in young Japanese couples in which the female tends to assume the left side position and the male tends to assume the right position (FM tendency) when the couple are walking on sidewalks and in parks. As the first step of the present study, some aspects of this phenomenon were examined through field observation. In total, 2,827 couples (teens and 20s: 1,799; 30s and 40s: 732; older than 50: 296) were examined. The following facts were clarified: (1) Couples in their teens and 20s couples showed a clear FM tendency, and couples older than 30 did not. (2) The FM tendency in couples in their teens and 20s was seen in all places where observations were done (street, sightseeing park, shopping center). (3) The FM tendency was seen when neither the female nor the male was carrying anything. Each person tended to take a position to avoid having any parcel, handbag, or other item between the partners. (4) The FM tendency was seen when neither partner touched the other, and when both partners reciprocally touched. When only the female touched her partner, the FM tendency was especially conspicuous. When only the male did, the FM tendency was not seen. As an essential causation of the FM tendency, the intention by females to touch their partners by the dominant right hands was suggested.