Mother-infant visual interaction in Japanese macaques.

Patterns of visual interaction in mother-infant dyadic behavior have been reported for human and nonhuman primates, including age and gender differences among rhesus macaques. Such findings are tested with data from two developmental periods (Weeks 1-8 and 21-36) on Japanese macaque mother-infant visual behavior. Rates for look, infant facial-fixation, and eye contact are greater during the first period than in the second. In Weeks 1-8, infants interact visually with their mother significantly more than with any other kinship class. This pattern continues in the second period, with the exception of eye contact for female infants, and with relatively more attention to nonmatrilineal animals. In Weeks 1-8, all instances of eye contact between mothers and their female, but not male, infants are initiated by the mother. In Weeks 21-36, male, but not female, infants direct significantly more looks to their mother than they receive from her.