Abstract: | A cross-sectional analysis was made of developmental changes in mother-offspring grooming in Japanese macaques, Macaca,. fuscata. When offspring were immature, time spent grooming by their mothers decreased with offspring age. Soliciting by offspring increased steadily with age, in contrast to their successful soliciting, which decreased gradually until early adolescence. This is in accord with the hypothesis that grooming is one form of post-weaning maternal investment, which may entail behavioral conflict between mothers and immature offspring. On the other hand, mothers spent much more time for grooming of their adult female offspring than for their adolescent male and female offspring. It is argued that grooming by mothers may shift from a form of maternal investment in their offspring to a benefit to be exchanged reciprocally with them. © 1995 Wiley-Liss, Inc. |