Consistency in maternal behavior within families of free-ranging rhesus monkeys: An extension of the concept of maternal style.

This paper assesses the extent to which free-ranging rhesus monkeys (Macaca mulatta) on Cayo Santiago show consistent mother-infant interaction with individual infants over time and consistent maternal styles from one infant to another. Inter-pair differences in several measures of mother-infant interaction related to proximity and contact were correlated positively and highly significantly between 6-week age periods. Analysis of variance methods were used to show that, after the first 6 weeks, these measures of interaction were also more similar among pairs with the same mother (i.e., families) than among pairs with different mothers. Differences between families were also consistent between age periods, and appeared to be due primarily to differences between mothers rather than to differences between sets of infant siblings. The results suggest that the concept of maternal style can be used to describe variation between both individual Cayo Santiago mother-infant pairs and between individual Cayo Santiago mothers.