Social play behaviour in young rhesus monkeys Macaca mulatta at three different ages: from the 3rd to the 6th month of life.

Social play behaviours were investigated in 17 young rhesus monkeys Macaca mulatta, belonging to a large captive group, at three ages: 3/4, 4/5 and 5/6 months. Play initiatives were recorded (TO/BY) and the infants' partners were divided into five age groups (mothers, adults, similar-age infants, 1-yr-old infants and 2-yr-old infants). The findings suggest that mothers do not participate very much in the play initiatives of their offspring, but they do control it and, at an early age (3/4-4/5 months), they differentiate between sons and daughters. After this age, the infants seem to be more free in their choice of partners, even though infants appear to be more comfortable with their contemporaries rather than with infants of a different age.