Facial communication between mother and infant macaque monkeys, part 2

A mother gesturing at her 6-day-old infant. The type of gestures that can be observed (lipsmacking and teeth-chatter) are common among rhesus macaques. What is striking here is the exaggeration of the gesture that is accompanied by head-bobbings in order to further attract infant attention. This seems to be specific to mother-infant relationship. The exaggeration of facial displays and other modifications of the behavior in humans (e.g., the high pitch in the voice) are typical ways of communicating between mother and infant, the so called 'motherese.' Our study demonstrated that these types of gesturing are very common during the first three weeks of the infant macaque life. However, their functions remain unclear. See the paper by Ferrari et al., Current Biology 19(20), published online Oct. 8, 2009: https://www.cell.com/current-biology/...