Behavioural Development in Chimpanzee (Pan troglodytes) and Human Newborns Across the First Month of Life

Comparisons among the behaviours of chimpanzee (Pan troglodytes) and human newborns on a standardised human neonatal assessment scale are reported for the infants at both 3 days and 1 month of age. Human infants scored significantly higher on the orientation cluster at both ages, and relative to the chimpanzee infants were lower in motoric maturity. With respect to the human standards employed, the two chimpanzee infants who were human-reared scored as optimally as did the human infants at 1 month, suggesting a differential impact of the care-giving environment on developing chimpanzee social behaviours.