ABSTRACT
Social groups are maintained by communication between individuals, which is brought about by a series of largely innately determined gestures and responses. The way in which the term 'social organization' is used here is a deliberate attempt to place it as an empirical subject, capable of being expressed in terms of quantitative observations. The social organization of a natural group is based on long-term relationships. The Japanese workers have found that mothers in their M. fuscata groups retain a special relation with their daughters long after their daughters mature. Eccentric population composition, and environmental stresses like lack of cover and feeding competition are fairly obvious factors in the extreme conditions of captivity that lead to unusual or unstable social organization. Only for one species, man, is the range of variability in social organization fairly well known, but it is suggested that variability of the same order might reasonably be expected in other primates.
