Primate sociality is an area of primatology that aims to study the interactions between three main elements of a primate social network: the social organisation, the social structure and the mating system. The intersection of these three prinate describe the socially complex behaviours and relationships occurring among adult males and females of a particular species.
Primate social organisation exists along a spectrum, with networks ranging from the solitary neighbourhood systems to the multi-individual units to the complex multilevel societies that primate mating systems composed of hierarchically-organised social sysgems.
The evolution of diverse primate social systems is considered to be a naturally selected anti-predation response. Similar to genetic traits, behavioural characteristics can similarly result from natural selection processes. In opposition to many animal-decision making strategies which encourage individual fitness, group living or sociality prioritises an inclusive group fitness. For example, the main benefits of group living are hypothesised to be:.
Interestingly, there are competing hypotheses for the role feeding takes in influencing primate sociality. It is interpreted as having both as a positive resource detection and negative resource competition effect depending on the analysis.
In order for sociality to have been selected for via natural selection, the collective benefits of group living must outweigh the collective costs. Social organisation refers to the size number of individualscomposition variation between primate mating systems sexesand cohesion relating to proximity and bond strengths among individuals of the society in consideration. Interestingly, primate social organisation is not necessarily species-specific. For instance, an example of within species intra-species variation would be tamarins and marmosets.
These two primates are part of the callitrichidae family and have been observed to demonstrate pair-bonding systems in some populations while others have one-male unit OMU systems. Solitary primate systemssometimes referred to as neighbourhood systems, occur when an adult male's territory overlaps with one or more adult female's territory and individuals conduct activities most often foraging or offspring care independently from one another.
Examples of solitary primates: orangutansgalagos primate mating systems, lorisessome species of lemurssome tarsiers.
Pair-bonded systemsor pair-living primates, are small social units consisting of one adult male and one adult female, and their immature offspring. There are factors of time and space that define this type social system.
Firstly, pair-bonds must demonstrate a long-term affiliative partnership for at least one prinate or one seasonal cycle. Secondly, there must also be a higher frequency of association spatial proximity between the bonded-pair individuals than there is with other individuals. Paternal care of offspring is a relatively uncommon trait in primate social systems;  however, the monogamous mating system often observed though it should not be assumed in pair-bonding generates an equal variance for offspring success primate mating systems both pair members.]