In the non-mating season, subgroups form within the main group based on, for instance, age, sex or family roles. These subgroups are abandoned during the mating season. Group size is affected by habitat. Squirrel monkeys display female dominance, with the females forming the central core of the group, or troop. Some temporary relationships may form between a mother with no infant and another female's infant.
Males also display a clear dominance hierarchy.
There are no territorial disputes, groups tend to mutually avoid one another. Groups may sometimes be found together, but not for long and perhaps only to search for food. Habitat Squirrel monkeys prefer primary and secondary forest, gallery forest and forest edge. They prefer the intermediate forest levels, but they can sometimes be found on the ground or in upper canopy levels. They occupy many different types of forests.