Gibbons can afford to form small groups because their arboreal nature keeps them protected from most predators. They do not require selfish herd or specific lookout behaviors because predation pressure is low. This, along with the food distribution makes gibbons adaptive for the formation of small, nuclear family groups. Since the food is distributed in small patches, only enough food is available in a defensible area for one family.

Both females and food distribution determine territory formation in the gibbon. Because of their aversion to each other, females disperse themselves in order to avoid confrontations. In avoiding each other, they disperse themselves according to the food distribution because their priority is to have plentiful food for themselves and their offspring. The males, then, follow the females and defend the territory they have chosen. The territory is defensible because the food is plentiful in small patches.

Monogamy is a result of the gibbon young’s prolonged dependence and slow maturation rate. In order to produce healthy, successful offspring, parents must spend great amounts of time and energy invested in their offspring. This amount of investment is only possible through a lifelong monogamous bond between the mated pair. The amount of investment required to maintain the territory along with caring for the young requires that both members of the pair always be present in order to fulfill the needs of both the territory and the offspring.