Читать книгу Introducing Anthropology - Laura Pountney - Страница 35
Social relations
ОглавлениеHumans and some nonhuman primates share certain similarities in their behaviour towards each other. However, social behaviour varies from species to species. Two examples of nonhuman primate behaviour are explored here: of bonobos and of chimpanzees, our two closest evolutionary relatives.
| Bonobos (© LaggedOnUser / Flickr) Bonobos, found living in the forests of the Democratic Republic of the Congo, have been noted for their sociability. Groups of bonobos range from about 50 to 100 individuals; however, these groups do break up during the day to form foraging parties. Every night bonobos make a sleeping nest from branches and leaves, usually nesting with the smaller group they have travelled with. Bonobo societies are female-centred in structure. Interestingly, like humans, bonobos have sex for purposes other than reproduction. They often manage and resolve social conflicts through sex, making aggression less common than with chimpanzees. In fact, sex is a very important part of the social relations of bonobos. They engage in both homosexual and heterosexual relations, although incest is generally avoided. Sexual interactions occur more often among bonobos than among other primates. Despite the frequency of sex, their rate of reproduction in the wild is about the same as that of the chimpanzee. Bonobo communities have ranges that overlap with other groups. Males are protective of other members of their group and carry out any hunting. Males typically remain among their family group while females range further afield. While males show aggression towards each other, conflict rarely escalates into acts of physical violence. In spite of physical superiority, evidence suggests that males are not aggressive towards females. Bonobos are social animals, and food sharing occurs between males and females, unlike the situation with chimpanzees. Also the female–female relationship is much stronger in this species than it is for chimpanzees. Although they seem very lively, bonobos, like humans, control their emotions when expressing themselves in times of happiness, sorrow, excitement or anger. They are very animated and perform similar gestures to humans when communicating without using language. For example, they will beg by stretching out an open hand or foot and will make a whimpering sound if they fail at something. Females become sexually mature after about twelve years of age and may give birth soon thereafter. They have babies at five- to six-year intervals, so population growth can never be rapid. As with humans, there is a relatively long period of socialization for the young. Females nurse and carry their babies for five years, and the offspring reach adolescence by the age of seven. Females have between five and six offspring in a lifetime. | Chimpanzees (Matthew Hoelscher / Wikimedia Commons) Common chimpanzees, living in tropical forests of Africa, live in small communities. These typically range from 20 to more than 150 members; however, chimpanzees spend most of their time travelling in small, temporary groups consisting of a few individuals that are made up of any combination of ages and sexes. Both males and females will sometimes travel alone. Chimpanzees, like humans, have complex social relationships and spend a large amount of time grooming each other. Grooming is an important way in which alliances are built. Chimpanzee society shows considerable male dominance. Interestingly, male aggression has an important function in establishing a social hierarchy. However, aggression is often only displayed rather than followed through with violence. Males maintain and improve their social position by forming coalitions. These coalitions increase their influence, giving them power that they would not be able to gain alone. Social hierarchies among adult females tend to be weaker. Nevertheless, the status of an adult female may be important for her offspring. Chimpanzees have been described as highly territorial and have been known to kill other chimps for territorial dominance, although there is some suggestion that highly aggressive behaviour by chimpanzees happens only when artificial feeding occurs. A female may mate with several males, though a dominant male may stop other males gaining access to the female with whom they are consorting. Infanticide (the killing of babies) has been recorded among chimpanzees. This is often carried out by male coalitions that invade an existing group, expel their dominant males and kill their offspring: the new males do so in order to mate with the same females and have their own offspring. Care for the young is provided mostly by their mothers. As with humans, babies are dependent on care from an adult for a substantial period. Mothers provide their young with food, warmth and protection and teach them certain skills. In addition, a chimp’s future rank may be dependent on its mother’s status. For their first year, chimpanzees cling to their mothers. By the time they are six, adolescents continue to spend time with their mothers. Like humans, chimpanzees use their highly expressive faces, postures and sounds to communicate with each other. There are many different sounds which signify specific meanings, such as danger, excitement and anger. |
