Chimpanzees raised by humans are surprisingly antisocial. Primates are becoming increasingly popular as pets. As infants they are affectionate and needy; but by age five they are stronger than their owners and become destructive and resentful to discipline. Therefore, many pets end up in zoos and sanctuaries where they are expected to socialize appropriately with the chimpanzee community. Can a chimp cared for by humans as a baby become a well-adjusted, social adult?
Chimpanzees are among the closest relative of humans. About 98.7 percent of their DNA is exactly the same. The ancestors of the two species diverged approximately four million years ago; but it seems that living with humans is very damaging to chimpanzees. Raising chimps in captivity causes lingering behavioral problems possibly stemming from disconnection from their natural social group.
The study looked only at chimpanzees now living in zoos and sanctuaries, not in the wild. It is unique in that it focused on the amount of time the individuals spent living closely with humans in the first years of life. The study does not address simply taking the animals out of their natural habitat, but examines chimpanzees who were kept as pets or performers. These chimps bonded with humans but lacked connection with peers. Chimpanzees raised by humans behave differently than their fellow primates in adulthood.
The new research on chimpanzees was conducted by the Lester E. Fisher Center for Study and Conservation of Apes at the Lincoln Park Zoo in Illinois. Researchers collected 1385 hours of data on 60 individuals to write the study titled, The Impact of Atypical Early Histories on Pet and Performer Chimpanzees. They observed 36 chimps who were former pets and performers and 24 chimps raised in a chimpanzee family setting. They measured the Chimpanzee-Human Interaction (CHI) to which the subjects were exposed during their early lives. Chimpanzees are vulnerable to impoverished social histories and exhibit abnormal behavior and even signs of mental illness later in life. Does being raised by humans impoverish their social history?
The study found that chimpanzees raised primarily by people showed fewer social competencies. They were less socially adjusted than chimps raised with their families, even in a zoo or sanctuary setting. One indication of antisocial behavior was that the chimps spent less time participating in social grooming. Picking bugs, nits and fleas out of each other’s hair is as much a means of communication as it is a time to touch and show care for one another. Researchers discovered that once reunited with their appropriate social group, the antisocial behavior does not rectify itself but persists for many years. “One of the startling aspects of these findings is that these behavioral effects are so long-lasting, “ says Steve Ross, one the researchers. He says that once chimps are raised by humans, their antisocial behavior makes it “challenging and stressful” to re-integrate them into the wild.
The findings of the study should discourage people from owning chimpanzees as pets. Though chimpanzees are adorable and can exhibit intelligence and behaviors similar to human toddlers, they are wild animals. Chimpanzees deserve the respect that allows them to live as members of their own species and not serve as companions for humans. Living with humans causes chimps to become antisocial because humans cannot provide the same level of care and stimulation as can a chimpanzee mother. The study also helps humans who work with chimpanzees understand the impact of their interaction on the social health of the animal. Human care cannot compensate for lack of a chimpanzee family. It casts doubt on the theory that human-raised primates can be returned to the wild.
If living with humans causes social maladjustment in chimps, what does the increasingly solitary lives lived by humans do to children? Are humans spending enough time properly socializing their children? Are chimpanzees doing something to raise their offspring to behave in a socially conscious way that humans are not doing?
Chimpanzees who are not raised in a typical family with their mothers and appropriate social interaction can develop mental and emotional issues. By studying chimps, people can learn about effects of social impoverishment that may relate to humans. Additionally, the new study provides more evidence that people should not keep chimpanzees as pets. Chimpanzees raised by humans are surprisingly antisocial and have a hard time fitting in with other chimps later in life.
By: Rebecca Savastio