Dr. Jane Goodall touched by Jou Jou
Photo: © Michael Nichols from Brutal Kinship (Aperture)
Chimpanzees and humans share a common ancestry that is evident in our genes, intellect, emotions, and behaviors. We are different branches of the same evolutionary tree.
Common Origins
Humans and chimpanzees evolved in Africa from a common ancestor millions of years ago.1 Years of study have traced and documented our shared origins. Our understanding of chimpanzees has enhanced our knowledge of not only them but also ourselves.
Chimpanzees are the species most closely related to human beings than to gorillas. Fossil and genetic evidence show that human and chimpanzee DNA is approximately 96-98% identical. As a result, chimpanzees and humans share physiological, emotional, and behavioral traits.
Anthropologists estimate that modern human and chimpanzee species diverged from a common prehistoric ancestor between 5 and 10 million years ago (a theory Charles Darwin first proposed in 1871).2 Some scientists believe that chimpanzees—both common and pygmy (bonobos)—should be classified in the same genus (Homo) as human beings instead of being classified alongside orangutans, gibbons, and gorillas. Physiologist Jared Diamond went so far as to call humans "the third chimpanzee." 3
Like human children, young chimpanzees learn life skills via observation and imitation. They pass these lessons on to their children, resulting in a complex socio-cultural system.
Bodies and Health
Biologically, chimpanzees and humans are very much alike. Our bodies are similar in structure, although chimpanzees have significantly more muscle mass, bone density, and consequent strength. An adult male chimpanzee has six to eight times the strength of an adult man.
Both species have relatively long lifespans, although chimpanzees can live 50 years or longer. 4 Cheetah, the oldest known chimpanzee, lived 80 years.
Generations of chimpanzees live together and form long-term relationships, fostering chimpanzee culture.
Like humans, chimpanzees have self-awareness. They can recognize themselves in a mirror. 5 Given this keen sense of self, chimpanzees' individuality is as diverse as it is in humans. Some chimpanzees show enormous kindness or intelligence, and others could be described as more selfish. Some are gentle and nurturing, while others are bullies. Their rich personalities are strikingly similar to humans and explain their complex emotional needs and the rich social fabric of their lives.
Along with self-awareness comes their self-interest. Chimpanzees have the challenge of establishing their place within their society. Some are better skilled at accomplishing this than others. But, within chimpanzee society, each member has a place—be it one of status or marginal involvement.
The link between physical and mental health has been observed in both humans and chimpanzees. Adverse mental states such as grief or depression have detrimental effects on physical fitness in both species. Conversely, positive emotions boost general well-being. 6 Conflicts arise in chimpanzee society just as they do in human society. Chimpanzees are as capable of joyful reconciliation as they are of confrontation.
Chimpanzees and humans share long lifespans and high intelligence. They also share the capacity for establishing long-term relationships, accumulating memories, and possessing a sense of time.
Sources
[1] Stanford, C. (1995, May-June). Chimpanzee Hunting Behavior and Human Evolution. American Scientist.
[2] Hecht, J. (2003, May 19). Chimps are human, gene study implies. New Scientist.
[3] Ibid.
[4] Conservation International. (2002, September). The Western Chimpanzee.
[5] Bright, M. (1994). Intelligence in Animals. London: Toucan Books.
[6] Jane Goodall Institute. (n.d.). So like Us.; and Jane Goodall Institute. (n.d.) Similarities Between Chimpanzees and Human Beings.