It is widely known that chimpanzees are humans’ closest genetic relatives. That similarity is not simply physical, but also social and psychological. These animals have long astounded researchers with their cognitive abilities (e.g., short-term memory that is far superior to that of humans), and they forge strong social bonds with their family members and friends and can be empathetic and altruistic.
There is mounting evidence about the ill effects of captivity on chimpanzees’ health and well-being. In a recent study, PCRM researchers Hope Ferdowsian, M.D., M.P.H., and Debra Durham, Ph.D., found that previously-traumatized chimpanzees exhibit signs of mood and anxiety disorders such as major depression and posttraumatic stress disorder. Chimpanzees observed in the study, who had previously been used in laboratory experiments or were victims of abandonment and illegal trade, displayed behavioral outbursts, apathy, hypersomnia, and other abnormalities, all of which were virtually nonexistent in their wild counterparts.
Due to the ethical implications raised by chimpanzees’ social and psychological capabilities, most countries have abandoned the use of chimpanzees in invasive experiments. The United States, where about 1,000 chimpanzees remain in laboratories, has not yet followed their lead.
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