Unable to cope, some chimpanzees resort to self-mutilation, including biting themselves, attacking a limb that they dissociate as being their own, pulling their hair out, rubbing their skin raw, or hurting themselves in other ways—behaviors that in humans would be described as having “gone crazy.”
Others develop compulsive behaviors: rocking uncontrollably back and forth; eye or ear poking; head rolling; pacing; or, smearing, playing with, or eating their feces. Faced with similar isolation, human prisoners of war have described their own need to pace endlessly. They explain that it helped remind them that they were alive.
Out of frustration or an effort to get attention, some chimpanzees spit water or throw feces. According to former caregivers, some lab workers don’t have the empathy to understand or tolerate this behavior and retaliate with punishment.
Current studies by psychologists and chimpanzee experts are showing that chimpanzees not only suffer physically and psychologically in labs, but many exhibit lifelong symptoms of trauma, even after release into sanctuary. Post-traumatic stress disorder (PTSD), as well as other human psychological maladies, afflicts chimpanzees from laboratories in the same way as it afflicts human trauma survivors, according to a paper published spring 2008 in vol. 9 (1) in the Journal of Trauma and Dissociations: "Building an Inner Sanctuary: Complex PTSD in Chimpanzees." Tragically, psychological suffering crosses species lines.
"Building an Inner Sanctuary…" analyzes case material of two chimpanzees rescued from research, Jeannie and Rachel. Diagnosed with complex PTSD, Jeannie and Rachel demonstrate that chimpanzees, like humans, suffer when confined, stripped of agency, repeatedly physically injured, and subjected to constant fear and stress. Their symptoms—hypervigilance, dissociating, violent self-attacks, insomnia, ritualistic behaviors, inability to tolerate touch and limited social sills—are representative of human trauma survivors as well as other chimpanzees from research.
“The paper challenges a system that likens chimpanzees to humans when attempting to justify their use to study human biological disease, but refuses to acknowledge the full extent of their emotional, behavioral, and cognitive similarities since that acknowledgement argues vehemently against their use,” says Dr. Theodora Capaldo, NEAVS president, psychologist and co-author or the papers.
Although the NIH accepted most of the IOM’s recommendations to promote the psychological well-being of chimpanzees, the Animal Welfare Act (AWA) requirements for “psychological enrichment” for nonhuman primates remain vague and, according to former caregivers, many facilities meet only the bare minimum or get around them entirely.