In 2011, Chinese media reported that a bear held captive on a bile farm killed her son and then herself to escape from the torture of their situation. In 2012, Psychology Today blogger Marc Bekoff wrote a post about a burro who, after the death of her infant, walked into a lake and drowned herself. Last year, a friend told me a story about her dog Lucy, who stopped eating after the death of her longtime companion, Steele. Lucy died three weeks after Steele.

Although many people are quick to brush off the question “Can animals commit suicide?” as silly, and fantastically anthropomorphic, we ought to stop and give the question some serious thought. Typically, our dismissal is rooted in the belief that animals are simply incapable of the kind of self-reflective, purposeful behavior that makes human suicide what it is. Taking one’s own life goes strongly against the evolutionary impulses of self-survival and requires a conscious decision to override those impulses through an act of . It also requires an awareness of death. And animals, we believe, just don’t have these capacities.

This assumption goes wrong in at least two different ways: it overstates the “free will” and “conscious self-reflective” nature of human suicide; and it ignores a wealth of empirical evidence about the cognitive capacities of nonhuman animals, including a growing research database on death-related behaviors in a wide range of species.

In "Can nonhuman animals commit suicide?" published recently in the journal Animal Sentience, David Peña-Guzmán, a professor from San Francisco State University, lays out a very strong case that nonhuman animals can and do engage in self-initiated behaviors that bring about self-harm or death and that there is no good scientific or philosophical reason to think these are different in kind from what occurs among the human species. (The article is worth reading in its entirety.) To begin, Peña-Guzmán takes up some of the reasons why animals might not be capable of behavior. For example, he explores whether the current empirical database supports the claim that only humans have the kind of reflective, self-conscious subjectivity that is thought to be necessary for suicide. It does not. Instead, research suggests that human and animal minds are far more alike than they are different, and that all animals (human and nonhuman) exist along a cognitive continuum. Animals, like humans, possess “at least three different types of subjectivity . . . [which] crisscross the animal kingdom in elaborate and nonlinear ways.”

Peña-Guzmán also argues that “suicide” is better understood not as a single behavior, but a broad range of self-destructive behaviors. These self-destructive acts run along a continuum, from behaviors that are likely strongly explained by evolutionary accounts of kin selection (wasps who sting themselves to death after copulation) and ecological theories (dispersal behaviors that explain the self-destruction of lemmings), to behaviors that seem to parallel more strongly what we typically think of as a human suicide. On this end of the continuum, Pena-Guzman offers the example of captive animals who engage in -related self-harming behaviors. One, a dolphin named Kathy, grew increasingly after living her whole life in captivity, and may have killed herself. (Kathy’s story is featured in the 2009 documentary The Cove.)

The idea that animals can and do engage in self-harming and self-destructive behaviors, even to the point of causing their own death, is challenging on many fronts. It upsets our folk belief that humans alone possess subjective awareness and are qualitatively different from animals. It suggests that animals have a level of “decisional and volitional capacities” that go well beyond what we typically ascribe to them. The recognition of this ability would have far reaching ethical implications. For example, if animals can dissent from various kinds of interactions with humans, shouldn’t we find ways to respect their choices by allowing them to opt out of research protocols they find painful or frightening? (Gregory Berns has done just this with his research on the neurophysiology of dog brains. His research is noninvasive, involving only the use of an fMRI machine, and his research subjects are invited to participate and can decline participation. See his book, How Dogs Love Us.)

If animals can engage in suicidal behaviors, this seems to presuppose some broader awareness of death. And if animals have a concept of death, this could have important welfare implications for captive animals. For instance, the research done by James Anderson and his colleagues on the reactions of a group of chimpanzees to the death of one of their group members found that the chimpanzees displayed a suite of behaviors very much like what we see in human groups: they checked for signs of life, groomed the body, stood vigil over the body, and mourned for their companion. One of the of animal welfare is to provide captive animals as many opportunities as possible to engage in normal species-specific behavior, and death-related behaviors should certainly be included.

One final question raised by Peña-Guzmán is whether captivity itself is a risk factor for animal suicide. Some of the self-destructive behaviors recorded in the ethological literature arise from stresses related to captivity: self-biting, , self-endangerment. “If,” he writes, “certain animals are shown by future research to be statistically more likely to self-destruct in certain environments, we may have a moral duty to change those environments or relocate those animals.” This could be a game changer.