Empathy

There is currently no evidence to support the presence of human-like empathic abilities in non-human apes, but proto-empathic abilities have been observed in apes and possibly monkeys. Human empathy is defined as the ability to detect, predict, or attribute an emotional state of a conspecific, understand the experience of that emotional state, and have an emotional response to the emotional state of the conspecific (de Waal 2008). Empathy is central to normative human sociality, and the inability to empathize is symptomatic of certain neurodevelopmental pathologies and mental disorders. Rudimentary empathic abilities are observed in children by two years of age, most commonly in the form of helping behaviors, and significant gains in empathic ability are correlated with language development and Theory of Mind (Zahn-Waxler et al. 1992; Wellman et al. 2001).
In the context of animal behavior, empathy is relatively synonymous with sympathetic concern, or the condition in which one party is affected by another’s emotional or arousal state. At this lowest cognitive power of empathy, it is suggested that humans are not unique, and that there is a continuity of empathy between humans and other primates. For instance, if an infant rhesus monkey is screaming, other surrounding infants will attempt to stop the screaming by embracing or sitting on the distressed infant, likely to reduce their own distress response (deWaal 2008). While anecdotal, apparent gestures of consolation have been observed in chimpanzees, whereby an uninvolved third party seems to comfort the loser of an aggressive encounter by wrapping its arms around the loser’s shoulders (deWaal and van Roosmalen 1979). Some argue that such behavioral displays go beyond sympathetic concern and provide evidence of theory of mind or perspective taking, and thus are empathic displays comparable to human empathy (deWaal 2008).
Another other-centered emotional response that is sometimes referred to as empathy in the context of animal behavior is vicarious emotion. Vicarious emotion, or an affective response to a conspecific’s physical, rather than emotional, state, is thought to be present in most social species (Preston and deWaal 2000). For example, laboratory pigeons that have experienced electric shocks become distressed when observing another pigeon receive a shock (Wantanabe and One 1986), and mice receiving pain stimulus while observing a familiar cage mate also receive pain stimulus have a far greater pain response than isolated mice (Langford et al. 2006). A large body of research supports similar findings in a diverse array of social animals, with the general consensus that vicarious emotion is not limited to humans or primates.
The evolutionary origin of empathy is thought to have emerged from parental care (Decety 2011; Maclean 1985). All animals that require some degree of parental care after birth have mechanisms that convey their emotional state in order to gain parental attention to meet their needs of survival, such as crying (humans) or chirping (birds). It is likely that parents who were better attune to their offspring’s emotional state provided their offspring with better care, and thus had better reproductive fitness than parents unaffected by their offspring’s emotional state. Once the empathetic response in parental care behavior evolved, an accompanying evolutionary increase in neuroplasticity and flexibility, particularly in the prefrontal cortex, probably allowed for some animals to widen empathetic response to include other conspecifics in their social group. This increased awareness of others’ emotions would enable these animals to better navigate an increasingly complex social environment and form closer, cooperative social relationships, increasing survival (Decety 2011). While this cannot be directly tested, behavioral observations from extant social species, such as the continued use of distress calls in adult animals, which resemble the distress calls of young infants, support the hypothesis that the origins of empathy lie in mechanisms of parental care (deWaal 2008).