Chimpanzees empathize with group mates and humans, but not with baboons or unfamiliar chimpanzees

Abstract

Human empathy can extend to strangers and even other species, but it is unknown whether non-humans are similarly broad in their empathic responses. We explored the breadth and flexibility of empathy in chimpanzees, a close relative of humans. We used contagious yawning to measure involuntary empathy and showed chimpanzees videos of familiar humans, unfamiliar humans and gelada baboons (an unfamiliar species). We tested whether each class of stimuli elicited contagion by comparing the effect of yawn and control videos. After including previous data on the response to ingroup and outgroup chimpanzees, we found that familiar and unfamiliar humans elicited contagion equal to that of ingroup chimpanzees. Gelada baboons did not elicit contagion, and the response to them was equal to that of outgroup chimpanzees. However, the chimpanzees watched the outgroup chimpanzee videos more than any other. The combination of high interest and low contagion may stem from hostility towards unfamiliar chimpanzees, which may interfere with an empathic response. Overall, chimpanzees showed flexibility in that they formed an empathic connection with a different species, including unknown members of that species. These results imply that human empathic flexibility is shared with related species.

Experimental evidence of contagious yawning in budgerigars (Melopsittacus undulatus)

“…In particular, contagious yawning is thought to represent a basic form of empathy rooted in a perception-action mechanism known as state matching or emotional contagion (Preston and de Waal 2002). Consistent with this view, previous research has documented a strong association between contagious yawning and empathy (for a discussion, see Campbell and de Waal 2014). For example, in humans, contagious yawning is more common among participants who score high on empathy measures (Platek et al 2003; but see Bartholomew and Cirulli 2014), and thinking about yawning has been shown to activate brain areas implicated in empathic processing (e.g., Platek et al 2005;Nahab et al 2009).…”

“…In particular, captive chimpanzees shown video stimuli of other chimpanzees yawning demonstrate contagion to ingroup members but not to unfamiliar conspecifics. Subsequent studies, however, have failed to demonstrate a familiarity bias for chimpanzees viewing human yawns (Campbell and de Waal 2014;, and at least one study provided evidence that relationship quality among chimpanzees did not predict yawn contagion (Massen et al 2012). There has also been mixed support for domesticated dogs to yawn more in response to yawns from familiar humans O'Hara and Reeve 2011).…”

“…To date, experimental evidence of contagious yawning is restricted to humans (Homo sapiens; e.g., Provine 1986;Platek et al 2003), chimpanzees (Pan troglodytes) in response to conspecifics (Amici et al 2014;Anderson et al 2004;Campbell et al 2009;Campbell and de Waal 2011;Massen et al 2012) and human yawns (Campbell and de Waal 2014;; but see Amici et al 2014), domesticated dogs (Canis familiaris) in response to human yawns (Joly-Mascheroni et al 2008;Romero et al 2013;Silva et al 2012; but see Harr et al 2009;O'Hara and Reeve 2011;Buttner and Strasser 2014), and, most recently, a subline of high-frequency yawning Sprague-Dawley rats (Rattus norvegicus; Moyaho et al 2014). Video-induced yawning has also been reported in stumptail macaques (Macaca arctoides; Paukner and Anderson 2006), but this response also cooccurred with heightened self-directed behaviors and thus appears to be due to social tension or stress rather than contagion.…”

Horses discriminate between facial expressions of conspecifics

“…)27. In line with this, horses exhibit some of the social skills suggested to be necessary for navigating a fluid and dynamic social environment2829: horses can perform individual recognition of social partners303132, they have good long-term memories33, they engage in post-conflict consolation34, and they intervene in third-party social interactions35.…”

Infants' Speech Segmentation: The Impact of Mother-Infant Facial Synchrony

“…It is worthy of note that the mimicking facial expressions described here is not an ability exclusive to humans, but an ability that is common to other mammals (Campbell & de Waal, 2014). Therefore, facial expression reciprocity is likely biologically programmed in mammals, and the amount of mimicking, in regards to facial expressions, often indicates the degree of familiarity in human interactions.…”