Bonobos and ‘Xenophilia’
Humans have been studying primates for a very long time, sometimes seeking answers to questions about them, and sometimes seeking answers to questions about ourselves. Bonobos are one of the species we’ve studied extensively, both in the wild and in captivity. Bonobo societies share many characteristics of human societies, and studies of bonobos have yielded many fruitful comparisons to humans.
In this study, researchers wanted to look at a specific aspect of bonobo culture — their openness to “unfamiliar conspecifics,” (other bonobos who aren’t part of their immediate familial trust groups) — and understand what it says about their levels of trust and “xenophilia,” the affinity for unknown objects or people. Indeed, past studies have shown that bonobos will go to some lengths to help other bonobos who are unknown to them, “even when they received no social reward,” and they will allow outside members into their group even when it means they’re outnumbered, something chimpanzees actively avoid.
To study this phenomenon, the researchers first looked at whether bonobos would provide food to an unfamiliar conspecific who was “unable to use overt signals to indicate their desire for help.” Then, in an interesting twist, the researchers tested whether bonobos have an “involuntary contagious yawning response to complete strangers,” which they note has been used as “as an implicit measure of social preference in various primates and non-primate species since it is under involuntary control.” What they found was that bonobos did indeed proactively help out the unfamiliar conspecific, and also showed involuntary contagious yawning when tested with complete strangers. They note that the “proactive prosociality” is in keeping with previous studies, but the involuntary yawning shows that their xenophilia may not be “completely under voluntary control and is present even when there is zero familiarity.”
The researchers say the results imply that, like humans, bonobos seem to want to make a “good first impression” when interacting with new social partners. For both humans and bonobos, “many strong bonds likely start from positive encounters between unfamiliar adults catalyzed by xenophilia.” However, the researchers also note that, humans often have “strong xenophobic reactions” to “different culturally mediated outgroups.” They conclude that “bonobo networking” has very much to teach us about “the origins of the human network we all rely upon.”
Studying other species can sometimes tell us a great deal about ourselves, but animal advocates know there are many ethical issues with studying species in labs or other situations of captivity. Such studies have the power to show humans that there are important similarities among species, but such similarities are a moot point if we continue to treat them unethically. This study, for its part, was conducted at a Bonobo sanctuary in the Congo, where orphans from the bushmeat trade were living in social groups, with access to a heavily forested enclosure. Additionally, the “research subjects” were “never food or water-deprived,” and “they could leave the testing rooms any time by sitting next to the exits.” Studies conducted in this way show that, not only can we learn something from primates that might tell us more about ourselves, but there are ways to do that research that are more ethical, and don’t require a brutal form of captivity usually characterized by lab studies.https://www.nature.com/articles/s41598-017-15320-w
February 8, 2018 - by Karol Orzechowski
Tan, J., Ariely, D., & Hare, B. (2017). Bonobos Respond Prosocially Toward Members Of Other Groups. Scientific Reports, 7.