James Serpell on Interspecific Friendship

Human friendships share many features in common with certain social relationships in other species, particularly among non-human primates. The requirement, however, that friends should value the relationship itself above and beyond the gratification of personal ambitions, seems to be unique, and is uncharacteristic of analogous relationships among animals living under natural conditions. Human friendships, and the particular rules of conduct associated with them, probably evolved in the face of increasing social pressures which necessitated the formation of durable, reciprocal alliances with individuals other than kin or sexual partners. Since such alliances are expected to last a long time, perhaps for the lifetime of the individual, the process of friendship-formation places the emphasis on mutual liking, trust and compatibility, rather than on the prospect of immediate or even deferred material gains.

Despite the apparent absence of true friendships among animals, humans are able to derive many of the social and emotional benefits of friendship from relationships with animals, especially dogs, cats and other household pets. Perhaps because they involve other species, and therefore appear superficially counterfeit, such relationships between humans and animals have been largely ignored by ethologists and social psychologists. This is, perhaps, regrettable, since their particular differences and similarities may reveal a great deal about both the meaning and the limits of friendship.

(James Serpell, "Humans, Animals, and the Limits of Friendship," chap. 7 in The Dialectics of Friendship, ed. Roy Porter and Sylvana Tomaselli [London and New York: Routledge, 1989], 111-29, at 127-8)