Why do people love their pets?

The evidence that people form strong attachments with their pets is briefly reviewed before identifying the characteristics of such relationships, which include pets being a source of security as well as the objects of caregiving. In evolutionary terms, pet ownership poses a problem, since attachment and devoting resources to another species are, in theory, fitness-reducing. Three attempts to account for pet keeping are discussed, as are the problems with these views. Pet keeping is placed into the context of other forms of interspecific associations. From this, an alternative Darwinian explanation is proposed: pets are viewed as manipulating human responses that had evolved to facilitate human relationships, primarily (but not exclusively) those between parent and child. The precise mechanisms that enable pets to elicit caregiving from humans are elaborated. They involve features that provide the initial attraction, such as neotenous characteristics, and those that enable the human owner to derive continuing satisfaction from interacting with the pet, such as the attribution of mental processes to human-like organisms. These mechanisms can, in some circumstances, cause pet owners to derive more satisfaction from their pet relationship than those with humans, because they supply a type of unconditional relationship that is usually absent from those with other human beings. (C) 1997 Elsevier Science Inc.