This story about an Arab American Muslim buying a dog is very heart-warming and is making the rounds. The author notes that other Americans, who normally might view him as a threat, an alien, now seem to approach him as a human being through the cuddly & approachable vector of his pet. Now it is true that until recently most dogs (though not cats) worked for a living, and the bourgeois ideal of canine companions is not exactly analogous to the life of a sheep dog or a war dog.

Nevertheless, I have mooted the idea before that pets may have a secondary functional role as social facilitators. There is the stereotype of people meeting through their dogs, and there are a few neighbors that I know only because my cat tends to not consider distinctions of property when roaming. The neotonous features of cats and especially dogs in comparison to their wild forebears is pretty evident (everyone wants a perpetual puppy). The farm fox experiment shows that the same microevolutionary selection pressures that reshaped the wolf into the dog can apply to other species. Clearly not only were dogs bred for their direct utilitarian specialties (herding, hunting, defending, etc.), some breeds were also selected by universal human "cuteness" biases (that is, a social selection pressure). Not only do cute dogs appeal to individuals who claim ownership over them, because all minds share some common features, they appeal to other humans beings who we might come in contact with. And so you have a perfect organic interface with which to "break the ice" between people who might be separated by cultural barriers.

Related: In jeet's post below one reader suggests that expensive dog clothing is a status symbol. Again, this is an example where pet culture hijacks common cognitive biases.