With the arrival of warm spring weather, the purse pup is popping up again. Chihuahuas, pugs, terriers and other scantily furred little dogs won’t convulse to death if taken outdoors anymore, so their Los Angeles owners can once again sport them as accessories.

You don’t see people wearing kittens, parrots or hamsters. Dogs are unique as the primary element to many people’s fashion statements; they’re so beloved to man and lady that we have incorporated them into our wardrobes.

But what makes dogs so lovable? According to recent research, it’s because they remind us of ourselves.

Dogs mirror the qualities that make us human — differentiating themselves from other domesticated animals that have yet to wrestle the title of “man’s best friend” away from the paws of our canine companions.

A recent Associated Press-Petside.com poll found that 74 percent of participants were dog lovers, while only 41 percent were cat lovers.

Our infatuation with dogs is clearly visible around campus.

It’s been more than half a century since the death of George Tirebiter, the shaggy little mutt whom USC students once adopted off of the streets and made into our temporary mascot, yet he stands immortalized in statue form on Trousdale Parkway.

Further, strays who linger around campus are finding friends in the area. Students on 36th Street helped to collaboratively feed a one-eyed mixed-breed pit bull; in another outpouring of compassion, a female golden retriever lab was traded from house to house on Menlo Avenue, until students finally found her a home.

Matteo Marjoram | Daily Trojan

Dogs are the only species with such an obvious ability to know when they have upset humans, and feel bad about it — or, at least, to act as if they feel guilty. All dog owners are familiar with this: the sad face all teary and droopy-eyed, the tail between the legs and the apologetic whine.

In last month’s Scientific American Mind, the article “The Ethical Dog” discusses research showing that dogs really can tell right from wrong — that they truly know how to play fair.

Canids, including the house dog and undomesticated species like wolves and coyotes, actually give each other apologies. For example, when a dog accidentally bites another too hard during playtime, the guilty one will bow like a monk, stretching his paws out in front of him — a sign that he is sorry and would like to keep playing, according to the article’s authors, Marc Bekoff and Jessica Pierce. Dogs who don’t play fair are quickly ostracized by others.

The article further discusses findings that canids often roll onto their backs and let weaker dogs overpower them while they’re playing, allowing members of a pack to bond and ensuring that every dog gets to have some fun regardless of its size or strength.

Researchers have also shown that dogs, like humans, feel jealousy. In a 2008 University of Vienna study, trained dogs happily shook hands with experimenters without receiving a treat. But if experiments gave another dog a treat for doing the same thing, the original dog, having witnessed this, would cease to cooperate as though fed up with the injustice of the situation.

It is unclear why a blatant sense of right and wrong is limited to humans, canids and a few other species, but it does explain why humans and dogs get along so well. Clearly, we look for companions who are similar to us.

Even the popular belief that we purchase dogs that look like us has proved to be true. Last year, researchers at Bath Spa University in Britain asked subjects to pair pictures of humans with one of three different dog breeds — to guess which breed each person owned. The matches were right 50 to 60 percent of the time. They would have been correct only 30 percent of the time if it had been up to random selection, a Scientific American article last April pointed out.

So perhaps dog owners — especially in Los Angeles — are a bit narcissistic.

According to the Los Angeles Times data desk, the Chihuahua is the most common breed in the county, followed by Labrador retrievers, German shepherds, American pit bull terriers, poodles, cocker spaniels and then chow chows. Given what we now know about the tendencies of dog owners to purchase dogs that look like them, does this mean that a majority of L.A. residents look like Chihuahuas?

Let’s keep an eye out.  But for now, let’s agree that although our obsession with dogs might be a little vain, it is also a reflection of our empathy — the inability of USC students, for example, to let a stray dog stay stray.  We can’t help loving an animal who reciprocates that affection — a pet who cares about our desires and understands us, sort of.

Jean Guerrero is a senior majoring in print journalism. Her column “Scientastical” runs Mondays.