According to research, it is likely that the culture of keeping pets began thousands of years ago, with our human ancestors capturing young wolves and domesticating them. The reason for adopting these furry predators was probably not for their cute faces, but because they were useful for hunting. Over time, these wolves evolved into a tamer species - dogs. According to a study published in May 2015, this evolution could have been as early as 27,000 years ago. So if we no longer hunt, why keep pets around now?  

John Bradshaw of Bristol University's School of Veterinary Sciences in the UK proposed another pet-culture evolution theory that doesn't hold up so much in the present day, which is that it gave women an opportunity to show that they were good and capable of caring for a helpless mammal. This practice suggested care-giving qualities and demonstrated and nurtured empathetic behavior, said Bradshaw to the BBC. 

Taking care of an animal can be extremely costly, as any pet owner might tell you. Due to cost, other theories suggest that owning a pet is a sign of a person's wealth. In order to properly care for an animal, one needs the resources to take care of themselves and the pet. "There's a lot of history and culture with how we chose to express this desire to look after animals, but basically it is a human instinct that used to be an honest signal of the ability to look after animals," said Bradshaw.

James Serpell, professor of Animal Ethics & Welfare at the University of Pennsylvania, believes that there are still evolutionary benefits even today from keeping pets. Because humans are a social species, he states that we are constantly seeking relationships not just with other humans but with our pets as well. "Humans which lack social support are more vulnerable to disease and infection."

We might think of owning pets as the norm but as Harold Herzog of Western Carolina University states, "We keep pets because other people do because it is "socially contagious," Herzog told an audience at the annual convention for the Association for Psychological Science in New York. "We do have these general predispositions to be attracted to animate things - we have predispositions to find puppies and kittens cute, but that puppy that is so cute in the US can be perceived as a meal in [South] Korea, so what's going on there?"