“Some say dogs are the new children, while others find this idea outrageous,” said Enikő Kubinyi, head of the Department of Ethology at Eötvös Loránd University and sole author of the paper, in a statement. “Pope Francis, for example, has called it selfish for childless people to pamper pets.”

Nevertheless, it does seem like that’s the trend lately – at least superficially. “Some studies suggest that dog owners indeed have more negative views of motherhood, and mothers who own dogs find parenting more burdensome, which could reduce their willingness to have more children,” Kubinyi explained. “In some cases, dogs may even harm romantic relationships.” 

“But that’s only one side of the story,” she added. According to Kubinyi, dogs aren’t replacing family members so much as they are joining them – or in some cases, even facilitating them. Owning a dog, after all, means taking them for walks; go to a dog park with little Fido or Fifi and you’re likely to meet other humans with at least one thing in common with you. Interacting with those humans may lead to other, newer humans later on, too: “Women […] tend to find men with dogs more attractive, which could increase the chances of fatherhood,” Kubinyi pointed out, while “some couples see their pet as a ‘practice child’, a preparatory step toward starting a family.”

Overall, she added, “families with children are more likely to own dogs” – so perhaps these four-legged rascals aren’t the enemy of family life they initially seem. But in that case, what’s the link?

“The number of children is not declining because the number of dogs is increasing,” Kubinyi explained, “but the same trend lies behind both phenomena: the transformation of social networks.”

Basically, she says, the problem is our human gregariousness. We’re extremely social, but in the modern world, our communities are increasingly fractured and our lives isolated. Even when we do have families, they tend to be at best nuclear units – a very modern invention, historically speaking. “Humans evolved to engage in so-called cooperative breeding, where childcare duties were shared within the community,” Kubinyi explained, “but in modern societies, these support networks have broken down.”

The problem is, we want to be social; we want to have friends and family; to help with childrearing and foster community ties. But we can’t – so we get a dog. 

“My concept, referred to as the companion animal, or more specifically, the companion dog runaway theory, suggests that the popularity of dogs is rooted in biological evolutionary causes, but it has culturally escalated, ‘run away’,” Kubinyi said. “The caregiving instinct and the need for social support are genetically encoded in human behavior, but these drives have shifted toward companion animals because human relationships are often damaged or absent.”

So direct is this link that we may have even selectively bred our dogs to more closely resemble human children – think the round, flat faces of pugs, for example, or the squat proportions of miniature dachshunds. It’s actually a problem; despite claiming to love these animals, we’re now at the point where many live with chronic health problems for purely aesthetic reasons – we want a cute lil pug to feel maternal over, so we ignore the fact that their lives are uncomfortable and often cut short due to breathing problems from their too-short snout.

Other than that, however it’s hard to say that more people owning dogs is a problem exactly – rather, it’s a symptom of something much more insidious: widespread and crushing social isolation. 

“Dog ownership is a wonderful thing when it connects people rather than isolates them,” Kubinyi said.

But “we need to strengthen family-based social support systems,” she added, “and reduce social isolation.”

The study is published in the journal Current Directions in Psychological Science.