The bond between humans and their pet dogs shares striking similarities between parent-child relationships in humans, according to a new study, which suggests that pet dogs enter deep relationships with their owners.

Scientists at the University of Veterinary Medicine, Vienna (Vetmeduni Vienna) report dogs are so well-adapted to living with humans that in many cases the interspecies relationship replaces the dogs' conspecific relationship with other canines.

Dog owners assume the role of the dogs' main social partner and the relationship turns out to be highly similar to the deep connection between young children and their parents, according to a report from Vetmeduni Vienna.

In parent-child bonding, researchers have documented a concept called the "secure base effect," where infants rely on their caregivers as a secure base when it comes to interacting with the environment. Until recently, the concept had not been explored in humans' canine companions.

Vetmeduni Vienna researcher Lisa Horn examined the behavior of dogs and their owners under three conditions which she called "absent owner," "silent owner" and "encouraging owner."

In Horn's experiment, the dogs were given a food reward by manipulating interactive dog toys. Horn found that under the "absent owner" condition dogs were much less interested in working for food. But the mere presence of the dog's owner led to greater motivation to work for treats, regardless of whether the owner was "silent" or "encouraging."

In a follow-up experiment, Horn and her colleagues tested dogs' motivation to work for food in the presence of a stranger instead of their owner. They observed the dogs hardly interacting with the stranger and being only marginally more interested in trying to get the food than when the stranger was not there. But the dogs were demonstrably more motivated to work for food in the presence of their owner, which led Horn to conclude that the owner's presence is important for the dog to behave in a confident manner.

A comparable result has been documented human children when they were confronted with a problem-solving task: those children that were able to use their mother as a secure base were found to be more motivated and persistent in solving the task. While humans tend to outgrow the need for a secure base, dogs seem to be unique by retaining the behavior into adulthood, the researchers report.

"One of the things that really surprised us is that adult dogs behave towards their caregivers like human children do," Horn said in a statement. "It will be really interesting to try to find out how this behavior evolved in the dogs with direct comparisons."

Vetmeduni Vienna reports the study is the first to present evidence for the similarity between the "secure base effects" found in dog-owner and child-caregiver relationships.

The research is published in the journal PLOS ONE.