Dogs have evolved to be sensitive to oxytocin, say researchers.
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Does your dog obey your every command? It might be thanks to the bonding hormone oxytocin.
A new Australian study has found that dogs were better at following cues to find a hidden treat after they were given oxytocin.
The findings provide the best clues yet on how dogs might have evolved to be humans' best friend, and could help pave the way for breeding dogs that respond even better to human cues, said researcher Jessica Oliva, who carried out the research as part of her PhD in biological sciences at Monash University.
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In humans, oxytocin is well known as a hormone that helps mother and baby bond, and as a chemical in the brain that increases the ability of people to understand emotions and solve social problems. However, there is also mounting evidence that oxytocin is involved in bonding between humans and dogs.
For example, said Oliva, patting and talking to a dog for just three minutes has been found to increase oxytocin levels in the blood stream of both human and dog. And studies have also shown that the closer a human feels to a dog, the more oxytocin appears in the human's urine.
"So that really seemed to suggest that oxytocin is involved in feelings of closeness to your dog," said Oliva.
But measuring levels of oxytocin in the blood is not necessarily indicative of what's happening in the brain, she said.
Nasal spray
In their study, Oliva and colleagues looked at the impact of oxytocin on dogs' ability to use human cues to pick which of two bowls contained a hidden treat. 31 male and 31 female pet dogs were tested twice after being given oxytocin or a saline placebo, and given scores out of ten for their performance. Importantly, in this study, oxytocin was administered to dogs via a nasal spray that ensured it would easily get into the brain.
The results, published in the journal Animal Cognition , show that animals given oxytocin outperformed those not given the chemical. Moreover, this improvement in performance was still evident 15 days after the oxytocin was given.
"This told us that oxytocin is definitely involved in a dog's ability to use human cues."
Dog evolution
Oliva said previous research has shown that dogs are better than their wolf ancestors at using non-verbal human cues like pointing to pick up treats. This is the case even with wolves that are highly socialised and hand-reared by humans.
"So my hypothesis is that over the course of domestication, something happened within the dog's brain that allowed them to understand human social cues."
Her suggestion is that oxytocin enables the bond between dog and human. Oliva said the next step would be to do exactly the same experiment in wolves.
"That would really tell us more about evolution," she said.
Oliva said some dogs in the experiment were better than others at the task.
"Some were at chance level, some were really good."
She is currently looking at whether there is a genetic difference in the oxytocin receptor gene in the better-performing dogs. That could lead to selective breeding of dogs especially guide dogs, military dogs, or customs dogs, said Oliva.
This article originally appeared on ABC Science Online .