By Mary Jo DiLonardo │TreeHugger│5 min

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Your dog loves you, but that doesn’t mean he’ll offer you any food. That’s even if you’ve given him some first.

In a new study, researchers gave pet dogs the chance to return the favor when people offered them kibble, but dogs didn’t jump at the chance to reciprocate.

Earlier studies have found dogs will give and take when they get help from other canines, so researchers were curious if they’d do the same for their human companions.

The concept is known as reciprocal altruism or reciprocity, study author Jim McGetrick of the University of Veterinary Medicine in Vienna, tells Treehugger.

“The general idea is nicely captured by the expression ‘you scratch my back, I’ll scratch yours,’ “ says McGetrick. “This is an important concept in the field of social behaviour and evolution as it is one of the primary explanations for the evolution of helping or cooperative behaviour, that is, one may benefit from paying a cost to benefit a social partner because that helpful act may result in that social partner returning a favour in the future.”

The classic form is “direct” reciprocity and that’s where individual A helps individual B and then B helps A. That’s different from “generalized” reciprocity where individual A will help any individual after receiving help from B. And there’s also “indirect” reciprocity where A will help B after watching B help C.

In a previous study, military dogs were paired with other dogs that either would or would not pull a tray in order to provide them with food. Then they had the chance to do the same thing and pull a tray to give those dogs food … or not.

“They provided food more frequently to partners that helped them in the past suggesting ‘direct’ reciprocity,” says McGetrick. “However, when dogs were paired with new partners after receiving food from their previous partners, they also provided food even though they had not been paired with the new partners before, suggesting ‘generalized’ reciprocity i.e. ‘help anyone if helped by someone.’”

But would this give and take translate to people?

Researchers devised an experiment to find out. First, dogs were trained to press a button that would operate a food dispenser. Then they went through a phase of the test where a person they didn’t know either gave them food by pressing the button or didn’t give them food.

Then the setup was reversed so the human had the food dispenser and the dog had control of the button. The dog could choose whether to give food to the human who had been helpful earlier and had given food or to the human who had been unhelpful and didn’t provide food.

There were also two test situations where the dog could press the button when there was no person around. This allowed researchers to see whether the dog was pressing the button because it was simply a learned behavior or because the dog just enjoyed pressing the button.

Researchers performed an additional version of the study, changing some small elements of the design to simplify it in order to make it easier to understand for the dogs. And they also had an interaction session where the dogs spend time with the helpful and the unhelpful person.

But it didn’t seem to matter if the person on the other side of the button had been generous in the past.

“We found that the dogs did not reciprocate in any of the two studies,” McGetrick says. “Also, they did not differentiate between the two partners, as evidenced by a lack of a difference in the time they spent in proximity to each human or how quickly they approached the humans in the interaction session.”

The results were published in the journal PLoS ONE.

Understanding the Results

While a dog lover might be miffed if their dog wouldn’t eagerly offer a treat, researchers aren’t so easily fazed.

“It was difficult to have a clear expectation about what the result would be. Even though dogs are known for their relationship with humans, previous studies investigating whether dogs would behave prosocially towards humans provided mixed results,” McGetrick says.

“In one study, dogs would not provide a familiar or unfamiliar human with food even though dogs were shown to use the same mechanism to provide familiar dogs with food. In contrast, dogs were shown to rescue their owner who was trapped in a box and showing distress. It appears that the behaviour of dogs is very context specific.”

It is surprising, McGetrick points out, that in the earlier, similar study, dogs provided food to other dogs that helped them out but they don’t do the same when humans give them food. He suggests a few possible explanations for the study results.

“First, it is possible that dogs do not reciprocate the help received from humans in food contexts. This might make sense as in their daily lives dogs never need to provide food to humans,” he says.

“Second, as in every animal behaviour study, we cannot ask our subjects what they understood about the task. It is possible that the task was too complex for the dogs and they did not pay attention to the actions of the humans and only focused on the food dispenser and whether food was being delivered.”

This could also explain why they didn’t discriminate between the helpful and the non-helpful person. They might not have noticed that their actions were linked to whether food appeared.

There is hope, dog owners, that your dog might behave differently around you.

“Finally, in our study all the human partners were unfamiliar to the dogs and they were not allowed to communicate with the dogs in any way,” McGetrick says.

“Both familiarity and communication can play an important role in cooperation. We might have obtained different results if the partners were familiar humans or if they were allowed to interact and communicate more naturally with the dogs.”View Article Sources 

1. McGetrick, Jim, et al. “Dogs Fail to Reciprocate the Receipt of Food from a Human in a Food-Giving Task.” PLOS ONE, vol. 16, no. 7, 2021, p. e0253277, doi:10.1371/journal.pone.0253277
2. Gfrerer, Nastassja, and Michael Taborsky. “Working Dogs Cooperate Among one Another by Generalised Reciprocity.” Scientific Reports, vol. 7, no. 1, 2017, doi:10.1038/srep43867