Domestic dogs show many adaptations to living closely with humans, but they do not seem to reciprocate food-giving, according to an Austrian study published in the open-access journal PLOS ONE.
Researchers at the University of Veterinary Medicine in Vienna trained 37 domestic dogs to operate a food dispenser by pressing a button, before separating the button and dispenser in separate enclosures.
In the first stage, dogs were paired with two unfamiliar humans one at a time. One human partner was helpful—pressing their button to dispense food in the dog’s enclosure—and one was unhelpful.
The researchers also reversed the set-up, with a button in the dog’s enclosure that operated a food dispenser in the human’s enclosure.
They found no significant differences in the dogs’ tendency to press the button for helpful or unhelpful human partners, and the human’s behaviour in the first stage did not affect the dog’s behaviour towards them in free interaction sessions after the trials.
Previous studies have demonstrated that dogs are capable of directing helpful behaviours towards other dogs that have helped them previously—a behaviour known as reciprocal altruism—and research suggests dogs are also able to distinguish between cooperative and uncooperative humans.
However, the present study failed to find evidence that dogs can combine these capabilities to reciprocate help from humans. This finding may reflect a lack of ability or inclination among dogs to reciprocate, or the experimental design may not have detected it.