Girl playing with a dog

One theory is that play helps puppies learn motor skills. If you look at what dogs do in play, they chase each other, roll around on the floor in play fights, mount, pick up objects with their mouth, and tug, bite or shake them. Puppies learn how hard they can bite their playmates (acquired bite inhibition), and play bow to keep the play going for longer. Through these play activities, they are learning real skills relevant to how to move their bodies, acquire food, and defend themselves in fights. The scientists say this theory explains a lot of things about play but is not the full story.

Another theory is that play is training for unexpected things to happen: it’s through play that dogs know how to right their bodies when knocked off balance and how to cope when something surprising startles them. According to this theory, changes in the brain and in hormone levels during play help dogs learn how to cope with real-life stressors. This theory explains the fact that dogs like new toys but are cautious of new things that aren’t toys. It also explains the way dogs self-handicap during play and put themselves at a disadvantage; this can be seen as practicing behavior they may need later on as a way to defuse real aggression. But again, this theory only explains some aspects of play.