Dogs love to play, but they don’t do so for pleasure

Listen together: Play’ is simply a byproduct of the way that young animals grow and develop. A Jack Russell terrier tears in and out of its doggie door, skidding and sliding on a hardwood floor, only to repeat the performance over and over again. A Border collie in the park leaps to catch a ball, runs and drops it back at the owner’s feet with a look of anxious anticipation. There’s no food treat in store for these animals, no pats on the head – they seem to do it out of sheer playful exuberance. But what are they really up to?