We can regulate a dog’s body budget, and dogs can regulate ours in turn. (I wouldn’t be surprised if dogs and their human owners even synchronize their heart rates, the way close humans do for each other.) We also probably selected for dogs with eyes that we perceive as expressive and facial muscles that move easily to serve as a canvas upon which we can paint complex mental states. We love dogs so much that we bred them to love us back, or at least to see them as loving us.
