I don't think dogs necessarily simply work to make people happy. But I do think that some dogs view a happy handler as being of slightly higher value than some other dogs do, if that makes sense. Just observing my own dogs... Ripley is my most people pleasing dog. He tries very hard to do right and making me happy is reward enough for him. He definitely loves the added bonus of a food reward or toy, but he's pretty happy to just make me happy. Dance also likes to please me, but she thinks a lot more and would take a toy or a food reward over simply pleasing me anyday. But if those are not available, she's happy enough to just do something for praise or because I said so. Just not quite as enthusiastically/frantically as she'd be willing to do for another reward. Keira is the least people pleasing dog I've ever had. She certainly doesn't like to do wrong, but she doesn't go out of her way to do right or please us in any way either. If there is no food involved, she has no qualms about thinking of blowing you off a lot of times or giving you a look like a snotty kid full of attitude. I swear she'd do nothing but roll her eyes at me constantly if she were human, haha. She does what she's told because that's what she knows is expected, but she does it in an entirely different way than the other two.