I think our feelings toward our pets somehow invoke the brain modules we use in relating to our babies. We have bred dogs and cats to look more baby-like and to act more like puppies and kittens. We baby talk them. We forgive them their mistakes, especially their messes. And we get from them some of the reward that evolution has primed us to get from raising offspring.
The argument advanced by this psychologist, Suzanne Phillips, is that we should treat our spouses more like we treat our pets. I regard this as a bizarre contention, because our whole relationship with pets, and babies, is based on a gigantic inequality. I do agree that greeting each other every time we come home, as dogs insist on being greeted, is probably a good thing for couples to practice, and I think people should in general practice being more forgiving and less irritable toward each other. Beyond that, the notion is hooey. As one commenter put it:
The difference is that pets have no real power to hurt us. They can frustrate us, and they can certainly damage our property. But for the most part, we don’t depend on pets for anything. They can’t hurt our feelings. The stakes between people are much higher. The needs are much more profound. Although we should all treat our spouses better, this comparison is misleading.I am not really sure that the needs we want pets (or babies) to fill are "less profound," since pet keeping is more universal among humans than marriage. But they are certainly very different.