I understand that favouritism happens all the time, in the sense that we all have preferences - that's why we have best friends, partners, choose particular pets over others, paint our houses certain colours etc. But favouritist treatment can be somewhat abusive when it comes to the family and pets. Yes, a parent might get on particularly well personality/hobby-wise with one of their kids and not so much with the others, but it's when the parent chooses to act on that favouritism that it's unfair and wrong, and THAT I cannot fathom. We've been taught that we must show equal love to all our family, and that's very logical as the psychological effects of favouritism towards one family member over another can be devastating. Unfair treatment is really not excusable for a parent. If you don't want to suck it up and show equal care, affection and attention towards all of your children, then you probably should not have any as fair treatment of them is a basic responsibility, in my opinion anyway. And I agree that it should be the same for pets. Don't buy pets you're going to neglect.