… but they can't help it?
There are a lot of posts that contain reference to favoritism within families and the resentment it causes… especially at Christmastime.
I am from a family of five siblings... four of us have always suspected that the other (oldest daughter) was the favorite. I never resented this as our parents were very good to all of us. They couldn't help it if they felt more affection towards my sister. And in my mum's culture there is a sort of tradition of the "precious first daughter" — and she accordingly received all the family heirlooms.
So am I right in thinking parents always do have a favorite child—whether it's openly acknowledged or not?