We judge people in areas where we're vulnerable to shame, especially picking folks who are doing worse than we're doing. If I feel good about my parenting, I have no interest in judging other people's choices. If I feel good about my body, I don't go around making fun of other people's weight or appearance. We're hard on each other because we're using each other as a launching pad out of our own perceived deficiency.
Daring Greatly: How the Courage to Be Vulnerable Transforms the Way We Live, Love, Parent, and Lead (ed. Penguin, 2012) - ISBN: 9781101594995