Ladling out too much guilt and shame. They are not motivational forces for me to be “better”, in fact quite the opposite was true
Also telling me that I wasn’t good at math. Sure, it wasn’t my strongest subject. But don’t tell a kid that they will never ever succeed at a subject due to some inherent shortcomings
Playing favourites. My brother was allowed to grow marijuana as an “experiment “ by my very straight laced and anti drug parents. In fact they were enthusiastically supportive. Not so much for me. That’s just one example. Basically he could have pissed in my face and our folks would have blamed me. They always made me feel like I was inadequate because I wasn’t like him. My brother is a classic grandiose narcissist.