In a way, yes. The inability to diverge from current strongly-held beliefs and accept opposing fact-based opinions is a strong indication of groupthink. Even worse, when you would rather destroy relationships over it – which also shows the level of severity of your sister's groupthink mentality. This is why I don't vote, or take what politicians and corporate leaders claim to believe in, seriously. It's also why I don't follow any religious beliefs (which still causes some minor issues to this day), just my own personal moral code, that almost all max-normies disagree with.

Goodnight. Keep stacking.