The only "class" I care about is decent folk, regardless of whether they were born rich or poor, regardless of race, regardless of lineage, regardless even of whether they have any intelligence to speak of. Decent people respect the rights of others - their right to life, their right to liberty, their right to property. When possible they'll even go out of their way to help their neighbors.
Yes, it's true that people work together in complex societal relationships - but it's also true that everything ultimately comes down to the decisions of individuals - just as every physical object in the world is ultimately made up of atoms. If individuals refuse to comply with the diktats they receive from others, there can be no tyranny. If they always comply without thinking, tyranny is easy - even the norm.
As for Margaret Thatcher, no doubt she wasn't perfect but she was a far sight wiser than anyone who I have ever heard talk about "class interests".
And if you want to defer to the field of Psychology, don't forget that it was psychologists who provided the intellectual impetus and support for the dehumanization and abuse of pedophiles by governments and populations around the world. It was the lies and incompetence of psychologists (often difficult to distinguish from one another) that provided the official narratives that are used against us. Why do you give the field credit knowing how badly it screwed THAT up?