They only do what People Like Them do

And they are incredibly sensitive in determining who these people are.

This is what people have always been like - they identify with people like them, who speak the same language, and have the same mores. Who have the same culture.

The Industrial Revolution, followed by the Computer Revolution - changed everything completely,

But people still have no difficulty determining what people are in which groups - and if they are part of them.

This is part of their Entertainment - going to Movies where Social Roles are complicated - and watching people cope with this confusion.