It seems to me that creating and using cultural signals that allow us to differentiate between the in group and the out, is a fundamental part of human culture.

It seems to me that creating and using cultural signals that allow us to differentiate between the in group and the out, is a fundamental part of human culture. There's no culture where it doesn't exist, and as soon as we remove one set of culture signals another quickly replaces it. As a sibling post pointed out, in workplaces with suits, people differentiate by cut of suit. So the answer isn't to try rid ourselves of cultural signals, they'll just get replaced with new ones. The answer imo is to work at being aware of the signals we have and the biases they give us. That's hard, much harder that simply removing the existing signals, but resisting hardwired human nature is hard.