The Linux Foundation's report on diversity, equity, and inclusionin open source

In this case, the in-group explicitly identifies itself as "the group of reason and knowledge." This is not just wrong, but dangerous, because it makes it more difficult for the in-group to accept that it is guilty of exactly the same cognitive biases as everybody else (such biases are antithetical to the in-group's identity). Ironically, this makes the in-group even more vulnerable to the in-group/out-group bias that you are describing, as well as a host of other biases that correlate with it. The more "rational" the in-group believes itself to be, the less rationally it will in fact behave.

How do we fix that? Be more humble. Listen more, accept greater uncertainty, and think very long and hard before you contradict or disbelieve somebody else's lived experience. Why do you doubt their experience? Do you think they would lie about it, or do you think they have misinterpreted something? If the latter, remember that intentions are invisible, and mostly irrelevant (the environment is welcoming or unwelcoming as a product of our behavior, not our intentions). Be dispassionate - don't take it personally if someone else points out problems with the in-group. Above all, be kind to people.