[smolder]

Acknowledging substantial differences in people is typically just left as an exercise for the reader, because everyone understands that part from their formative years, implicitly. The part people don't implicitly understand is how their powerful but imperfect approximation-machine brains lead them to treat others unfairly based on differences that are immaterial to a given context. That's why it's taught about.

I think maybe the term "unconscious bias" is misaligned with its use, because the fact is we have lots of biases we don't actively think about, and most of those are useful, not harmful. It's specifically the unconscious biases that are unfair to others that we need to beware.

Unconscious bias is innate to the way we think, it's real, and it's sort of measurable in a way. There's a test called an "implicit association test" where you categorize words as quickly as possible into one or the other group of categories. It attempts to measure the relatedness of categories within a group through the response time of the testee as they sort words. It's something a junior programmer can code up themselves in a day, and having taken the test in good faith and seen the results, I believe it does peak under the hood of how we think to some extent, revealing unconscious biases.