Re: 20 years, near enough...
I agree that I have seen much more of the positive bias than the negative. In fact, since I hire people, I'm subject to it myself.
The reason we have no women in the team currently is because none applied in the latest hiring round. Not that none were suitable, but none applied. The last time one did apply, she was hired almost before she got out of the room. Not because she had certain bits I lacked, but because she was (or seemed to be, based on the interview and later proved by performance) really, really good (thanks, Valentina).
If a white guy had applied who seemed as good - I mean exactly equally as good - I would still have hired the lady as it meant the team would be more diverse. That's bias. I can live with it. The only other way of differentiating would be to toss a coin. That's not generally accepted as solid business practice. Except if you're a trader.
As for colour - something I have gone through various iterations of describing and find most of them ridiculous and prejudiced when Eddie Murphy can use a term which, from me, would be considered insulting - we don't have any Chinese people. Now, that is one of the largest groups on the planet. Am I being discriminatory? Not if no-one applies. I can't hire people who aren't there.