A few examples (in approximately increasing order of controversy):
If you proceed anyway...
- Identify knowledge that may be dangerous. Forewarned is forearmed.
- Try to cut dangerous knowledge out of your decision network. Don’t let it influence other beliefs or your actions without your conscious awareness. You can’t succeed completely at this, but it might help.
- Deliberately lower dangerous priors, by acknowledging the possibility that your brain is contaminating your reasoning and then overcompensating, because you know that you’re still too overconfident.
- Spend a disproportionate amount of time seeking contradictory evidence. If believing something could have a great cost to your values, make a commensurately great effort to be right.
- Just don’t do it. It’s not worth it. And if I found out, I’d have to figure out where you live, track you down, and kill you.
Group statistics gives only a prior, and just a few observations of any individual will overwhelm it. And if start discriminating against gays if they have low average intelligence, then you should discriminate even more against low intelligence itself. It is not the gayness that is the important factor in that case, it just has a weak correlation.