This seems like pretty flawed reasoning. What you are describing is not a prior but a posterior - the distribution after the observed data has been taken into

This seems like pretty flawed reasoning. What you are describing is not a prior but a posterior - the distribution after the observed data has been taken into account. If anything the prior can help make you less racist by incorporating the knowledge that immutable characteristics are not good indicators of danger/not danger. The thing is though, even if you are told race doesn't matter through a prior, if you observe a strong correlation over many instances it's going to be hard to ignore that regardless of your prior (what you are told). While it may not be a causal relationship, it may still be a good predictor.