> > I'm pretty sure that if you run statistics, you would find out that people from poor neighborhoods are more likely to be criminals, violent, less educated, less intelligent.

> The problem I have with this is that it's a hunch that sounds reasonable, but there's no data to support the claim.

I would bet that there is data to suggest that "people from poor neighborhoods are more likely to be criminals, violent, less educated, less intelligent", and even data to suggest the other inferences tomp brought up.

However, the vast majority of people are not "criminals", at least in the habitual sense, and the vast majority of people from the 'hood are also not "criminals".

"When the incidence, the proportion of those who [are criminals], is lower than the [proportion of people from the 'hood who are not criminals], even tests that have a very low chance of giving a false positive in an individual case will give more false than true positives overall."