"PHILOSOPHICALLY SPEAKING...":

We discriminate all the time. But what is -- and is not -- ethically wrong discrimination? This piece from Philosophy Now (UK) tries to tease apart various aspects of discrimination:

"The concept of discrimination plays roughly the same role in public debate as the concept of terrorism. In just the same way as disliked militants are often condemned as ‘terrorists’, so disliked policies that differentiate among people are often condemned as ‘discrimination’. Those charges have deep rhetorical power. However, both concepts remain woefully unanalyzed. In this article I want to analyze the concept of discrimination: what it is, and what it isn’t.

"Differentiating among people on account of their group membership, disadvantaging some and not others, is not the problem with discrimination. We don’t discriminate against criminals by burdening them with jail. It is when disadvantages are unjustly imposed because of group membership that differentiation between groups is morally objectionable. This is what we call discrimination. Intentionally disadvantaging innocent people merely because of their group membership is the clearest form of discrimination. ... Doing so strikes at the core of how we think people should be treated. Basic respect for persons entails regarding them as individuals with a right to equal consideration, not just judging them according to others with whom they happen to be grouped. So it might seem that disadvantaging someone for that reason is necessarily wrong.

"We sometimes do intentionally disadvantage innocent people based solely on group membership, in cases where it does not seem wrong to do so. Airline pilots must retire at a certain age. You must be at least eighteen to vote. When one can get married, drink alcohol, join the military, or sign contracts, are similarly restricted. Insurance rates are established by group membership, not by individual characteristics. Of course, these are not the sort of groups commonly recognized as being victims of discrimination. But the salient point is that sometimes there are good reasons to sort and burden people merely because of their group membership. So how do we tell when group membership is a good reason to burden someone, and when it isn’t? Take ten year olds. Not all ten year olds lack the maturity, judgment and experience to drive or vote, but the odds are that any individual among them does. It’s a matter of probabilities. Given that we can’t easily test every ten year old, restricting their rights solely on account of their age seems reasonable. So there is a plausible connection in this case between group membership and why a particular burden is imposed. By contrast, if someone’s group membership is irrelevant to why they’re being disadvantaged, that seems a bad reason. If a bus company refuses to hire black people just because they’re black, this is a bad reason because skin color is irrelevant to bus driving. Gender, race, religion, sexual orientation, and national origin, are all similarly irrelevant to bus driving, too. ...

"The real issue for discriminators is whether the disadvantages they impose on account of group membership are warranted; and that turns on the validity of their beliefs about the target group. But what if the disadvantage is based on statistically verifiable facts? Employers favor non-smokers because they are sick less often than smokers; low income drug addicts are more liable to be petty criminals; skin-heads are more prone to violence; the guy with the rebel flag on his pickup truck is more likely to be a racist; people who drive Priuses are more likely to be political liberals; and so on. With stereotypes which have some basis in the facts, the odds are that any individual in the group will have or lack the trait in question. Most women lack the upper body strength to be firefighters. But some do have it. Most ten-year-olds are not capable of being good drivers. But some are. If we disadvantage someone because of a statistically-correct group norm, but who nevertheless is an exception to the norm, we treat that person unfairly. That person does not deserve the burden we impose, even if others in the group do. However, this is different from imposing burdens on individuals because of false beliefs or incorrect judgments about the group. If we disadvantage someone who is an exception in a stereotype with some basis in fact, it seems to me not discriminatory. It is unfair; and we should try to address unfairness if we can. But not all unfairness counts as discrimination. Discrimination is a particular kind of unfairness, which turns on imposing burdens because of factually misinformed stereotypes."
philosophynow.org/issues/135/The_Ethics_of_Discrimination