You're falling into the fallacy of the excluded middle. Just because "black" doesn't tell you everything about a person doesn't mean it can't tell you something useful.
That typical (now there's an overgeneral term!) black woman will have a darker skin color than a typical white woman. She will be less susceptible to sunburn. She is more likely to suffer from certain genetic diseases like sickle cell anemia.
Now, none of these are absolute statements. They are all probabilities. That does not make them useless. If someone comes into the ER with severe pain in their extremities, it is very useful to know that they're black. They may or may not have sickle cell anemia - that can be determined conclusively through a blood test and thorough medical examination. But knowing whether they're likely to is very useful information, because it lets you determine whether it's worth putting in the extra effort to diagnose it conclusively. (Similarly, even if they carry the genetic marker, they might not be having a sickle-cell crisis, and it could be a blood clot or some other medical condition. But it's pretty damn likely.)
It's a fallacy to believe that just because the data you're working with can't tell you everything, it tells you nothing. Rather, you should recognize the limitations of what you know, and use them to determine what else you need to know. Race tells you something. It doesn't tell you a whole lot, because there's a lot of individual variation within a race. But that doesn't mean it tells you nothing, either.
That typical (now there's an overgeneral term!) black woman will have a darker skin color than a typical white woman. She will be less susceptible to sunburn. She is more likely to suffer from certain genetic diseases like sickle cell anemia.
Now, none of these are absolute statements. They are all probabilities. That does not make them useless. If someone comes into the ER with severe pain in their extremities, it is very useful to know that they're black. They may or may not have sickle cell anemia - that can be determined conclusively through a blood test and thorough medical examination. But knowing whether they're likely to is very useful information, because it lets you determine whether it's worth putting in the extra effort to diagnose it conclusively. (Similarly, even if they carry the genetic marker, they might not be having a sickle-cell crisis, and it could be a blood clot or some other medical condition. But it's pretty damn likely.)
It's a fallacy to believe that just because the data you're working with can't tell you everything, it tells you nothing. Rather, you should recognize the limitations of what you know, and use them to determine what else you need to know. Race tells you something. It doesn't tell you a whole lot, because there's a lot of individual variation within a race. But that doesn't mean it tells you nothing, either.