Scientists don't "know" any such thing! This is merely wishful thinking - something that the Hudson Institute specializes in.
First, any student anatomist can identify a person's race by a variety of physical features. Forensic pathologists can often identify a person's race by a single tooth or a few bones.
Second, when it comes to genes, it is much more honest to say that based on the current state of knowledge scientists cannot identify a person's race by analyzing his genes. To point out that there is very little genetic diversity between humans of all races does not mean there aren't meaningful differences between the races. Sometimes, a single genetic defect can make a HUGE difference in a person's wellbeing. Or, look at it this way: Chimps and humans share over 98% of their genetic makeup. Clearly, that 2% makes a LOT of difference.
What bothers me most about this pseudo-scientific hokum that tries to say there are no differences between the races is that it begs the question: Why the disparity in behavior and outcomes? If we are all the same, then why do blacks - 13% of the population - make up only 2% of corporate executives and commit 50% of the crime? Why has black student achievement lagged that of whites at the same rate for nearly 30 years - ever since the government has measured it - despite $billions of government money? If we are all the same - THEN WHITE PEOPLE MUST BE RACIST OPPRESSORS WHO WILL NOT/CANNOT CHANGE. If you were black and believed that the only reason you were not doing as well as whites was because they have been keeping you down for hundreds of years and show no sign of every stopping, how long would YOU put up with this situation?
If you accept evolution, then you know that different human populations have evolved in wildly different environments under different selective pressures for tens of thousands of years. During this time average height, weight, bone structure, skin color, disease resistance, and virtually every other gene frequency have changed among those different human populations. In fact, the odds of any single human characterisitc being invariant after tens of thousands of years of evolution for every single different human populations is so astronomically slim as to not even be worth considering.
Look, Asians are shorter than Blacks but we don't spend billions of dollars on childhood nutrition programs trying to make Asians as tall as Blacks. Like it or not there are genetic differences between the races that cannot be changed. Now the individual variation is huge and normally these racial differences are not a big deal. But when you insist on categorizing people by race and compiling statistics, then these average differences are going to emerge very clearly. Lower intellectual performance by blacks does not imply racist white teachers any more than lower height by asians implies racism. It's time we truly accepted diversity. People are not the same, and we would be alot better off if we opened our eyes, accepted reality and dealt with it, rather than just believing what makes us feel good.
I bring this up not because I like to feel my race is superior to any other, it really doesn't matter, I'm an individual. But what does infuriate me is that me and all members of my race are constantly demonized by the media and targetted for discrimination because we perform too well compared to other groups. The implication is that the only reason I perform better is due to racism and preferences and that I don't really deserve what I get. I find this attitude highly racist and prejudicial. It's time to stop blaming whites for minority underperformance.
Because their culture is severely messed up. You may also want to look at the comparative differences when you seperate Caribean blacks from American blacks.
Why has black student achievement lagged that of whites at the same rate for nearly 30 years - ever since the government has measured it - despite $billions of government money?
Because American black culture has picked up anti-intellectualism as part of it? Because those liberal programs that cost billions did nothing to address the underlying cultural problem? You are away that students in Harlem were able to rank second in the city before all those billions of dollars started helping them, right?