When American soldiers were given mental tests during the First World War, those men of German ancestry scored higher than those of Irish ancestry, who scored higher than those who were Jewish. Mental test pioneer Carl Brigham said that the army mental test results tended to "disprove the popular belief that the Jew is highly intelligent."
An alternative explanation is that most German immigrants came to the United States decades before most Irish immigrants, who came here decades before most Jewish immigrants. Years later, Brigham admitted that many of the more recent immigrants grew up in homes where English was not the spoken language and that his earlier conclusions were, in his own words, "without foundation."
By this time, Jews were scoring above the national average on mental tests, instead of below. Disparities among groups are not set in stone, in this or in many other things. But blanket equality of outcomes is seldom seen at any given time either, whether in work skills or rates of alcoholism or other differences among the various groups lumped together as "whites."
Why then do statistical differences between blacks and whites set off such dogmatic assertions -- and "disparate impact" lawsuits -- when it is common for different groups to meet employment or other standards to different degrees?
One reason is that "disparate impact" lawsuits require nothing more than statistical differences to lead to verdicts, or out of court settlements, in the millions of dollars. And the reason that is so is that so many people have bought the unsubstantiated assumption that there is something strange and sinister when different peoples have different achievements.
Centuries of recorded history say otherwise. But who cares about history anymore? Certainly not as much as they care about the millions of dollars available from "disparate impact" lawsuits.