Politically incorrect (but possibly scientifically correct) story of the day: "The high intelligence of Ashkenazi Jews may be a result of their persecuted past."

The argument is that Ashkenazi Jews are more intelligent than the norm (a good thing) for reasons that are also linked to their increased incidence of various neurological diseases such as Tay-Sachs and Gaucher's disease (a bad thing).

The proposed natural selection mechanism is similar to that which causes people of West African descent to be more resistant to malaria (a good thing), yet also gives rise to sickle-cell disease (a bad thing) - namely a mutant gene which is beneficial if a person has one copy, but detrimental if a person has two copies.

At this point, I regard this theory as speculative but plausible. But as the article points out, it is a partially testable hypothesis.