The narrowest of victories: Jews 110, Episcopalians 109: Using the vocabulary test data from the General Social Survey, I estimated the IQs for American Jews and white Episcopalians (Es) (about 10% of Es are black). Setting the American white average at 100, Js come in at 110, which doesn't surprise me, and Es weigh in at 109, which makes them surprisingly similar to Jews. My Jewish estimate is lower than La Griffe's, which is 116. One reason mine is lower might be that La Griffe studied Ashkenazi Jews, and while most Jews are in the GSS sample are also Ashkenazi, 150,000 Jewish Americans are Sephardic--a group with a lower average IQ.
Studies of Jewish IQ have also noted more variation than in general populations, but according to the GSS, the standard deviation is only slightly larger than that of all white Americans (or Es).