A recurring observation in the discussion based on IQ estimates for American Jews (among others) in the GSS was that the chosen ones, to quote Sid “come across as above average in intelligence today, but not terrifyingly brilliant the way they did 100 years ago”.
The commenters here are invaluable. The following graph shows the IQ advantage Jews enjoy over non-Hispanic white gentiles by decade when the surveys were conducted. To avoid language confounding, responses are restricted to those born in the US. IQ estimates are based on Wordsum scores with a mean white gentile of 100 and a standard deviation of 15 (N = 9,599):
The most obvious reason for this move towards convergence is out-marriage. The overall intermarriage rate for Jews in the US is 58%. It’s an astounding 71% among non-Orthodox Jews. With fertility below replacement, most Jews marrying non-Jews, and little Jewish immigration into the US, the 2% is on its way to becoming the 1% is on its way to becoming the 0.X%.
Here are the converted IQ estimates for Jews and white gentiles that were used to construct the preceding table:
GSS variables used: WORDSUM, BORN(1), ETHNIC(2,6-11,13-15,18,19,21,23-27,36), RELIG(1-2,4-13)(3), YEAR(1980-1989)(1990-1999)(2000-2009)(2010-2016)