In a previous post, I used GSS vocabulary data to show a 10 point improvement in IQ among Mexican-Americans over the past four decades. An increase from 85 and 95 is striking, but I didn't take the time to see if the change is statistically significant.
Setting the white IQ at 100, here are the means by decade for people born in America who are of Mexican descent. Sample sizes are shown in parentheses:
Seventies 85.4 (12)
Eighties 85.6 (106)
Nineties 91.7* (140)
Two-Thousands 94.1* (182)
*significantly higher than the 80s mean
The means for the Nineties and the Two-Thousands are significantly higher than the Eighties' mean but do not differ significantly from each other. The estimate for the past decade is a bit lower than in my last analysis; this is due to the addition of 2008 data. (The mean for 2010 is 91.6, n = 46.)
A mean in the low nineties is not inconsistent with published studies. The low mean of 85 observed in the 1970s and 80s might be due to a lower average level of education. The average respondent in a GSS survey is in his mid-40s which means that if he participated in a survey in the 70s or 80s, he would have gone to school in the 1930s and 40s.