In the 1950s, the correlation between Wechsler global IQ and years of education among American adults was a potent 0.7 (roughly as high as the correlation between two different IQ tests) but by the late 1970s it had sunk to 0.57, where it remained through the 1990s and presumably today.His post on the relationship between IQ and education made me wonder if the GSS might shed some light on the presumption he makes.
Restricting respondents to those born in the US and aged 25-39 at the time of their participation in the survey, the correlation between mean years of education and mean wordsum scores by decade is as follows:
1970s -- .56
1980s -- .53
1990s -- .46
2000s -- .42
2010s -- .42
Although the earliest year for which both educational attainment and wordsum scores are available is 1978, the relationship between years of education and wordsum scores are virtually identical to the correlation between the Wecshler IQ test and years of education reported by Pumpkin Person (.56 and .57, respectively), lending credibility to the rest of the results.
This suggests that rather than holding steady since the seventies, the relationship between years of education and intelligence has continued to weaken and is now just over half of what it was in the 1950s.
As more and more people obtain degrees, a degree--generically, the correlative power of a specific degree will vary based on what area of study the degree is in--will tend to signal less and less about the cognitive capacities of people who have them.
Steve Sailer has pointed out multiple times in various contexts that the easiest way to reduce disparities in accomplishments is to water down the requirements necessary to enjoy said accomplishments. If a college degree becomes as common as 'graduating' from elementary school, the correlation between a degree and IQ will approach zero.
That is the direction that this age of educational romanticism will continue to drive us in if it doesn't end up on the side of the road because of a blown student loan gasket. The trend shows up in mean IQ* by decade among native-born college graduates under the age of 40. As the percentage of people who graduate college increases, the IQ of the average college graduate compensatorialy decreases:
1970s -- 113.7
1980s -- 110.8
1990s -- 106.6
2000s -- 104.4
2010s -- 104.3
Parenthetically, Inductivist pointed out this latter trend years ago.
* Computed by assuming the mean wordsum score of non-Hispanic whites to be the equivalent of an IQ of 100 with a standard deviation of 15.
GSS variables used: EDUC(16-20), YEAR, WORDSUM, BORN(1), AGE