Tuesday, July 25, 2006

The "Flynn effect" observed in GSS data: Now we can't get too excited about measuring IQ with 10 vocabulary questions, but what the heck--this is a blog, not Intelligence. The GSS has been asking vocab questions since the early 70s, so I averaged the number correct out of 10 for blacks and whites. Here they are:

Blacks
70s 4.59
80s 4.69
90s 4.97
00s 5.15

Whites
70s 6.17
80s 6.14
90s 6.33
00s 6.39

So we see increases for both groups, but it's larger for blacks. While whites increased 4% over the period, black averages rose 13%. One bit of evidence that this measure is not just nonsense is that we see the consistent, large gap between blacks and whites, like a guzillion IQ studies have shown. And there has been some narrowing of the gap over the period.

Now it's possible that the words got easier--I don't know if they used the same words every year, and it's too late for me to look the damn thing up. I will say that if the test got easier, then why did whites only improve between the 80s and 90s while blacks improved every decade? And why did blacks improve more? I thought as people age, they might gradually pick up more words, and while it's true that mean white age rose 2.6 years over the period, blacks dropped .4 of a year. And whites aged gradually from the early 70s until now, while their vocabs only improved between the 80s and 90s. Comments are appreciated, and maybe I'll try to see what explains the increase later.

Black-white differences in glaucoma

Glaucoma is a progressive condition caused by a combination of genetic and environmental factors and is the leading cause of irreversible bl...