Region matters, don't you forget it

Over at Ezra Klein’s weblog his research assistant had a post up on the black-white academic achievement gap by state. This section was of interest:

…Among southern states, the deep South, where one might expect to see the largest gaps, does not stand out, with Alabama and Mississippi doing roughly as well as the Carolinas or Tennessee. Hawaii and West Virginia report the smallest gaps in both surveys. Both have notably small black populations, which provide less opportunity for de facto school segregation.

Why might one expect the largest gaps there? Obviously the history of Southern racial polarization, and the exceptional nature of the subjugation of blacks by whites. But one thing that I have seen in the General Social Survey over the years is that it is in the American South that blacks and whites exhibit the least cultural difference in attitudes and outlook. This should not be that surprising, local culture matters a great deal implicitly in a sense which is only evident once you leave your familiar context.The Second Great Awakening, which reshaped the South religiously as a region where evangelical Protestantism was dominant among the population, influenced both black slaves and non-elite whites disproportionately.

These realities would be less surprising to people if they were more conscious of the patterns in the United States which derive from different streams in Anglo-Saxon folkways, as outlined in books such as Albion’s Seed and The Cousin’s Wars. Going back to educational attainment, the GSS vocabulary test, Wordsum, has the lowest scores in the South for both blacks and whites. On a more fine grained level, let’s look at mean Wordsum score broken down by region and ethnicity. The regions are as defined by the Census divisions. I wanted to look at ethnicity, as well as race. White and black categories are straightforward. British = Scottish, Welsh and English ancestry. Irish might seem to straightforward, but I think it’s pretty obvious that it throws into one category two social-cultural groups, the Catholic Irish and the Scots-Irish. First, here’s a line graph illustrating the variation by region for mean Wordsum score:

I chose a line graph so you could see that all the groups track each other. If you’ve followed my writing over the years you’ll have seen the pattern before; New England is the most academically inclined region, and the Gulf Coast of the Deep South the least. Below is a table with the mean scores by region, broken down by ethnic and racial group.

A quick note: sample sizes for blacks in the Mountain region and New England are very small. So ignore that. Rather, observe that the black-white gap is pretty similar in the Mid Atlantic and the E S Central in a proportional scale (whites do about 20% better), but it is smaller in an absolute sense in the latter case. That’s because whites in that region of the country do rather badly, not that blacks do well.

The correlation between black and white mean values of Wordsum is 0.63, which means that one can predict 40% of the variation in the regional differences of one race by the variation of the other. Here’s a correlation matrix with the ethnic groups:

This is making concrete in a simple statistic what you saw on the line graph; the between regional patterns are significant and transcend ancestry groups (though I suspect that the high correlation between the British and Irish categories in the GSS has to do in large part with the fact that the two overlap a great deal today with intermarriage). Of course you might wonder if this applies to anything else. As I said, it is clear in relation to cultural issues that region matters a lot. Abortion has been one issue with relatively little change over the years in the GSS. The correlation in opinion by region between blacks and whites as to whether women should be able to have an abortion for any reason is about 0.80. Here are the correlations for the ethnic groups:

More plainly, you can see support for abortion on demand by region for whites and blacks, and how much it varies within races and between regions: