- "United States or American” and “Unclassified or not reported” as US Census “nation of origin” categories are pretty much the same category. People who don’t classify themselves could choose either of these as their “nation of origin”. This may mean we’re looking at a proxy for southern blacks so it isn’t suprising that this is the most negative ecological correlation with IQ.
- “Swedish" and “Finnish” are Nordic “nations of origin” so their position as the highest positive ecological correlation with IQ matches the known (although slight*) correlation between latitude and average intelligence for Europe (Source: Greek IQ by Dienekes Pontikos) and confirms my suspicion that a big reason the motion picture industry casts blond males in negative roles is a resource competition from Jews—specifically for high IQ niches.
- The negative association between alcohol binging and IQ is interesting but the explanations are not quite obvious. Are we dealing with fetal alcohol syndrome? Or is it the fact that among the highest ecological correlates of binge drinking is the presence of blacks in the State and blacks generally test at lower IQs? And could low-IQ account for binge drinking prevalence?
*I should caution that the European correlation is not statistically significant by itself (r=.15 df=19). Significance may be imputed, however, by looking at the US data, which does show this correlation at a highly significant level, and the fact that any correlation among nations may appear lower due to differences in measurement/sampling between institutions. The positive correlation with latitude may be due, as Dienekes points out regarding the higher variation in IQ with lower latitude, to a more heterogenous population present in more southerly climates.