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Recently I noted that the vast majority of Americans earn five figures a year (middle class) and by definition the average American has an IQ of about 100.  I also pointed to studies showing that the homeless earn three figures a year and have an average IQ of 84.  I used these two facts to hypothesize that for every ten fold jump in economic class, average IQ increases by 8 points.

Several skeptics warned that I could not infer a pattern from only two data points (the homeless and the middle class).  But I now have a third data point: Welfare recipients.  It’s common knowledge in psychometric circles that reading comprehension correlates very well with IQ and a literacy study found that about 2/3 to 3/4 of adult welfare recipients (about 71%) have what’s classified as Level 1 or Level 2 literacy.  By contrast, 1/2 of the general adult population are at these levels.  Since by definition, 1/2 of Americans have IQ’s below 100, it can be deduced that 71% of welfare recipients have IQ below 100.  In a normal distribution, the 71 percentile is 8 IQ points (0.53 sigma) above the mean, so if IQ 100 is the 71 percentile among welfare recipients, the average welfare recipient should have an IQ 8 points less.

In other words, American welfare recipients average IQ 92, which is exactly what my model predicted was the average IQ of four figure income earners.