Chisala has his 3rd installment up: http://www.unz.com/article/closing-the-black-white-iq-gap-debate-part-3/ One idea I had while reading it was that tail effects interact with population ethnic/racial heterogeneity. To show this, I did a simulation experiment. Population 1 is a regular population with a mean of 0 and sd of 1. Population 2 is a composite population of three sub-populations: one with a mean of 0 (80%; "normals") one with mean of -1 (10%; "dullards") and one with a mean of 1 (10%; "brights"). Population 3 is a normal population but with a slightly increased sd so that it is equal to the sd of population 2.

## Ethnic heterogeneity and tail effects

## Ethnic heterogeneity and tail effects

## Ethnic heterogeneity and tail effects

Chisala has his 3rd installment up: http://www.unz.com/article/closing-the-black-white-iq-gap-debate-part-3/ One idea I had while reading it was that tail effects interact with population ethnic/racial heterogeneity. To show this, I did a simulation experiment. Population 1 is a regular population with a mean of 0 and sd of 1. Population 2 is a composite population of three sub-populations: one with a mean of 0 (80%; "normals") one with mean of -1 (10%; "dullards") and one with a mean of 1 (10%; "brights"). Population 3 is a normal population but with a slightly increased sd so that it is equal to the sd of population 2.