It’s just a normal distribution calculation. (I don’t actually believe that intelligence is normally distributed, so I don’t believe the argument.)
If you don’t think intelligence is normally distributed, isn’t that a problem for how true his results are and why one might want third-parties’ opinion? And I’m not sure that affects his rank-ordering argument very much; that seems like it might be reasonably insensitive to the exact distribution one might choose.
If you don’t think intelligence is normally distributed, isn’t that a problem for how true his results are and why one might want third-parties’ opinion? And I’m not sure that affects his rank-ordering argument very much; that seems like it might be reasonably insensitive to the exact distribution one might choose.