Actually, the upper-half of the IQ distribution is log-normal when ratio IQs are measured. Adult deviation IQs are percentile rankings coerced into a Gaussian d

Actually, the upper-half of the IQ distribution is log-normal when ratio IQs are measured. Adult deviation IQs are percentile rankings coerced into a Gaussian distribution (which is why measuring adult IQs above 145 is hard: small samples). This suggests that the "true" IQ is the log-normal distribution, which has support only on (0, infinity).