IQ Score Distribution


The theoretical distribution is like this (your post). But the true distribution is “a little” different, with little impact in the range -2.5σ to +2.5σ, but with a huge impact for scores well above +3σ. Please see the image below with a reasonably accurate model for the true distribution of scores (μ=100, σ=16, but not exact normal distribution. It is similar to Weibull distribution, but not an exact Weibull also).


Another interesting graph I’ve seen represents IQ capability in the bell curve.

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