> but there seems to be no upper definite upper limit to human intelligence I assure you this does not seem to be the case. There is an observed, and inexact,

> but there seems to be no upper definite upper limit to human intelligence I assure you this does not seem to be the case. There is an observed, and inexact, upper limit on human intelligence, just as there is with human height, and for broadly similar reasons: gravity, in the case of height, and for intelligence some much more hand-wavey limit to the amount of neurons and dendritic links a human body can construct inside a skull which has to fit through hips which are capable of bipedal motion. (Some of you are curious, and yes, there is a real correlation between skull volume and measured intelligence, but let's not bust out the calipers because it's a bad proxy for something we can measure more accurately with tests). Hence the IQ curve is, in fact, Gaussian, just as human height is, despite the fact that you can't be shorter than a mushroom, and the Empire State Building is an existence proof of very tall things.