The Other Side Of The Normal Distribution

aka "Every minute? Really?"

2004-09-29 20:29:19

The other day my 9yo genius daughter asked me why so much of the advertising stuff she saw in magazines and so forth was so dumb, and it led into a discussion of IQ and the Normal Distribution. No, we didn't rehash the debate in Herrnstein's Bell Curve and all that racial jive, just simple stuff about where most people were located on the curve, and then where she was probably located, and how advertising was often targetted to the largest audience. So if the majority of people fall into the 85-115 IQ range, you'll get an awful lot of ads that appeal to persons with an IQ between 85 and 115. My daughter Panda is rather far outside of that range, so there are some things that (to her) just seem really really dumb.

An admittedly simplistic analysis1, but it got the point across, and now she knows a little bit about standard deviations and distributions and slopes, so maybe she'll have a bit easier time grasping the details when she encounters a real statistics class in college.

So the next day at lunch the guys and I were talking about Nigerian 419 email: "please help me move $400,000,000 out of my country" etc -- just how could anyone ever fall for such an obvious scam? It seems incredible, it seems beyond belief -- but it happens.

But it struck me: here we are, four guys who (not to brag) are all at least a full std deviation out on the high end, and it's obvious to us that this is a rip-off. But the Normal Distribution curve is symmetrical. And so it's entirely possible that somewhere else in the world, there are four guys eating lunch talking excitedly about how Col. Ibriham Mustapha (rtd) is going to make them rich, rich, rich!

1 And one you may not agree with, but it's my blog and I'll make whatever unsupported assertions I care to make, thank you :)