[cm127]

But that's the point... It's a continuous distribution meaning you probably fluctuate between introvert and extravert very smoothly with most of the population within the standard deviation. There will probably always be people that stay at the tail ends, but it's not average.

[GregorStocks]

The shape of the distribution affects the value of the introvert/extrovert distinction pretty strongly, though. If it's strongly bimodal (so a random extrovert is very different from a random introvert), then it says a lot, while if it's unimodal with a small variance (so a random extrovert is only a little more extroverted than a random introvert) it doesn't say much.