>think "there's a few of those in every high school class" Rather a few of those in every high school. 2 standard deviations means 2.5% per side. This is one i

>think "there's a few of those in every high school class" Rather a few of those in every high school. 2 standard deviations means 2.5% per side. This is one in 40 people, so probably on average 2-3 people per year in an average high school. Of course, pre selection can lead to higher values, but having several children outside of 2std dev in a class won't be average in the vast majority of schools.