Kurtosis
leptplat.gif

Tail weight
If Average z score to the 4th power is
0 = mesokurtic
> 0 = leptokurtic
< 0 = platykurtic 2 3

If there are more people at the extremes of the normal curve, it is heavy tailed, positive kurtosis, leptokurtic.

Leptokurtic has heavier tails.
Platykurtic has lighter tails.