Comment by jameshart

Overlapping bell curves are ripe for misinterpretation.

Look at the male/female height graphs on https://www.usablestats.com/lessons/normal for example (among the first examples that google came up with).

The thing that stands out is the difference between the bell curves - the area under the male height curve that is not under the female one. (Indeed, on this page, the way they drew their histogram version of the curve they explicitly drew attention to this area)

But this area isn’t representative of a meaningful population.

It’s just the sum of the excess number of men of a given height over and above the number of women of the same height.

Crucially, the vast majority of men accounted for within that population are still shorter than some women.

Unless you are, according to these numbers, over 77” tall - ie, over 6’5” - then there exist women who are taller than you.

Admittedly the population of people taller than you certainly skews heavily male - but for any randomly selected group of men, in most cases it is possible to find a group of just as many women who are all taller.

I personally find that the overlapping bell curve illustration obscures that understanding, making it emphasize more that a small number of below-average men are still taller than some women, and completely hiding the tail of outlier men on the left who are shorter than the vast majority of women…

Stacked histograms are a better way to visualize this kind of faceted distribution - but even that has issues.