Active discussions

Please or to access all these features

Talk
Feminism: Sex and gender discussions

Feminism: chat

Original poster

Human Height is not Bimodal

91 replies

atoo · 17/05/2025 21:44

This is a bit of a niche topic I know, but I thought it might be interesting to at least some people.

If there's a scalar characteristic which has a different mean in men and in women, then the distribution for the whole adult population will be Bimodal if the difference in the means is large compared to the variation within each sex.

This is the case for example in gamete size or testosterone levels. But it is not the case for height - the difference between the average man and average woman is less that the difference within each sex. So human height is not in fact a bimodal distribution. It's just a bit flatter than a bell curve (image attached).

Much more detail in this paper: https://faculty.washington.edu/tamre/IsHumanHeightBimodal.pdf,.including why people often find bimodality in practice - e.g. small sample sizes, and men lying about their height.

Human Height is not Bimodal
OP posts:
Thread gallery
8
JellySaurus · 17/05/2025 23:30

So the pink lines and blue lines are more close to each other than more separate?

Human Height is not Bimodal
WallaceinAnderland · 17/05/2025 23:25

This is not new information.

GarlicPile · 17/05/2025 23:23

I knew someone had done a chart of this that I liked!

Number of people is on the left vertical axis (Y axis).

Summary:

  1. The tallest quarter of women are as tall as the shortest quarter of men.
  2. The tallest tenth of men are as tall as the shortest tenth of NBA players.
  3. The tallest one-hundredth of women are as tall as the shortest hundredth of NBA players.
Notes:
  • "Quarter", "tenth" and "hundredth" are approximations;
  • Most NBA players are men, this chart hasn't assumed they're a third sex
  • ... but maybe OP would like to explore that point 😏
Human Height is not Bimodal
Abhannmor · 17/05/2025 23:12

StripeySuperNova · 17/05/2025 22:57

Yeah, I'm wondering if we're supposed to go, 'oh, in that case it's obviously fine for men to use women's spaces.'

Ah.....now I get it. Or do I? Maybe I'm paranoid.

BernardBlacksMolluscs · 17/05/2025 23:06

A man told me he was bleeding from his genitals recently. I told him to get to his GP stat but maybe I should just have given him a tampon? Should I have measured him first? Gosh it’s so hard to tell what the right thing to do is in these circumstances

andtheworldrollson · 17/05/2025 23:04

I did introductory stats and make female height distributions never came up

the most normal thing to do would be to plot the two groups in different colours and see the difference in the mean and then run proper tests to see if the difference would be statistically significant

Circumferences · 17/05/2025 23:02

gasp some women are taller than some men

<Needs a lie down>

drspouse · 17/05/2025 22:59

(But sex isn't one distribution with two peaks.)

drspouse · 17/05/2025 22:58

If it was a bimodal distribution the averages for men and women would be further apart and men-who-are-shorter-than-average would not overlap much with women-who-are-taller-than-average.

StripeySuperNova · 17/05/2025 22:57

Yeah, I'm wondering if we're supposed to go, 'oh, in that case it's obviously fine for men to use women's spaces.'

Circumferences · 17/05/2025 22:54

What's the point in this post?

The average man is taller than the average woman.

I don't get it.

MarieDeGournay · 17/05/2025 22:49

JellySaurus · 17/05/2025 22:41

Translation, please.

I think they mean that there's as much difference in height within the group 'women' and 'men' as there is between women and men.
I think that's the long and the short of itGrin

JellySaurus · 17/05/2025 22:41

Translation, please.

Thelnebriati · 17/05/2025 22:31

''the difference between the average man and average woman is less that the difference within each sex.''

But thats just logical, isn't it? Given that people can range in height from 4 to 7 feet?

Original poster
atoo · 17/05/2025 21:54

Yes, it's very often used as an example of a bimodal distribution. There are many papers, textbooks, exam questions, and internet discussions that assume that it is bimodal - some citied in the paper I linked to.

From the intro to the paper: "The combined distribution of heights of men and women has
become the canonical illustration of bimodality when teaching introductory statistics."

OP posts:
alsoFanOfNaomi · 17/05/2025 21:47

Did anybody say it was? (Genuine question.) It would never have occurred to me to think it was; my subjective impression is that almost everything that differs between the sexes doesn't differ sharply enough to give a bimodal distribution.

Swipe left for the next trending thread