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Comment by misja111 | Hacker News Reader

I've heard the explanation that the tallness of the Dutch is because they consume so many dairy products. It sounds quite plausible to me, because if you look at the other countries in the top of the list, many of them are countries which consume a lot of dairy products as well. It even could explain why the Maasai are so much taller than other Africans, because they drink a lot of cow milk too.

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I doubt it. I come from the South West of England (known for enormous consumption of dairy products) and people aren't tall. I'm just under 6ft and was tall there, whereas I'm short here in The Netherlands.

It's probably a combination of genetics, cycling everywhere and eating so many slices of brown bread and potatoes.

Basic statistics also plays a part: when comparing arbitrary groups you'll often see smaller groups as outliers. Both high and low. Dutch population isn't huge (16m) so that is also a contributing factor..

Good point about the outlier bias for small countries. It could explain why Estonia, Latvia and Iceland are in the top 10.

> often see smaller groups as outliers

Is there a name for that phenomenon? I saw a similar thing in some data that we were looking at recently, and it took a while to work out that the reason why one group's number was consistently a bit smaller than another group's number was that we were simply taking the max of a smaller group. it's obvious in retrospect, but can catch you out if you're not expecting it.

I'd like to have a name for it, a reference to send people to.

I think the terms you're looking for are local maxima and minima.

I have looked at the reference for this (1) and I don't think it captures the idea that statistically, small groups vary more.

1) https://en.wikipedia.org/wiki/Maxima_and_minima

Ah, I think I'm with you now. My stats is rusty, but I think what you're asking about is one of the fundamentals of variance.

I think this[1] Stats StackExchange answer frames it well.

[1]: http://stats.stackexchange.com/questions/129885/why-does-inc...

That is helpful, thanks. Especially this part:

> I believe that the Law of Large Numbers explains why the variance (standard error) goes down when the sample size increases. https://en.wikipedia.org/wiki/Law_of_large_numbers

So what I was looking at is the inverse of the law of large numbers.

Yeah, the Dutch may be more into carbohydrates than other countries.

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