05 October 2021

Height Gains In Korea

According to a 2014 survey, Korean men have grown about 15 cm (5.9 in) and Korean women have grown about 20 cm (7.8 in) over the past 100 years. . . . In fact, it is said that Koreans have grown the most in the world over the past 100 years.

From here

All other things being equal, height is primarily genetic. But all other things are not equal.

4 comments:

Guy said...

Hi Andrew, Super busy right now with start of federal fiscal year stuff so I'll ask you. Did you find a graph of adult Korean height vs. time? Naively I would expect it to plateau out at the average for that that geographic area. Of course is possible that the Koreans have drifted or selected to greater height than Manchurians or Japanese. And that should show up in a GWAS.
Cheers,
Guy

Dave Barnes said...

You mean SOUTH Koreans.

Guy said...

And... having spent a long weekend in Seoul at the downtown Hilton, I can verify that there are lots of young Koreans that look like they came out of the pages of Cosmo.

andrew said...

@DaveBarnes

I mean people who live in South Korea and Korean expats who migrated during or after the Korean War.

Quite a few people who migrated from North Korea during the war, or who are their children still identify as North Korean, so who is a South Korean is a somewhat problematic concept.

@Guy

Don't remind me about the damn fiscal year! It is breathing down my neck every day at this point.

I did not find a graph, but I know (from reasonable samples of friends, extended family, and popular culture sources) that it is predominantly post-Korean War generations (at a low point for people who in the U.S. would be Baby Boomer age and rising from there), and that it is pretty much a straight line increase from then to the present with time.

"Naively I would expect it to plateau out at the average for that that geographic area. Of course is possible that the Koreans have drifted or selected to greater height than Manchurians or Japanese. And that should show up in a GWAS."

I haven't seen any GWAS for height in East Asians.

There is a parallel trend, although a bit earlier and not quite as strong in Japan. The parallel trend in mainland China is significantly later (maybe starting in the 1980s). I don't have any evidence based intuition with respect to Taiwan, or with respect to the expat Chinese communities around the world.

East Asia-wide, I think that the current generation reaching adult height is probably the first to not suffer significant environmental deficits in modern times. But even now there are still significant regional pockets (like rural China, North Korea, and rural horticulture based farming areas in Southeast Asia) where environmentally induced height deficits remain significant.

You really need about 55-60 continuous years without environmental deficits in a region for your people to get to full genetic potential due to epigenetic effects. One reason Scandinavians were on the tall side sooner is that they were spared the worst deprivations of WWII that has lasting epigenetic effects.

If you did a GWAS, I suspect that the Japanese would have an average genetic height potential a bit less than Koreans and Manchurians due to Jomon admixture and due to drift driven by evolutionary adaption associated with sustained regular periods of food scarcity that is reflected in the Japanese diet (with its emphasis on small portions and diverse foods that even other East Asian coastal cultures have not exploited to the same degree due to lack of necessity).

Koreans are a blend of Manchurian and Han Chinese for the most part (with a North to South cline not fully reflected in available published and commercial data). But I couldn't tell you which of these historic ancestral populations were historically taller with great confidence, although I would suspect Manchurians were probably historically taller on average than the typical Han Chinese person. This intuition is due to lower population density, more herding, because they don't have island dwarfism or a milder peninsular version of that, and because they aren't so far north that Arctic/subArctic downward pressures apply. But, it might not be a statistically significant difference after centuries of moderate admixture and fairly random drift.

"having spent a long weekend in Seoul at the downtown Hilton, I can verify that there are lots of young Koreans that look like they came out of the pages of Cosmo."

News I can use.