by Tyler Cowen
on August 22, 2006 at 9:21 pm
On average, taller people earn more because they are smarter.
On average, taller people earn more because they are smarter.
Maybe it’s not greater self-esteem.
Why don’t they just look at adult IQ scores and height?
With all due respect, of course the general premise does not hold. The difference between “tall” and “short” children in the United States (at least among people who grow up to take the kind of jobs talked about in the NBER paper) is not the result of “chronic malnutrition.” Therefore, any conclusion based on studies from the developing world are irrelevant to understanding the connection between height and intelligence (if it exists) in the developed world.
I’m not an expert in this area but I believe that there is a gap in heights between rich and poor adult Americans of about 1 inch. This wouldn’t be interesting by itself except that the gap used to be much greater (in modern India, the correlation between socioeconomic status and height is glaringly obvious). So this suggests that nutrition for poor Americans has improved relative to rich Americans significantly but is still not the same. In developing countries, poor people still have a large nutritional deficit that causes stunting. There is also a fairly strong, though certainly not perfect, correlation between height and IQ in the U.S. Genetics could be at work here as IQ almost certainly has a genetic component and height likely does as well but a rise in average heights in a country tends to correlate with a rise in average IQ scores, suggesting that nutrition is the link between these two.
Another somewhat weaker piece of evidence for the link between height and childhood nutrition is that average heights are higher in northern Europe — the Netherlands holds the world record — than in the U.S. and it is also true that babies tend to be healthier in northern European countries than in the U.S.
Stunting due to poor health is very probably the reason for lower intelligence in the population of shorter people.
In a nutshell, smaller people contain healthy people who are genetically small, but also genetically tall people who have been stunted by stresses such as poorer nutrition (including nutrition in the womb) and serious childhood infections (which produce anorexia and weight loss). (A few tall people are unhelathy due to growth hormone excess, but this is very rare.)
This is likely why there is a strong social class gradient in height (higher classes being taller), and why increased height also correlates with better health. Indeed, this is probably why tallness is attractive. This attraction has probably evolved as a way of selecting mates of higher reproductive value (on average).
So, by being attracted to taller people, humans are also attracted to (on average) healthier people. Healthier people probably are less likely to be carrying deleterious genetic mutations, and are less likrly to have their reproductive and child-caring lifespans shortened: so they will survive long enough to have more children and raise them to maturity.
There are, of course, notable exceptions. I realize the quote says “on average”, but the overall, average intellectual and financial success of Ashkenazi Jews, many of whom have tended to be shorter than average, is remarkable. For more, see the comments at
William – malnutrition probably isn’t the only factor, but it could be a contributing one. Sorry if I seemed to overstate my case.
Bruce, that doesn’t work in this case. You can’t make a broad statement about the overall correlation of height and intelligence, and then say, “But that’s controlling for other factors that might make our conclusion false.” If — for the sake of argument — Ashkenazi Jews are both shorter, on average, than the rest of the population and smarter, on average, than the rest of the population, then that suggests that the superior smartness of tall people may, in fact, not be real. You can’t, in other words, control for height if height is one of the variables you’re trying to measure.
Bruce, if you’re arguing on the one hand that height is the product of good genes and good nutrition, and then you want to control for genetic/nutritional factors (that is, those that are specific to Ashkenazi Jews, assuming they exist), then you are, in fact, controlling for those things you’re supposedly trying to measure.
To put it differently, you’re saying that tall people are smarter because the same factors that determine height also determine intelligence. If we look at a particular group of people and find that they are both shorter than average and smarter than average, then that is an important piece of evidence against your thesis. And you can’t do away with the counterevidence by saying, “Well, let’s control for all the things that these short, smart people have in common and then see if the thesis still holds, because the thesis is a statement about humans in general, not a statemtn about humans within particular ethnic groups.
“So, you’re saying the humans are dumb, yet… tall. How is that even possible? How can anything tall be dumb?”
— Almighty Tallest Red (“Invader Zim”)
When I was young I was smart enough to know I had to grow tall to be successful, so I did.
I couldn’t read the paper, but I hope they controlled for age. I remember the first couple of sentences in my first statistics course: “what if we link bigger feet to higher reading ability in children…big footed children are smarter?…no, children with bigger feet tend to be older and have higher reading levels because they have learned how to read better since they’ve had more time on this planet.”
I’m sure they controlled for age, but it would be comical if they didn’t.
BUT – if you were to control for all relevant, height-infuencing factors, then _all_ men would be taller than _all_ women.
Not true. One of the relevant factors is sex, so if you control for all relevant factors you will also control for sex, and men would be the same height as women.
Bruce, William Goodwin is right.
PS: to the above – it strikes me, somewhat belatedly! that William Goodwin is probably interested mostly in the hypothesis that Ashkenazi Jews are more intelligent than other groups, and that (if true) this may be caused by whatever (gene?) it is that makes them shorter. An interesting idea in its own right – and of course quite different from my hypothesis about health – however it may explain the confusion…
Phenomena:Taller people earn More;Shorter people earn Less.
Reason:Taller people are smarter;Shorter people are stupid-er.
It might be statistically significant that taller people earn slightly higher slararies than shorter people do.
But there might be 100 other more general explanations:
1.Natural Endowment: taller people are more stronger, muscular,or more phsically enduring…this is important feature in primitive society.
2.Humanity Preference:from a sociaological view,there probably be a humanity preference toward human height(just like better looking).The ancient Greeks, beofre they started Olympics,appreciated height as a beauty feature. so Higher people earns a height bonus.
3.History Inheritance: taller people won wars in long time ago.they conquer other lands, colonize, and accumulated national wealth. they are better off, because they robbed the tribes or nations of shorter height. They simply inherit that health.UK is still heard around the world for two reasons:(1)English Language(Shakespeare),(2)Past Robbery, colonizing, invasion,etc.
Some people might want to run to the issue of race,which I hope they better not think that way…you know,they might think the native Indians were conquered by the taller, “smarter” WASP…so blaa… you will be sued!
this is an argument really irritating
Can someone tell me how many ashkenazi jews have been tested in each of the famous studies on this field?? http://statisticsoftheworld.page.tl/
I just read the article in New York magazine. The “undervalued cat” touched me. Last year I purchased some “feeder fish” for our pond and my first aquarium. i started thinking about the chain of events that would lead to “feeder fish” being widely available. The resources involved all along the line are quite staggering. The fish are big and healthy and smart. Great pets. All the colour, motion, intelligence, and amusement of these beings cost $1.98. They got a life and I discovered a whole new world.
“feeder fish” for the aquarium
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