Sunday, June 25, 2017

Environment and Intelligence

This NY Times article about identifying a very few (52) genes that are associated with intellegence is more interesting for what it says about environmental effects. Paragraph 2 "Just as important, intelligence is profoundly shaped by the environment."  Rather a naked assertion, there.  Paragraph 14, lead can harm intelligence, and iodine is necessary for development.  That's not usually what people are thinking of when they talk about "environment." On the lips of social scientists, environment usually means good schools, books in the home, a culture that encourages learning, and not being subjected to prejudice.  Not really the same thing.  Paragraph 33 tells us that nearsightedness, which is strongly influenced by genetics, can be fixed by changing the environment - with eyeglasses.  Well, fine.  What's the eyeglasses equivalent for intelligence that we're working on at present? It looks to me that we are going in a different direction, trying to claim (by analogy) that nearsightedness doesn't exist or is just diferently-optic, or that farsightedness is also a problem so don't get snooty, Paragraph 35 reminds us of the lead again.

Pretty thin gruel.  After genetics, the second most important factor seems to be randomness, which is uncomfortably large. Environment isn't showing up very solidly.

Which is not to say that it won't.  Yet if they had something, you can be sure it would be trumpeted. Something from the nurture side that we haven't thought to measure, or haven't been able to measure well, may still show up an be very important, and that would be grand because it would be a great boon to mankind and save us an enormous amount of money. We could just do that.  Equally useful would be clearly identifying anything that helps compensate that is also amenable to environmental influence, like determination, focus, or fortitude. (And I think there will be some, though not by quite the roads we travel now.)


Sam L. said...

Another example of why I find the NYT useless.

Laura said...

Oh, where to start? How about, if there are really 55 genes which increase IQ by half a point each, and one ethnic group has as many as half of them in most of their people, then that group will be 1.5 standard deviations above the rest of the population (*cough* Ashkenazi Jews *cough* ) and will dominate the intellectual life of society.

Environment: yes, there's still a lot to be learned about environment. When I was a kid, my mother worked as a pediatric nurse, and they routinely told parents that concussions were no big deal-- just a "brain bruise", into the early 2000s. Now, with more study, we realize that's completely wrong! Even one concussion has a measurable effect, especially if the person doesn't rest afterward, and repeated bumps that individually don't cause a concussion (think: heading the ball in soccer) can also cause a measurable drop in IQ. Epidemiology has a very hard time catching one-and-done kinds of environmental effects like this. Other possibilities: chemical pollutants, infections (like enteroviruses), unlucky combinations of events (you got virus X just at the time you were recovering from a mild concussion), etc.

Compounding the problem is what I call the "IQ floor": there's a minimum practical IQ level for any given task/skill. That is, if you graph the amount of time/effort/practice any task takes, as you move from higher to lower IQ, you'd see the line gently getting higher, then hitting a "knee" where quite suddenly it starts taking MUCH more to do it, and very quickly becomes effectively impossible.

An example: if you have an IQ=100, you probably don't even recognize getting money from the ATM as an intellectual task, it's so easy for you. But somebody with IQ=85 is "that guy" in line in front of you, taking forever to figure out what to do. Unknown to you, he probably only goes to one ATM, since the others give him confusing screens that frustrate him a lot. At IQ=75, somebody has to intensively train the person how to use the ATM, with LOTS of repetition and coaching; even then, he'll forget if he doesn't use it often. At IQ=70, it's effectively impossible to use an ATM. Somebody else has to get the money out for him. I could tell you a similar story about, say, the various math classes that people encounter: fractions, algebra, calculus, differential equations, etc., or really anything. At some point, you Just. Aren't. Able. To. Do. It.-- no matter how much willpower you have.

The trouble is, our economy is moving that "floor" up for the good jobs. There used to be real work for somebody digging ditches (IQ=70); but now, one guy with a backhoe (IQ=85+) will dig all the ditches. IQ=85 is a functional lower limit for semi-skilled trades these days (which means that 15%+ of the population, can't even do that!) And that's IF you have patient trainers and time, which few businesses have. So, a kid who could have been IQ=87 and could have been the backhoe operator, but "somehow" gets bumped down to IQ=83 (fell off his bike, got meningitis, exposed to lead, whatever)-- now there's nothing productive for him to do, even if he's willing to work really hard. (You can't let stupid people work a backhoe, because they break things and hurt people, because they forget rules, get confused, do things out of sequence, etc.-- even if they are trying really hard.) That's where we should be focusing our attention in education and public health-- making sure that nobody drops below some of these critical floors, if there's anything we can do about it.

I would put some of these floors at:
IQ=85: semi-skilled trades
IQ=95: limited skilled trades
IQ=110: Knowledge workers (coders, technicians, etc.)
IQ=120: Professionals (doctors, lawyers, engineers, etc.)

Assistant Village Idiot said...

@ Laura - I agree entirely about the knee and then the floor. If you look at the floors for enlisted men in the armed services there are only minor differences, but those cutoffs mean a lot. To oversimplify, there are some few jobs you can do in the army with IQ 90, but the USMC can only fit you in down to 92, with the Air Force having the highest cutoff at 95. That range is the "knee" you refer to, where people above 95 can be trained to a number of slots, but below 90 it's hard to find a use for you. (Various jobs within the Army or the Navy require much more than that, obviously. I suspect the Special Forces cutoffs are similar in all branches.)

I will only note that the 55 genes identified don't come near a half a point each, as far as I can understand.

Texan99 said...

It's pretty clear that environment and education can have a huge effect on your education and the rigor of your thought, but I think I'm with you on the slight degree to which it alters your basic horsepower.

Assistant Village Idiot said...

Environment can certainly influence where you put your energy. It does matter whether you study theology, chemistry, baseball statistics, or interpretive dance. I don't know if it affects rigor so much as exposes some to rigor who find they can do that and capitalise on it.