As soon as we accept reality for what it is, we can begin adapting our societies and policies to maximize opportunities for individuals with the knowledge that our talents and limitations vary quite drastically.
People have a natural attraction to those similar to them. In history, the over-emphasis of particular and possibly unimportant (who knows?) traits has often been the cause for wars, genocides and all sorts of other evils.
Further, I don't think that relative Human intelligence has all that much magnitude. That is - a 'really intelligent' Human is not all that different from a 'non-intelligent' one, taken in the context of other species. And, those non-intelligent ones may have particularly interesting genetics that make them important to the species, in other ways.
Humans have done pretty well as a species with lots of diversity. Why ruin a good thing? And, do you really want Humanity to be comprised of near clones?
All to often, people start using it as justification for income disparity, wealth disparity, minority crime rates and sometimes differences in economic development between different countries. Racism and classism aren't too far behind.
I'm reminded that it is no more noble to fool a person out of his money by outwitting him, than it is to bully him out of his money with superior strength. Being smarter isn't necessarily a moral justification for greater rewards.
Similarly, we rely on the economic system using prices as an information signalling mechanism; more valuable labour is priced up, and thus supply should follow. But if the valued labour is intelligent labour, and its supply is not easily increased, then there is less of a moral case for paying its suppliers more, for that attribute alone.
I think the difference between these 2 opinions is their definition of intelligence.
I don't think I've heard anyone serious say that there was no heredity of intelligence. Could you be more specific about who says what? Perhaps you are writing quickly, but these are imaginary statements from imaginary people.
Because athletic ability is more recreational - you can say different people are good at sports, music, art, etc... there are nice alternatives. But it's not PC to imply anyone is inherently stupid. I phrase it that way because saying "inherently smarter" is OK on the surface, but the corollary is that someone else is inherently less smart. Being "PC" is all about not offending anyone.
Outside of professional athletes, being good at soccer is not much more important than having blue eyes.
Intelligence, on the other hand, is an underpinning of modern life.
The only reason we acknowledge the heritability of wealth, another underpinning, is because it is by far too obvious to deny.
(Quite the reversal from the origin of the species!)
Secondly, I gladly accept your reductio of a "general factor of fitness". If you restrict yourself to the range of world-class athletes, I grant that performance in archery will correlate negatively with performance in sprinting. This is just Berkson's paradox, or the "restriction of range" phenomenon. If you consider the entire population, however, I would be very surprised if a "general factor of fitness" didn't fall right out of a battery of athletic tests. In general, people who are faster than average will also be stronger than average and probably more dextrous too, and it makes sense to call that factor "physical fitness".
Intelligence simply doesn't work the same way, learning to draw well won't make you worse at computer programming for example.
1. Pick an arbitrary athletic contest: 100m dash, bench press, obstacle course, marathon, whatever.
2. You pick a member of the population at random.
3. I pick a member of the German national football team at random.
4. If Joe Schmoe wins, I pay you a dollar. If Dieter Schmieter wins, you pay me a dollar.
5. Repeat until convinced.
Who do you think will win more money in the long run? Will the Germans tend to win because of their high general fitness, or will it be a toss-up because the Germans merely have "high soccer fitness" which does not help (or perhaps even disadvantages) them at non-soccer tasks?
That is what I mean when I speak of a "general factor of fitness". Over the whole range of population, people who do better at one athletic task will tend to do better at any other. If you take a sample from the population, measure their performances on whatever athletic tasks you choose, and drop the results into PCA, you will find one factor which is positively correlated with every test and explains, I'm guessing, at least 3/4 of the variance. What happens at the extreme tails is already acknowledged, and does not bear on this general point.
I tried to find data for non-elite-athletes taking something like the NFL combine and couldn't find anything, but there, at least, is a testable prediction for you.
My only point about a "general factor of fitness" was that I am unfazed by the comparison to IQ, because physical fitness is a perfectly reasonable concept that captures something real in the world. So too IQ. If you think the analogy is inapt, remember who brought it up :)
Amongst the general untrained population you will see very large variance between performance on different fitness tests. Lots of broadly built overweight people who are very strong despite never having done any weight training but can't walk up a flight of stairs without breaking a sweat and skinny people who can run well without much training but barely lift anything. So I would doubt that there would be a strong general factor for physical tasks.
Intelligence, I think, can broadly be defined as "the ability to score well on intelligence tests." The most common is supposedly correlated with freshman college survival. History is full of people who were considered "dull" as students but later shook the world in a way that means they had significant intellect.
It wouldn't be a problem except we sort people into piles and this is yet another sorting mechanism.
I think this question is more fuzzy at the 100-year time scale than the 200, 500, or 1000-year scale. It seems fairly uncontroversial that "merit" (whether by pure intelligence or some other metric for skill) had little to do with your station in life in 1514.
> The value of specific cognitive skills varies over time.
True. We should be careful not to anachronistically apply meritocratic assumptions about intelligence to other eras where raw intelligence and mental flexibility was less important than domain knowledge and practiced skill. But can we safely say that the Information Age has put a premium on the skills of those with high intelligence, and the benefits accruing to those workers over the last 50-60 years has skewed the mating priorities of many?
> There is far more to capability than intelligence. For example, there are very smart people who, due to lack of emotional or interpersonal skills, don't produce much.
Also true. Murray is careful to note that when we speak about meritocracy or the hereditary impact of intelligence, we can really only generalize about groups -- it can be wildly inaccurate for individuals. Can we safely say that the Harvard Class of 2014 as a group will have greater economic value over the course of their lives than the Anytown Junior College Class of 2014?
An interesting hypothesis.
1) Are the U.S. economy and society more meritocratic than they were 100 years ago? I've seen research saying social mobility has decreased recently (it didn't say about over 100 years) and is lower than in Europe, for example. Also, at least some research says that access to higher education depends significantly on the wealth of your parents; elite universities (and others) have problems attracting and graduating poor, smart students.
2) The value of specific cognitive skills varies over time. If 100 years ago, you had great ability to translate problems into efficient data structures and logic, I'm not sure how much economic value you would have. 50 years from now, I'm not sure how many humans will be writing code.
3) There is far more to capability than intelligence. For example, there are very smart people who, due to lack of emotional or interpersonal skills, don't produce much.
Regardless, while the absolute cost of raising children may be higher for high-income families, the share of their total income that represents is much lower. Someone earning minimum wage will struggle to support even one child's basic food, clothing, and shelter; their counterpart making $1M a year could easily afford private school, childcare, and the best possible opportunities for a family of 3-4 children.
Survival rate is unlikely to be highly correlated with income in a first world country because even the poor have relatively good healthcare. The group most likely to have children are those earning $10,000 per year or less, probably because at that income level the state will pay most of the costs associated with child rearing. In fact in some cases having children might make a person better off financially due to higher priority for welfare or public housing etc.
This follows from the two conditions:
1) intelligence is at least somewhat heritable (empirically true, according to the article)
2) intelligence is positively correlated with reproductive success (plausible give humans seem to have been selected for it)
The conclusion follows from the way world population has exploded in the past 250 years, increasing roughly ten-fold in twenty or twenty-five generations. That increase equates to "zero selective pressure": basically anybody could breed successfully, and they did (including my ancestors, some of whom occupied the more stagnant and brackish depths of the gene pool...)
So up until 1750 or so intelligence was being selected for, generation after generation. After that time, there was no pressure and the many small effects that this article documents as underlying the heritability of intelligence (with no single gene showing as much as a 1% effect on the overall outcome) would happily carry us all on a random walk across the landscape, creating engineers in some parts and political partisans in others.
This realization makes particularly funny the various organizations that have at times promoted Nobelists etc as pinnacles of intelligence (William Shockly, inventor of the transistor, was heavily involved in this kind of thing). Nobelists are certainly bright, but it seems more likely you'd find the most intelligent people amongst still-extant stone age tribes, whose pre-industrial life-style would still subject them to selective pressures long released in the more-developed world.
This conclusion is only justifiable if (1) the population of "stone age tribes" and the part of the world where those selective pressures have been released (because people are indivisible units beyond a certain point), and (2) if intelligence was fully determined by genetics rather than merely having some heritable component.
If there are important environmental factors in intelligence to which modern technology can positively contributed, and there are a lot more people living with modern technology, then its quite possible that the mean, median, and max realized intelligence would be higher in the modern part of the world than in "stone age tribes", even if the latter have more genetic benefit from pro-intelligence selective pressure and thus a higher mean/median genetic intelligence capacity.
People are economically unproductive because the economy slowly gets more and more hostile to more and more people. Tyler Cowan and others call this problem "Zero Marginal Product Workers".
Luckily we don't have to go there. Technology is going to be the great equalizer, and might end up offering you off-the-shelf intelligence upgrade (I'm talking about a time-frame of next 30-80 years).
Dr. Kling is using the book as a template/metaphor more than as a specific proscriptive. But I've seen this myself in the wind as various crises have held forth since 1973 ( when I was first old enough to ask questions about what was going on ).
Also that article reeks of alarmism.
Even all the breeding done with dogs has not resulted in speciation.
The time scales are vast and the degree of separation that a barrier such as 'intelligence' (for whatever definition you wish to employ) will provide will be insufficient to cause this to happen.
No Elois and Morlocks in our future through that avenue.
Think about it: if geographic separation and very long spans of time have not been enough then why would a mere trait be enough, we have plenty of examples of the former.
That said, your point about the time scales is definitely on mark. It would take a long time and likely far more significant isolation than present (don't have numbers). Genetic engineering could speed that up substantially.
Of course social factors would likely prohibit any talk about separate species. From a pure biologist perspective there are many different animal species fully capable of reproducing but are speciated because their natural breeding behavior (or location) doesn't support interbreeding. Using the same measure/definition, one could objectively argue that uncontacted tribes and isolated peoples are a different 'species'.
I personally think scientists need to agree on some fundamental genetic/epigenetic (maybe even microbiomic) markers of speciation and move away from more subjective definitions. Reproductive potential makes sense when looking at speciation likelihood, but I am not sure it makes sense as a definition of different species.
So if two specimen are capable of breeding and the resulting offspring is not sterile they are considered to be of the same species.
Being from an un-contacted tribe has nothing whatsoever to do with speciation.
Being genetically capable of interbreeding makes sense as a definition of speciation, but that is not how species are currently identified. Natural range, aesthetics, and more than that, whether or not they DO interbreed in the wild (vs physically/genetically capable) play a more significant role in determining species.
There are many 'hybrid' species in nature, which is what I feel warrants some revision, perhaps using genetic data to restructure many classifications as subspecies rather than independent species.
edit: Sorry, I think I may have misinterpreted what you said to some extent and think we generally agree. I will maintain that according to the classification methods described, people such as the Sentinelese, may well be considered a separate species to an unbiased observer using the same guidelines we apply to other animals due to slightly different physical characteristics and social/geographical reproductive isolation prevents the possibility of breeding with anyone outside of their group.
It isn't, and cannot be. The relation A interbreeds with B is not transitive.
Larus Gulls originated in Finland and spread west, evolving as they moved. Eventually some of them reached England. The Finnish ones breed with the Russian ones, Russian with Canadian, Canadian with English, but the English don't breed with the Finnish.
If a 3 million year old ancestor would suddenly pop out of nowhere into our midst chances are that we're far enough removed for interbreeding to be impossible and yet, we were able to breed at every intermediary stage just fine.
But for all normal everyday intents and purposes that definition holds up just fine. It's when you start to zoom in on what a species really is that it becomes more nebulous until you realize that all there is is individuals and their breeding capabilities.
Species are a phenomenon that is observed rather than one that actually exists.
It would take intentional segregation to cut off all gene flow between the upper and lower halves of the intelligence Bell curve, thus allowing other differences to pile up between the populations, to cause speciation. And as noted elsethread, that's called eugenics and generally frowned upon in polite society.
What makes you think that? You could say the same thing about seed size in plants, but comparing modern corn kernels to wild type seeds provides a clear counterexample.
You should look at the type of stuff they've done in plants and animals. Here's a paper on the selective breeding of fruit flies for flight speed. The results are astounding:
"The mean apparent flying speed of both lines increased from approximately 2 to 170 cm/sec and continued to respond at diminishing rates, without reaching a plateau, for 100 generations. Competitive fitness tests in generations 50 and 85 showed minimal or no fitness loss in selected lines compared to controls."
They mention assortative mating is greater for intelligence compared to physical aspects like height and weight, but 'prettiness' is a more subjective harder to quantify measure that I would guess plays a larger role in mate selection than just height and weight. This is ignoring the fact that height and weight are probably opposite anyway (women wanting taller men, men wanting shorter women) - so there are some issues there too.
Let me know if I'm mistaken...honestly I've only read part of the article and I only have a lay understanding of this stuff.
2. Expert review = exactly what it sounds like (as opposed to original research)
3. Something in-between
That is a valuable piece of information for us lay people. Do non-geneticists studying the issue generally agree with him?
> 3. Something in-between
Much appreciated (all of your answers). If someone has knowledge of where this falls on the continuum of #3, it would help those of us outside the field understand how much credibility we should give to this article.
If these findings are surprising to you, it is because there is probably no greater gap between lay and expert opinion than on the subject of intelligence. The psychological study of intelligence has a poor reputation among the lay public primarily due to the perception that it might support unsavory political conclusions. Hence, psychometric research must be intrinsically flawed crackpottery. In truth, the correlations between IQ and various life outcomes exceed practically any other effect observed in social science. Further, we have as much reason as we ever could have in social science--from a variety of sources all pointing in the same direction--to suspect that the causal arrow points from intelligence to good outcomes.
I encourage you to look into the issue for yourself, but my synopsis is that the picture one gets from the literature is unrecognizably different from the picture one gets from non-specialist media.
> If these findings are surprising to you
Not knowing much about the field, I didn't have many expectations.
[Edit: I don't know about the US but here in the UK it is fairly common to define "merit" in ways that don't actually seem to include "performance" - though I think this is a far bigger problem in the public sector than the private].
Q: What are intelligence tests?
A: Things that measure intelligence.
This being the internet, the serious answer is a mouseclick away: http://en.wikipedia.org/wiki/G_factor_%28psychometrics%29
What I am getting at in a roundabout way is that I cannot find any credible definition of intelligence that is not dependent on the these tests. If intelligence were able to measured some other way that corroborated these tests, then I will be more likely to believe them.
A crucial detail (Deary and Plomin would both agree about this, but it hasn't come up in the discussion here yet) is that heritablity has NOTHING to do with modifiability. It is quite possible in principle that a novel environmental intervention might be discovered that could boost most people's intelligence. It is even possible that the most effective intervention might have a gene-environment (G × E) interaction such that the intervention would most help people with lowest IQ, and least help people who already have high IQs. No such intervention that human beings can direct purposefully has yet been found, but it is clear from the Flynn effect that something in the environment can have powerful effects in raising average IQ levels of whole countries, as has happened in the developed world throughout the last century (for as long as IQ tests have been around).
It is correct that people marry and have children on bases other than just shared level of intelligence. (But living in the same town, and completing higher education at similar ages, and pursuing compatible occupations for marriage, etc. is correlated with IQ.) It is still far too early to say how rapidly human populations might see noticeable effects from assortative mating by IQ. It is reasonably clear that often-feared dysenic trends probably are NOT happening--the lowest-IQ people in the world population don't reproduce at all, and high-IQ people actually have reasonable numbers of children to replicate their genes. In any event, the favorable environmental trends have SWAMPED whatever genetic trends are going on for IQ in the whole human population, and people are getting smarter all over the world, according to the research on the Flynn effect.
It is still a hard problem to identify anything at all meaningful and replicable about how gene differences influence IQ differences, even though it is now settled wisdom that they do. Human IQ, as the article says, is influenced by MANY genes, and many of those genes interact with one another in ways that are not understood at all yet.
The only thing missing is that the genome-wide polygenic score (GPS) for intelligence has yet to be discovered.
Unfortunately, even when something like this is possible, it would probably be made illegal even though it would surely be a positive thing for humanity.