Average IQ scores seem to have been falling and population ageing may be why
newscientist.com
newscientist.com
Alternative hypothesis. Presence of computers/phones reduces need for working memory, so it doesn't get exercised and leads to decline of it.
A typical example is GDP is going in country X, which means X is doing better!!!
Except mean salary is going down, which is a typical for a rich get richer, poor get poorer scenario.
Belief in the face of evidence to the contrary has been accomplishing great things all over the world lately.
(a) elevating a Hollywood comedy into some sort of social study / prophecy status is "smart",
(b) calling the majority of people on earth idiots (which the parent did) is also OK,
but that only "idiots" would call them out for doing so.
You become dumber as you get older (I unfortunately know this from personal experience), while the average intelligence of each generational cohort can also be changing through differential reproduction.
Especially given things like the Flynn effect.
But "intelligence" / "IQ tests" are tangled up with a lot of correlating factors and biases so it's hard to say what this means. For instance, simply being poor affects cognitive ability considerably -- https://www.princeton.edu/news/2013/08/29/poor-concentration...
We also know that low fertility is also associated with high education levels -- http://www.jstor.org/stable/2137845 -- and income -- https://papers.ssrn.com/sol3/papers.cfm?abstract_id=838227
I think one key here is, now that infant mortality / childhood diseases are much lower than it used to be, a much larger portion of families really want to use family planning methods to keep family sizes low, globally. This is not necessarily a bad thing. http://www.economist.com/node/14743589
So I would take a statement like "the stupids are outbreeding the smarts" as more that, for multiple reasons, access and knowledge of family planning is not as good for those with less education or income. So rather than making this a moan about dysgenics and Idiocracy, it seems a call to action to absolutely ensure these people at least have the access to the health care they need. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2835625/
Children are much more expensive to the highly educated, both directly through things like housing and education, and indirectly via opportunity costs. The more expensive you make something the less of it will be consumed unless it is a Veblen good.
IQ scores are relative to people the same age, so it wouldn’t matter.
It doesn’t because it’s a bell curve. You literally can’t figure out your score until you already know the distribution.
I think there would be significant noticeable losses in IQ due to social factors, too, and to a much greater extent than most people would appear to believe when they talk about the heredity of IQ but then think that means IQ determinism..
For example someone could test at 115 IQ, become homeless, then have something much closer to ~100. (Do not use "but someone that smart would never become..." as a cop-out..)
"Young people in England are the most illiterate in the developed world with many students graduating with only a basic grasp of English and maths, an in-depth analysis by the Organisation for Economic Co-operation and Development has found. The OECD report rated English teenagers aged 16 to 19 the worst of 23 developed nations in literacy and 22nd of 23 in numeracy.
In contrast, pensioners or those close to retirement were among the highest-ranked of their age group."
https://theeconomyofmeaning.com/2015/11/12/new-study-shows-r...
It's like https://xkcd.com/603/, except White Hat is is wrong on most accounts.
"You arguments are wrong because Flynn effect, and if this one is reversed then your arguments are wrong just because."
Everybody these days is a eugenicist in that they all support the idea of helping pregnant women give birth to health children by ensuring they are well nourished and given good medical support. The section of 20th C. eugenics that is controversial is the part that suggests that one section of society should have more or less children.
Here's a recent and fairly pro-eugenics survey of all the results they could find showing a reduction in IQ:
https://www.gwern.net/docs/iq/2016-dutton.pdf
And even they basically are only at the stage of saying "maybe there's a hidden trend, that's obscured by other trends moving in the opposite direction" (they think society becoming more abstract has caused a false rise in IQ, due to IQ tests measuring that socially taught facility with abstraction rather than raw intelligence, this may have disguised an actual drop in intelligence).
So maybe it does help to have a preconcieved cause to spot this hypothesised trend.
Regarding their hypothesis, it's kind of a philosophical question about whether you'd rather have a society full of uneducated bumpkins (not sure there is an english word for someone with raw intelligence but no education) with sharper reflex times or ability to discern colors, than a modern post-graduate who scores slightly worse on those tests but better on IQ. It's also somewhat unlikely that the former is going to be having less children than the latter, so they whole dysgenic thing seems to be on shakey ground.
Unless all the people I personally know are very unrepresentative of society in general I have a hard time believing that there is not a negative effect on IQ due to differential fertility.
Though, in my opinion, education quality has gone down.
In France, 2010ish?, in my last year of high school (in one of the best parisian high school) there was a boy who couldn't read aloud a text without stumbling. I don't know if this would have happened in the past. But back then only 20k students reached that stage and now it's 200k.
edit: stumbling/stuttering
In other words, he was 17 and couldn't read fluently. But he wasn't stupid. He was quite conscientious about his side business and bookkeeping.
ps: I stuttered when I was a child.
I've read and written in English everyday for 10 years. I just can't speak it. One day I realized most news article I read were only translations of other articles. So I decided to skip the middle man.
Is that your professional medical opinion?
What would you think if I told you I graduated in the 1990s and I felt the same way? Where would that put you?
>there was a boy who couldn't read aloud a text without stumbling.
There could be other reasons for that, like fear of public speaking.
He didn't fear much. He was a bully.
Let us assume the answer is no for the sake of argument. Does that necessarily mean the quality of education has dropped? Not necessarily. It could mean that 30 years ago this boy would have failed to graduate.
This doesn't mean that the education was any better then, only that the requirements for graduation are lower now. The top and average students today might be leaving with better knowledge and skills than 30 years ago even if the very bottom looks "worse" because fewer people are pushed out entirely. Perhaps the value of the diploma itself diminishes as a result of this, but that doesn't mean the actual education has diminished.
Of course it's also very likely that there have always been people graduating like this.
It would be like Ferrari finishing last in a 21st Century car race and concluding that cars are going slower that they used to.
It would be interesting if China, Japan, Korea aren’t affected while Western countries are.
Historically we had neither massive population aging nor Ponzi pension systems to worry about. Now we do.
Let me ask you how many of immigrants are grad students or prople with high tech jobs?
Is it one of the stupidest thing to say drop in IQ is connected to immigrants!
It is greatly disappointing to see this kind of nonsense in HN which is kind of home for many hackers and programmers. Hearing these kind of stupid ideas in C-Span? Who cares? But HN, that shows how low our societies has become.
Now let's say that you make it difficult (either deliberately or due to language barriers) for individuals in the left-most part of that graph to stay. What happens long term? I don't know.
Depends on the country of entry and the country of origin.
The majority of latin America immigrants in the US, or African immigrants in France for example will be nothing like "grad students" and "high tech jobs".
>Is it one of the stupidest thing to say drop in IQ is connected to immigrants!
It's actually a pretty decent explanation. If different countries have different average IQs (which we know to be correct) and if the mass immigration is not of the "grad student" type (which we also know to be correct), then it's a good explanation, assuming there's no other factor that we neglected to examine. Remains to be seen if this is indeed the case or if there's another cause (or perhaps multiple causes).
>It is greatly disappointing to see this kind of nonsense in HN which is kind of home for many hackers and programmers. Hearing these kind of stupid ideas in C-Span? Who cares? But HN, that shows how low our societies has become.
You are ranting. This is not a reasoned argument against the parent's argument. This is what's anti-hacker and anti-science.
FYI the parent comment was not reasoned argument either. The notion of relation between education and IQ is questionable.
>It's actually a pretty decent explanation.
No it is not at all. Since it requires rigorous calculation and estimation of how much immigrants have come, what is their average IQ, how much drop we see in population and so many questions.
This is what “pointing finger without any evidence” looks like. I don’t understand why you would consider your approach scientific when I am the one basically asking and questioning all the moving parts.
Questionable based on ethical considerations is not the same as non-rational.
It's a very logical thing to consider. A mechanism for example would be that people with higher IQ also tend to succeed in completing more higher education degrees. The inverse is also possible, and it's also a perfectly valid thing to suggest and study. In fact it's studied e.g. in this paper: http://www.pnas.org/content/109/2/425.full.pdf
>No it is not at all. Since it requires rigorous calculation and estimation of how much immigrants have come, what is their average IQ, how much drop we see in population and so many questions.
That's what's required to get a full result. It's not however required for merely putting forward the argument as a possible explanation, or for judging whether the argument is rational or not.
It seems that your concerns are more tied to a priori axioms and emotional resistance than actual methodological issues in the questions.
This is the difference between you and me. Before putting an argument forward I would evaluate it or at least calculate it a little bit!
>It seems that your concerns are more tied to a priori axioms and emotional resistance than actual methodological issues in the questions.
Why would you say that? The only thing i wanted was a little bit evidence and calculation! And it is funny in your nonsense world I am the emotional one here!
Did this difference emerge very recently?
Because for someone who claims that, it seems bizarre that you entered this thread by stating: "Let me ask you how many of immigrants are grad students or people with high tech jobs?"
How is that more "evaluated" or "at least calculated" that what the parent wrote? Where were the numbers that go with this?
You then went on to give non-arguments combined with non-facts: "Is it one of the stupidest thing to say drop in IQ is connected to immigrants!"
And on with the non-arguments + non-facts: "It is greatly disappointing to see this kind of nonsense in HN which is kind of home for many hackers and programmers. Hearing these kind of stupid ideas in C-Span? Who cares? But HN, that shows how low our societies has become."
or not? And asking question or pointing calculation flow in one argument has nothing to do with evaluating your idea before puting forward.
Seriously, Why do you keep repeating yourself!
I am curious as to the distribution of jobs amongst immigrants.
The portions are well discrete. IQ test has nothing to do with linguistics ability (at least we don’t know it) and most of IQ test don’t require you to read or write anything.
The most widely used IQ test has explicit verbal testing.
https://en.m.wikipedia.org/wiki/Wechsler_Adult_Intelligence_...
Verbal testing is different than spatial ability testing? Do you see the logic? Verbal testing is separate skills. And spatial skills are different too.
>The most
Completely false.
> Verbal testing is different than spatial ability testing? Do you see the logic? Verbal testing is separate skills. And spatial skills are different too.
Because I do have the answer. The article asserts that average IQ is falling. It does not indicate that only, e.g., spacial ability is falling. Given that verbal is a direct component in its own right (as well as a factor in other areas due to comprehension and communication), it is reasonable to state that verbal is likely a factor in the falling average IQ.
> Completely false.
It's not completely false. WAIS is extremely widely used. It's not simply the most frequently used IQ test[1]. It's one of the most frequently used clinical assessments in general.
You're just asserting things you want to be true. If you disagree that WAIS is the most common clinical IQ test, then provide some info on what you believe is more common. Otherwise your claims are clearly without merit.
[1] http://www.pearsonclinical.com/psychology/news/2008/wechsler...
You gave your answer here:
>You're just asserting things you want to be true.
Article states the IQ has been dropped. We don’t knew which part, we don’t know why, we don’t now how much.
You are just saying “immigrants have problem with language” -> “immigration causes this drop”. This is total nonsense. We don’t know. Maybe there is the change is related to influence of smartphone and etc. has you calculated how much immigrants we accepted? How much our IQ has been dropped? Does the math makes sense with these numbers or there should be other factors?
We don’t know. Do you understand what “we don’t know” means?
I think the best answer is what you gave to yourself.
>You're just asserting things you want to be true.
I never said anything like that. My comments have addressed nothing except your claim that linguistic skills are irrelevant in IQ tests, a claim which you've clearly based on nothing.
> This is total nonsense. We don’t know. Maybe there is...
No one said that this is the cause. Someone proposed it as a potential reason. Someone else proposed that if so, the language barrier might be the issue. These are just hypotheses. They might be right. They might be wrong. They might be contributing along with many factors. The fact that "we don't know" doesn't mean it's unreasonable to discuss, though.
> Do you understand what “we don’t know” means?
You should ease up on the condescension toward others. You're clearly not even reading comments at this point. You're just ranting and your arrogance is unwarranted. I don't know why you're so upset that someone would suggest that immigration might impact a nation's measured IQ, but if you can't engage civilly, maybe you shouldn't engage.
(By the way, it did not escape my attention that you again failed to provide any sources that back up your claims about IQ tests. You seem to demand a much higher standard of evidence from others than you demand of yourself.)
I asked for statistics and wanted a number. pointing ideas without any numbers is ridiculous. I am fascinated how much people can ignore what they don't like to see.
For one, they are all ancient civilizations -- most western countries aren't.
Second, they have different value systems (more collective than individualistic).
Third, they have different nutrition and culinary preferences.
Fourth, they have differences in lifestyles.
Fifth, they are more homogenous than a lot of western countries like the US, Britain and France, with much smaller (percentage wise) immigrant populations.
In most aspects, a place like Chicago and a place like Tokyo might as well be on different planets.
I've seen some things mentioned here that utterly baffle me, and confirm my bias that IQ is good for understanding but has little relation to wisdom or 'overstanding'.
I am very worried about what will happen if we start doing rash things like mass removal of autistic embryos from the gene pool. I've seen it suggested too often, compared to the amount of people I imagine are actually deeply informed enough about both to speak on such things. It's strange to me that such an idea is not automatically considered risky, or obviously married with unintended consequences.
On the surface of it, you might increase the median IQ by a few points. But you'd also miss out on the next Newton, Turing, Einstein, Kant, Cavendish, etc etc (I've plenty of other speculatives). There's no free lunch. Shaking the Tree of Life and hoping something tasty falls out sounds very unwise to me. As far as I'm concerned the major problem for humans is not their absolute IQ levels - it's arrogance relative to engineering capabilities.
Lastly: if we ever make it through climate change and out the other side with powerful AGI, I guess high IQ won't be as central compared to EQ or creativity, except as something that roughly correlates with both.
Edited for clarity.
But there is a much stronger way to believe IQ is not the same over time : intelligence is not normally distributed, at all. It really is meaningless to try to measure intelligence samples and call them independent and identically distributed random variables, whether the 'population' is an individual at one snapshot or over time, or an individual in a group (whether over time or not).
Intelligence is probably better measured by a power-law distribution than the normal distribution, whose key property is that it is the probability distribution that maximizes entropy/minimizes information. So maybe there would be a larger discrepancy (relative entropy aka Kullback-Leibler divergence) in measuring IQ as a normal distribution over time than expected (maybe that's the whole reason for the Flynn effect and the author writing this article..)
Could it be this:
http://www.advancedsciencenews.com/co2-on-the-brain-and-the-...
https://thinkprogress.org/exclusive-elevated-co2-levels-dire...
I've come to the conclusion 'stupidity' is not the issue; 'unthinking' is, and the specific sub-type is 'unable to apply logical analytical thinking'.
I have a relation who, when challenged that the way they're doing some task is the opposite of optimal, responds along the lines "I thought ...". In this case it is a sure sign that no logical analytical thinking took place.
Maybe the crux of the issue is that in general our societies have become so complex and fast-moving that technology, standard procedures (best practice), and fundamental measures of performance are changing so rapidly that very few individuals have the mental energy to keep up throughout their lifetime.
Some I'm sure have become tired of it and given up thinking altogether.
I would suspect many HN readers may have experienced this in their own highly technical fields alone.
For the general population who aren't - or don't want to be - interested in the world in general it's easy to deliberately avoid learning simple tasks and instead 'leave it to an expert' and continue in ignorance, or to expect someone else to have done it for 'convenience', or not want to attempt it because of the dangers due to 'health and safety'.
Here in the UK at least there's a very simple example of the culture behind this: the electric plugs on AC mains-powered equipment.
In the 1970s when a new item of white-goods for the kitchen arrived it was unlikely to have a plug fitted to the cable although some equipment came with a plug - you fitted it yourself and were expected to have the basic knowledge required to unscrew, strip the insulation from the cores, attach wires to poles, screw-down, insert fuse of specified rating, and screw back together. It often had a piece of card slid over the prongs with a diagram to help.
In the 1980s the cable almost always arrived with the cores cut to length and stripped and if you were buying a premium item the plug fitted by the supplier.
By the 2000s the plug was always fitted and more often than not it was molded onto the cable; and yet some of these still have the wiring diagram card attached. The plugs mostly no longer required the 'lid' removing to get to and replace the fuse - there is a captive sliding carrier that pops out when pried with a flat-blade screwdriver.
By the late 2000s the three metal prongs (earth longest, live and neutral slightly shorter) were encased in a plastic sheath which you have to remember to remove or else it won't fit into the wall socket.
Now, all of these incremental creeping changes can be seen as product improvements to provide greater convenience.
But the result is we now have several generations that have no idea about even the basics of the second most important technology in their lives: electricity (after water and food). They need an 'expert' to do it for them.
Ditto for basic plumbing skills, routine car maintenance, and more and more I notice even preparing basic meals, cooking and baking from raw unprocessed ingredients.
Oh, and a humorous anecdote on the subject of food: about 15 years ago a 17 year-old friend of mine was visiting for a week and I asked if she would like fish and chips (fried potatoes to the North Americans!). I grew up on a farm and so fetched the 25kg bag and selected some potatoes ready for peeling and chipping.
This 17 year old (who ate chips from chip-shops frequently) had no idea that to make chips required peeling and slicing raw potatoes and was incredulous at the process; she 'thought' chips just grew as long square pieces of potato - see: "unthinking".
I was left speechless that something that I considered so obvious and fundamental had escaped her for 17 years!
Multiply these examples up for every major and minor aspect of coping in a modern technology-based society and the result is the appearance of 'stupidity'.
However I do think it's something more than just the burden or unburden of our new technology. Logical thinking should be an universal trait, no matter what the environment is like.
However one thing which is eating into that equation, is logical thinking is almost never promoted in modern education. Even in a declining IQ environment, promoting and teaching logical thinking would reverse a lot of the seeming "stupidity" in our society.
But I still do think there is something more going on. It's not just (lack of) education.
I believe others of significance may be the exhaustion and stress many feel at the pace of life and coping with it.
On the educational side I think it very much depends on what culture, which country, which region, which politics, which teacher and even who your contemporaries are.
It's not about convenience, it's about selling a functioning and safe product
And yes I do agree the knowledge of replacing plugs is important and is getting lost, I didn't learn it by having to fit it to newly acquired equipment (rather by fixing equiment where that - or the cable - became faulty)
The design of UK plugs means that user replaceable ones are the same size and shape as moulded ones. Doing the same for Schuko plugs is harder so it makes sense that they went all-moulded earlier.
https://en.wikipedia.org/wiki/AC_power_plugs_and_sockets:_Br...
"UK Consumer Protection legislation requires that most domestic electrical goods sold must be provided with fitted plugs to BS 1363-1. These are usually, but not necessarily, non-rewirable."
The same applies to electrical wiring, I'm not allowed to do many of the tasks I would want with my wiring because I'm not "qualified". Nor was I allowed to fit my hot water tank because it is connected directly to the cold water supply.
I'm loathe to complain about these rules because in many ways we have improved our lives with health and safety legislation. It's comparatively rare for people to die during the course of their work or due to a fire in their home.
I bet fewer homes burn down from miswired plugs or plugs with improper fuses now, too.
I am occasionally surprised by how non-handy people are, but I also realize that being handy isn't actually that valuable. There is virtually no practical gain to be had from knowing how to replace a plug. At best you'll save a few dollars at some point. I am comfortable with wiring but have never replaced a plug. I doubt I ever will.
> This 17 year old (who ate chips from chip-shops frequently) had no idea that to make chips required peeling and slicing raw potatoes and was incredulous at the process; she 'thought' chips just grew as long square pieces of potato - see: "unthinking".
There have always been dumb (or unthinking) people. This isn't a recent change.
http://www.apa.org/research/action/intelligence-testing.aspx
http://www.independent.co.uk/news/science/iq-tests-are-funda...
https://blogs.scientificamerican.com/beautiful-minds/iq-test...
If intelligence were simple we'd know how to test for it. It isn't, and we don't. Not reliably, and certainly not in ways that are absolutely independent of culture and background.
The UK used to have a concept called "mental agility", which seems to be closer to the abilities measured by IQ than the much more complex quality psychologists call general intelligence.
You can have exceptional mental agility - the ability to remember and manipulate symbols and parse symbolic relationships quickly - and still be an utter idiot when it comes to dealing with some or all of reality.
A high IQ will not protect you from ideological beliefs, especially if you grow up with no exposure to other viewpoints, from a lack of mental openness (not to be confused with a lack of curiosity), from "moral" perspectives that are self-reinforcing prejudices, from poor socialisation, and so on.
"A recurrent fear during the past century is that the mean IQ level of populations will decline because persons with lower IQ scores have above-average fertility. Most microlevel data demonstrate such fertility differentials, but population IQ levels have risen rather than fallen. In this article, a simple two-sex model shows that negative fertility differentials are consistent with falling, rising, or constant IQ distributions. Under a wide variety of conditions, a constant pattern of fertility differentials will produce an unchanging, equilibrium distribution of IQ scores in the population. What matters for IQ trends is how the IQ distribution in one generation relates to the equilibrium distribution implied by that generation's fertility differentials. Intuition fails in this important area because it does not account for the macro structure within which micro results must be interpreted."
- http://www.journals.uchicago.edu/doi/10.1086/230135
Also note that there is "a strong inverse correlation between early life intelligence and mortality".
- https://en.wikipedia.org/wiki/Cognitive_epidemiology#Overall...
So there is no evolutionary pressure. Evolution is a (brutal) system of unfairness that represents everything that modern progressive values work against. This is something that will need reconciling (or many technologists will hope for genetic engineering I guess) or in the long term will not be sustainable.
Consider your children are on average genetically inferior to you. This is mathematically true. A society which uniformly has 2 children per person + 100% survival will regress. In fact it may take something closer to mediaval or even prehistoric reproductive outcomes to have positive evolutionary pressure. This could be many people having 4-5 children, with many other people who are 'unfit' not having children at all (either remaining childless or dying early).
The subsequent improvements in education,environment and nutrition have likely provided a dividend that masked a fall in underlying genetic intelligence. Naturally as those gains have been fully realised the underlying trend will reassert itself.
Please take another look at my second link: https://en.wikipedia.org/wiki/Cognitive_epidemiology#Overall...
If there's some analysis of evolutionary pressure over time I'd be interested to see it, although I'm not sure it can really be quantified like that.
'A strong link between cognitive ability and the risk of death.'
'A 15-point increase in intelligence was associated with a decreased risk of mortality of 32%.'
Wikipedia suffers a bit from not trying to be too neutral!!
Local cases of intelligence not helping with mortality/reproduction in todays society are not contradictory. This is the (dysgenic) thesis that intelligence does not help. Although increased mortality is perhaps a little harder to explain, but again hardly irreconcilable - I could speculate many plausible explanations.
To address your point, I feel it is intuitively true that we do not have positive evolutionary pressure. If indeed IQs are now falling despite the flynn effect then for intelligence at least here is the evidence for insufficient evolutionary pressure.
Evolution does not care about our ideology. If we don't account for it and nerf its edge, though forms of selection that don't cause suffering to conscious creatures, like embryo selection or genetic engineering, then we will have to wait for Malthus to provide sufficient selection pressure to ensue our survival or extinction. This fingers-in-ears approach to biological reality would be concerning if countries like Korea and China weren't poised to exploit embryo selection and genetic modification for increased health and IQ, thus likely forcing more reactionary countries like us in the west to adopt them, too.
https://2.bp.blogspot.com/-4qSTryry0so/WcAhygytvTI/AAAAAAAAS...
That means, in practice, your height outcome tends strongly toward a fairly narrow range around the predicted mean. I found it illuminating to visualize the pattern.
(The full article is http://infoproc.blogspot.ca/2017/09/accurate-genomic-predict...)
In his book, Flynn attributes part of the mysterious increase in IQ during the 20th century to the spread of general education and inculcation of scientific and logical modes of reasoning more broadly.
He recounts a story from Soviet anthropologists who travelled through Russia studying peasants at the beginning of the 20th century. An anthropologist presented a villager with a simple syllogism:
All swans are white. If I told you there was a swan in the next village over and sent you over to report its color for me. What color do you expect it to be?
Peasant's response: I don't know. I'd have to go check.
Which makes sense when you exist in a world in which you're operating mostly on the basis of personal relationships and trust is based on a person's word and status and not on abstract and institutionalized forms of knowledge. You'd be an idiot to trust the word of some stranger you just met.
But this guy probably did not do so well on the IQ test he was given.
In fact, check out this statement from Flynn's Wikipedia page:
Women, he argued, caught up to men in these nations as a result of exposure to modernity by entering the professions and being allowed greater educational access.
[1] Flynn, JR. The Flynn Effect: Rethinking intelligence and what affects it
[2] Flynn JR. Searching for justice: the discovery of IQ gains over time. Am Psychol 1999;54:5–20.
[3] Flynn JR, Weiss LG. American IQ Gains From 1932 to 2002: The WISC Subtests and Educational Progress. Int J Test 2007;7:209–24.
[4] Ree MJ, Earles JA. The ubiquitous productiveness of g. In: Rumsey MG, Walker CB, Harris JH, editors. Personnel selection and classification. Hillsdale, NJ: Lawrence Erl- baum; 1994. p. 127–36.
A while back someone asked Warren Buffet what he would be under more primitive circumstances. Buffet's reply was... "lion food".
In this case: Yes, We Get Wiser with Age (nautil.us) https://news.ycombinator.com/item?id=15346635
I mean testing different age cohorts, should it be that hard?