The Flynn Effect

Tyler Cowen summarizes a few of the more surprising aspects of the Flynn effect, which refers to the phenomenon of rising scores on mental ability tests (like the IQ test) from one generation to the next:

1. Non-verbal IQ has risen more rapidly than has verbal IQ.

2. Performance gains are smallest on the most culturally specific tests, and largest on the most abstract tests.

3. Performance gains, as they occur over time, are roughly constant for all age groups.

4. Problem-solving abilities have seen the biggest performance gains.

Here's the paper from which these factoids have been drawn.

What do you make of the Flynn effect? Are people actually getting smarter? Or are we just getting better at taking intelligence tests?

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Is it possible that as our society values thinking ability over physical ability, our brains are adapting as well? In a Darwinian sense, we improve the aspects of ourselves that will prove most beneficial within our society, right? So over the past 100 years physical labor has taken a back seat to intelligence and thinking ability. Wouldn't it make sense for our brains to adapt to that change?

We were always told that the IQ test would be given but once in a lifetime. Since IQ would never change, there could be no reason to justify a retest.

We who learned a thing or two since childhood began asking about test reliability, including test-retest reliability, and that's when the wheels started coming off.

It turns out that if you are given the IQ test a number of times, whether the number is large or small, or if the period of testing is long or short, your scores keep rising. None of the theory behind the test allows for this phenomenon.

It also turns out that the IQ norming model has to be adjusted over the years, since the population keeps driving the scores up. The theory does not allow this either.

The question is where is the fault? Are people inherently defective because they keep performing wrong? Or is the theory behind the testing perhaps imperfect?

I thought it was rather uncontroversial that the Flynn effect was limited to test-taking improvement since it doesn't increase the g measure of intelligence. I think it is also important to point out that flynn effect seems to have peaked in a number of advanced nations, see the flynn effect's wiki entry. Perhaps it is a consequence of national development, compulsory education, but one that has now reached it's limits in more advanced countries.

By le adulte terrible (not verified) on 15 Aug 2007 #permalink

Mike Arauz, I hope that comment is tongue-in-cheek. If American society "values" intelligence over physical prowess, we sure have a funny way of showing it. Our President is a fucking moron, tall and attractive people have a demonstrable advantage in white-collar careers and salaries, and the most-highly-paid individuals in our society are professional athletes.

If you picked 100 people up off the street in any major city in the US and asked them who they admired more, Michael Jordan, Albert Einstein, Tiger Woods, Jerry Falwell, Paris Hilton, or James Watson, I bet Tiger would come first, Mike would be #2, Falwell would be #3, and 95 of them wouldn't know who Watson is.

Don't be silly, tekel. Albert Einstein legally changed his name to Albert Brooks. Brooks was born Albert Lawrence Einstein in Beverly Hills, Los Angeles, California, into a Jewish American family, and attended Beverly Hills High School. His father, Harry Einstein, was a comedian who performed on Eddie Cantor's radio program and was known as Parkyarkarkus. His mother was actress Thelma Leeds (born Thelma Goodman). His brother is comedic actor Bob Einstein, better known by his stage name "Super Dave Osborne".

And everyone knows about James Watson, born 16 April 1970, in Glasgow, Scotland, whose acting roles include:

1 The Study of Bunkers & Mounds in a Temperate Climate (Relatively Speaking) (2007) .... Chris
2 Take 3 Girls (2006) .... Bouncer 1
3 Summer Solstice (2005) (TV) .... Dominic
... aka Rosamunde Pilcher - Zauber der Liebe (Germany)
4 A Woman in Winter (2005) .... Taxi driver
5 Red Rose (2004) .... Lewars
6 The Bone Hunter (2003) .... Fingal
7 If Silence Should End (2002) .... Malcolm
8 Prince William (2002) (TV) .... Sqiggy Clavell
9 The Winter Warrior (2002) .... Fingal
10 "King Jamie and the Angel" (2002) (mini) TV Series .... Soldier
11 The Hawk & the Dove (2001) .... Micheal
12 "Dune" (2000) (mini) TV Series .... Duncan Idaho
... aka Frank Herbert's Dune (USA: complete title)
... aka Frank Herbert's Dune - Der W�stenplanet (Germany)
... aka W�stenplanet, Der (Germany)
13 Ratcatcher (1999) .... Bus Driver
... aka Ratcatcher (France)
14 Blind Date (1999) .... Brien
15 "Mystic Knights of Tir Na Nog" .... Tidgh (1 episode, 1998)
... aka Saban's Mystic Knights of Tir Na Nog (USA: complete title)
- Night of the Spirits (1998) TV Episode .... Tidgh
16 Biological Maintenance Department (1997) (as Jimmy Watson) .... Jim
17 Before I Sleep (1997) .... Patient

"If American society "values" intelligence over physical prowess, we sure have a funny way of showing it. "

Not really. There are far more office and administrative jobs today and far fewer laboring jobs, compared to the early 20C. Most people do a lot of problem solving at work. They may be small problems ("How do I get the photocopier to print double-sided?") but so are the ones in IQ tests.

Mike Arauz (the first commenter above,I believe) is wondering if we are "adapting" towards more intelligence in just 100 years. I do not think that 100 years us long enough for such a change to appear in human beings under very little pressure to change in that way.

I think it is more likely that our nervous systems just work better because they are allowed to funcion "optimally" with improved nutrition and, overall, better, more pleasant, and easier living conditions.

James Watson? The trouble is, there are several people with that name. But to my knowledge there is only one Francis Crick, who would have made a more telling example.

In a Darwinian sense, we improve the aspects of ourselves that will prove most beneficial within our society, right? So over the past 100 years physical labor has taken a back seat to intelligence and thinking ability. Wouldn't it make sense for our brains to adapt to that change?

This is not how evolution works. You implicitly refer here to natural selection acting on variable phenotypes, where phenotype variation is at least partly due to genetic variability. Your implication is that people with "thinking ability" have been selected for.

For this to have happened, people with genetic makeup related to "thinking ability" would have had to have been, essentially, reproducing more successfully - having more children who themselves survived to reproductive age, relative to other members of the population.

In reality, there has probably been little or no such selection. The descendents of people who lived in 1900 are far less likely to do physical labor than their ancestors were, but their ancestors were just as capable of being sedentary - they just didn't get the opportunity.

I should add that the concept of "g" remains quite controversial, and for good reason.

The construct of g is not controversial, it's very well documented. It's an abstraction of an abstraction (of an abstraction), but it emerges pretty well in any decent cognitive ability data set when you run it through principal components analysis, and statistically speaking it is well-founded. The applicability of IQ testing as a predictor of job performance, life achievement, happiness, success, social prestige, criminality or any of a number of other environmentally-dependent variables is what is controversial. And that usually only occurs with sophomore researchers and the folks who are out to disparage the utility/construct of IQ testing.

So over the past 100 years physical labor has taken a back seat to intelligence and thinking ability.

If American society "values" intelligence over physical prowess, we sure have a funny way of showing it.

Not that selection is necessarily at work, but even if it is, the stimulus needn't have started recently. Perhaps the intelligence increase we're seeing now (if it's even real) is just part of a very gradual change that's been going on since prehistoric hunter-gatherers settled down in villages and divided their labor. Compared with the Ice Age, even the modern White House looks like a perpetual contest of wits.

Epistaxis: I'm not sure if there's any evidence that humans are substantially more intelligent now than, say, 10,000 years ago. However, we do have a rather substantial accumulation of knowledge. Maybe as an entire species we have more smarts, but it may be only because we've capitalized on the collective intelligence of billions of people, past and present.

True, there is only one Francis Crick. But he wasn't American, so it's even less likely that our sample of 100 random sportsfans will know what he's famous for. I could have suggested Alan Turing or Louis Brandeis... my theory is that it won't matter who the intellectual giant actually is. And for the sports star, it doesn't really matter either- you could probably even pick someone from a "sport" like NASCAR and the rankings won't change- Tiger #1, MJ #2, Jesus pimp #3.

And just because there are more office jobs today doesn't mean that we "value" intellect more. Making double-sided copies is emphatically not the same thing as theoretical physics.

Not that selection is necessarily at work, but even if it is, the stimulus needn't have started recently. Perhaps the intelligence increase we're seeing now (if it's even real) is just part of a very gradual change that's been going on since prehistoric hunter-gatherers settled down in villages and divided their labor. Compared with the Ice Age, even the modern White House looks like a perpetual contest of wits.

Others have already pointed this out, but anyway - it is obvious that big brain size was rapidly selected for in the hominid lineages. However, there is no obvious evidence that "higher intelligence" has been genetically selected for in humans over the last 10,000 years.

Differences in environmentally determined learning can often produce the impression that individuals differ in "intelligence. So of course a modern human would look like (and operationally speaking, actually be) a helpless idiot in an ice age environment, and vice versa.

The construct of g is not controversial, it's very well documented. It's an abstraction of an abstraction (of an abstraction), but it emerges pretty well in any decent cognitive ability data set when you run it through principal components analysis, and statistically speaking it is well-founded.

I guess I should have said that the usefulness of the concept is controversial.

Any definition of "g" that I ever saw was essentially an expression of the fact that an individual's scores on similar written/picture tests of a cluster of somewhat similar cognitive traits tend to correlate highly with one another. (Not just IQ and SAT, but other similar academic and bureaucratic tests, like police exams and the like.)

That's about as surprising as the fact that playing one musical instrument is associated with being to learn other musical instruments.

So in essence, "g" is just an easily predicted correlation between individual scores on similar tests (which measure cognitive traits but also motivation, attention, learned test-taking strategies, etc). I guess in this sense its existence is not controversial

I have no problem with IQ tests when used properly, by the way. They can be very useful. A high or normal score rules out all sorts of things in certain clinical or educational situations. An unexpectedly low score can be, albeit with less reliability, a warning of an emerging cognitive problem.

Using "IQ score" to imply expertise across topics in which one is ignorant, to overcompensate for lack of actual accomplishment, or bolster ethnic bigotries, is silly, and in the latter case unethical, of course. For whatever reason, the concept of "g" seems to be especially popular among those who abuse IQ testing in these ways.

The Flynn effect, suggests that intelligence can increase, and hints at the fact, that there exist significant inter-individual differences in higher order cognitive skills. More importantly, it invites the hypothesis that people attain (relative) Gf peaks, at different ages. (perhaps between the late teens and mid-20's). The most recent material, from various authors, suggests that n-back training and schooling have immediate, measureable, positive effects on Gf. Suzanne Jaeggi's explanation to this, was that Working memory training, trains circuits that overlap with Gf circuits. It's interesting because, Glial cells, which have long been thought to be only provide nutrition to neurons, have recently been shown to play a role in effecting the firing rate, in both local and distant neuronal circuits. Perhaps this is the direct effect of WM training (and/or simply ruminating). Where there is an enhancement of neuronal pockets in the PFC, ultimately, allowing for measurable (and meaningful) improvements in Fluid skills.

Although for the vast majority of the population, the effects of differential development, would not be noticable, their may be atypical individuals (I would recommend seeing fluid intelligence and Asperger's syndrome. Although 'atypical' may not apply exclusively to high functioning autistics). Where within at least some temporal frame, such a person would be peering into the future, by essentially emulating the processing of high IQ individuals. But even if such a scenario does not hold, the documented effects of WM training, should still come to question the long-held (and rather convenient) assumptions of the cognitive elite.

By john zadel (not verified) on 25 Feb 2010 #permalink