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[dupe] IQ scores have been in decline for cohorts born since 1975 (thetimes.co.uk)
43 points by sndean 35 days ago | hide | past | web | favorite | 64 comments

There seems to be a lot of negative bias around IQ tests based on social stigma. IQ tests are far from perfect and I think everyone agrees they are a woeful indicator of success.

However, I think improving IQ testing for the purposes of documenting human evolution is just as important as documenting fluctuations in disease, addiction, obesity and the like.

For example, there has been considerable scientific research that points to a noteable increase in IQ in America in the twenties due to increased iodine intake. If we are in-fact getting less intelligent, I think it would behove us to purse potential causes.

> IQ tests are far from perfect and I think everyone agrees they are a woeful indicator of success.

I don't know many people that agree with this. At least in my bubble, the great majority regard IQ tests as bunk and the rest regard IQ as just a very roundabout way of measuring the education level of a child's parents. (There's some disagreement whether the father's level of education is the most important factor [1] or the mother's education level is [2]).) It's only in a select few internet forums dominated by a select few types of people where IQ is taken seriously and even obsessed over.

Putting aside the wholly made-up g factor, what we've been seeing in the West for the last 30 years is rapidly increasing inequality in educational attainment. Severe cuts in education at both the public level and the private level (see, eg, the extraordinary rise of single mothers in both the US and EU and parents with multiple jobs) means that many children are simply getting less education than they did 30 years ago.

Note that this does not apply to the knowledge elite who go to extraordinary measures to educate their children. It's quite likely that the children of today's elite are the most educated children in the history of the planet. I know a few parents who have budgeted a million dollars for the education of each of their children.

The Flynn Effect was likely nothing more than the result of the extraordinary and broad-based increase in wealth we saw from 1900 to 1980. Since 1980 virtually all of the growth is being captured by the elites so it's not surprising at all that we'd see a similar reversal in the Flynn Effect.

[1] https://www.theguardian.com/society/2014/sep/23/fathers-educ...

[2] http://bigthink.com/ideafeed/mothers-education-level-at-time...

“Putting aside the wholly made-up g factor”

Why do you stoop to blatant lying?

“Research in the field of behavioral genetics has established that the construct of g is highly heritable. It has a number of other biological correlates, including brain size. It is also a significant predictor of individual differences in many social outcomes, particularly in education and employment. The most widely accepted contemporary theories of intelligence incorporate the g factor.[1]”

“The practical validity of g as a predictor of educational, economic, and social outcomes is more far-ranging and universal than that of any other known psychological variable. The validity of g is greater the greater the complexity of the task.[2][3]”

[1] Neisser et al. 1996

[2] Jensen 1998, 270

[3] Gottfredson 2002

I believe that foremost it's pattern recognition and abstraction that is tested in IQ tests. No matter in what field people who excel at pattern recognition or abstraction, or both are considered very talented. Yet, other peers in the same field might be competent enough for that field, but they lack talent, the ability to go beyond their general competency in that field. That means, you don't have to have genius level IQ to do well in science, formal training and determination are enough in most cases. High IQ in contrast does not guarantee that the person knows how to put their talents to use, without formal training that is. A bearer of a PhD diploma might still be dumb as a rock, but thanks to formal training, it doesn't seems as obvious. On the other hand, there are people who might be considered low IQ, because they were "too dumb" even for high school, but actually have genius level IQ. It wasn't obvious that they were intelligent, because their abilities weren't seen as such, as they couldn't solve the easiest stuff.

It would be interesting to see how chemicals leached from plastics introduced in the 70s affect IQ.

Then I guess you could also look at the removal of lead from car exhaust gases, (generally considered a good thing).

I couldn’t read the full article due to the paywall and there’s no nice way to put this bit but is the drop in score due to a decline in the number of people with high IQ or because people with low IQ are surviving longer in childhood where previously they might not?

And it would be interesting too to correlate it with analysis of our DNA.

IQ is the last taboo. We don't want it to matter for socioeconomic success in life. We don't want it to be inherited to such a high degree that environmental factors like parenting and education hardly matters. Its all too depressing. People are born unequal, and there is little that can be done about it.

IQ correlation studies:

Same person (tested twice) .95

Identical twins—Reared together .86

Unrelated children—Reared together—Adults .04


The article is pay-walled for me - but based on the title: people that take IQ tests also have changed. The value and significance of IQ tests have definitely shifted since 1975 so that could be a big reason.

If it's true, as the article said, that this is occurring within the same families, that is to say within Norwegian families, rather than within new migrant families, then this result is highly disturbing.

If the reversal of the Flynn effect can be described as just a changing definition of intelligence, why are we so sure that the Flynn effect represented real intellectual gains?

Flynn himself does not believe that the Flynn effect represented real intellectual gains.

For any test, your grade is usually based on: * Your form on that day (good day/bad day whatever) * Your competence * Test taking ability (TTA)

The first one can result in pretty large fluctuations, though on the population level (what the Flynn effect measures) it should not matter. Competence usually means "knows the subject", for an IQ test this would (ideally) be "is smart". TTA is either "is prepared for the test" or "knows how to make educated guesses".

It is believed that the Flynn effect largely results from two factors: * Some parts of the population were severely malnourished 50-100 years ago which hindered their brain development. * Improved TTA

The first one would be a real gain (of intelligence), though with limited capability to expand upon, as these days almost no one (in US/Europe at least) is malnourished enough to allow for further gains at the population level

The second is not a gain of intelligence though it is a gain of competence, just not the kind that we want to measure with an IQ test.

As there are not many reasons to believe, that the current decline is due to nourishment/TTA, it may be that those are constant but actual intelligence is on decline.

Well, we're not so sure the reversal is " just a changing definition of intelligence" either...

Setting aside the click-baity title.

The world today is way different than when we came up with IQ tests. Yes there might be a corellation between how good you do on an IQ test and how “smart” you are but I think over and over again your background/upbringing had been show to influence that more than your “smartness”.

If the question is: do we think in different way than we did 50 years ago? I think the answer is a stong yes.

The technology and the tools we have today enable us to do things that were unconcievable 50 years ago.

Is this good? Is this bad? The truth is that human beings are (and always were) pretty limited. Our hardware sucks. The things that enables us are tools and our use of tools. As we get better tools we do better and better and our attention is focused on different things. I would argue that today we are smarter than we’ve ever been and we are getting smarter each day by using more and more powerful tools.

I thought it had been shown over and over again that Iq had more to do with it than your upbringing?

it has. there’s twin studies where they are adopted to differnt families and yet end up scoring the same on IQ tests later in life and end up with similar levels of educational attainment and income etc

If I used to do arithmetic mentally or by hand and you gave me a basic adding calculator that let me do the math more quickly, would my increased productivity really signify anything w.r.t. my intelligence?

Technology is amplifier, not a replacement.

It can be both.

>Yes there might be a corellation between how good you do on an IQ test and how “smart” you are but I think over and over again your background/upbringing had been show to influence that more than your “smartness”.

The background/upbringing influences one's performance in IQ tests too, so the point is moot.

>If the question is: do we think in different way than we did 50 years ago? I think the answer is a stong yes.

Not in the slightest.

>The technology and the tools we have today enable us to do things that were unconcievable 50 years ago.

Which is neither here not there when it comes to intelligence. Plus we still do things we did 50 and 100 and 100000 years ago and still need to be good at them...

Haha. "IQ". A numbered score given after answering a few short problems administered in a high-pressure situation. Oh, IQ; woe.

If I take a second to sit down with my peers (20's) and really talk, all sorts of funny things come out of their mouths which really invite me to think about intelligence in a different way. You wouldn't believe the insights-- from every angle possible.

Who gives a damn about IQ anymore? Who is anybody to equate it with intelligence? What is intelligence? I say: you don't know and I don't know, and who cares!

A real IQ test (i.e., WAIS-IV or similar) is a lot more than just a few short problems, it takes several hours and is done one on one with a trained psychologist.

The test used by Mensa (as an example many think about when they hear IQ test) is a simple test that has shown reasonably stable correlation with IQ, but it is not a real IQ test.

>after answering a few short problems administered in a high-pressure situation

So like the kind of situations a person finds themselves all the time throughout their lives?

IQ is just a proxy, so seeing it as such I don't have such high expectations because I try not to confuse it with intelligence per se.

This happens all the time, GDP is another fantastic example.

Let's try to educate people that proxies are not the real thing, not condemn the measures - because it's not their fault :-)

I'm confused. Is the 100 IQ value's meaning, "average intelligence" (it's also supposed to be the median value, half of the population has an IQ around 100) stuck to a single point in the past for a certain cohort? How can IQ scores decline?

Scores are periodically renormalized to a new sample to keep 100 the median, but you can normalize to a single baseline to compare across time.

Other discussion in the past 1-2 days:


Paywalled link.

Source seems to be: http://www.pnas.org/content/early/2018/06/05/1718793115

Key piece from abstract: "Using administrative register data and cognitive ability scores from military conscription data covering three decades of Norwegian birth cohorts (1962–1991), we show that [...]"

There may be some changes in what kinds of people sign up for the military as the cold war cooled down and disappeared.

I believe Norway has had mandatory conscription for all males, so sign up bias shouldn't be a factor.

Good point.

But then, WP says " In practice recruits are not forced to serve, but if the armed forces see an unmotivated person fit for military service, they can force them to serve. About 60,000 Norwegians are available for conscription every year, but only 8,000 to 10,000 are conscripted."

So in practice my argument stands, with the additional factor that playing dumb in an iq test might be a good way to escape the "fit but unmotivated" categorisation.

It's official; this generation dumber! Now get off my lawn and listen to some real music!

jk, kids today outpace me daily.

PS I wasn't kidding about the music!

Sorry was trying to be funny.

Non pay walled link: https://pastebin.com/54h7zF0b

Article is paywalled. How about this for a hot take, based on the title alone: there is an overlap of an IQ boosting effect from environment (better nutrition, health care etc.) and an IQ depressing effect from genetics (e.g. increasing years of education depressing fertility of high-IQ people, or increased mutational loads from all those carcinogens California tried to warn us about, or whatever). For decades, the IQ boosting effect dominated (resulting in the Flynn effect), but now it's basically maxed out, and the IQ depressing effect drives the trend.

Article was not paywalled for me the first time I looked. As I recall, it claimed that the measured fall in IQ test results cannot be explained by genetics because the same fall was observed within particular families. In any case, the fall seems far too big to be explained by genetics, so probably it's caused by education, I would guess.

There probably is a much smaller, perhaps not yet measurable, fall caused by genetics. I tried to submit an Economist article on that. (Can you see it under https://news.ycombinator.com/submitted?id=bloak ?)

It appears that when an article gets many hits at a time a paywall is triggered. So, the title is clickbaity, then it gets submitted to HN, a few people read it, then suddenly it's paywalled. Right. Moving on, nothing to see here.

inb4 anecdotes like “I have a friend with a PhD in applied chemistry with an IQ of 73”

Stop submitting paywalled articles. It's really annoying.

Since primary school in the 1960s and 1970s I've refused to do IQ, and I don't intend doing IQ: I think its bad social policy, the theory may work for some people but its used in pretty awful ways once it hits politics, school policy and budget.

That said, I think there are two pretty clear choices which then lead to more choices

Either this is a thing, and we should worry about it, Or, its not a thing, and we don't have to worry. The comments in the article about the Flynn effect and the ability to measure IQ in a changing world of "what is intelligence" goes to the second case: its too early to worry.

But, if this turns out to be something environmental or educational, much as (on the positive side) removing lead was for it's effect on behaviour, mood and intelligence, then we need to worry about this.

Personally, I don't yet think this is a thing. All the signs I see from the peak of 57 meritorious, unmeasured-in-IQ years, is that younger people are smarter than me, and more capable than me of applied thought.

"I don't believe it, yet"

> Younger people are smarter than me

I feel this too. I'm in my twenties and the small children scare me with their brilliance sometimes. I am excited to see those little guys grow up. I am convinced they will be the first generation to ask, in full, "what should we do?" rather than, "what can we do?". Very excited.

Heh, well I don't feel like the small children are smarter than me. But having raised a smart kid I always find it amusing then an adult talks to her like a kid, then gets counter attacked by a bright kid who is used to adults talking to kids like they are idiots.

Kids are plenty smart, they just don't have the experience, but I find they can handle complex ideas just as well as adults, if given a chance. Similarly trying to sugar coat things like violence and death doesn't really help, and while difficult they seem to deal with it as well as adults.

Really? I look at kids these days and see hyperactive idiots with access to all the knowledge in the world but who choose to watch fuzzes of color that nearly give me seizures. I'm not saying older generations were better just that this one isn't.

Maybe we all show selection bias because I see people who see signals in what I call noise, and people who have moved on from social media leaving it to snarky older people.

Maybe the next generation has both smarter smart kids and dumber dumb kids? Knowing the net change and distribution of intelligence would be nice.

Does anyone have kids that seem less smart than they were at that age? Asking for a friend.

It depends if the age of the kids and what you want to measure as smart.

Kids, when growing, learn stuff, but not in the « same order » as other kids. Some gonna walk early (my sister was 8 1/2 months old), some gonna talk early (my parents told me I was able to discuss with adults at the age of 17 months) etc.. And it’s true for all the abilities. Read soon, draw soon.

It won’t mean that they’ll be good at it later. Just they assimilate it sooner than others.

So some abilities make a kid shines when another might not. Doesn’t mean they won’t be smart later.

That's an interesting concept, that kids naturally learn not in the same order. Implicates an issue with school systems since curricula are rather rigidly sequenced.

I do. I was not a child prodigy, but still, I was (am) significantly high on the "smartness" scale. My kid is definitely "not like me". I don't see any problem with it; I don't belong to a culture where success in absolute terms is the ultimate goal in life, so, "smartness" (which of course is a narrow definition) is just one of many, many factors.

When you see that your kid isn't as smart as you were it would seem to be important to instill in them the need to really strive since success is probably not going to come easy for them but they can still do well. Wondering how smart parents do that, so I can tell my friend.

You're making a few assumption that don't hold true in my culture/philosophy:

1. a specific type of success 2. the need for such type of success

I personally don't value any of them, and in my culture they're not pushed hard, either.

If I would be in that culture and philosophy, definitely, that would be a very troublesome situation, as it would put lots of achievement pressure on the children (and likely failure to meet the "success" of the parent.

I guess there is literature about the relationship between genius parents (in a strict sense, so not my case) and children, since probably, very similar mechanics develop.

Success can only be defined with respect to a particular goal. We all have different goals in life.

Goals may change, so it's good to keep one's options open, but to "instill" anything in a child is hard. With some teenagers the best thing to do might be to ban them from reading and studying and punish them whenever you catch them doing their homework. They might then do those things in secret just to spite you, and then they might at least have the option of going to university.

Definitely. Of course, different people have different skill sets, so it's hard to make a reliable assessment of overall intelligence. Nevertheless, my children seem less intelligent than me, overall, and I seem less intelligent than my father, overall. I believe it's called "regression towards the mean".

That's the joke my dad told me. He got a first. We all got seconds. Case closed.

I'm seeing this myself, with an unusual calibration. My kids are learning music, as I did when I was a kid. The classical repertoire has not changed much since then, so I know what level they have reached compared to me at the same age. Granted, much about music is subjective, but some of it can't be faked, and so I can gauge my kids according to fairly objective measures, and they are far ahead of where I was at the same age.

Could this be because they enjoy the advantage of your mentorship ? I took personal charge of the education of my niece and by age 7 she was more proficient in some areas of maths than I was at 12.

That's certainly possible. I also think that music teaching has improved, and my kids are growing up in a town that's crawling with great musicians -- part of why we live here.

In our house, the parent/child dynamic wasn't conducive to me teaching my kids. That's kind of luck-of-the-draw. So they go to private teachers. But I suspect our love of music, and having it be part of our lives, has rubbed off on them.

Are these kids smarter or is their environment “better” in such ways thar allows them to be brilliant?

My money is firmly on the environment.

Does it matter?

My daughter (8 years) speaks, reads, and writes three languages fluent. It's scary sometimes.

How is she exposed to three languages?

Maybe by being raised in a bi-lingual family where the parents did not speak each other's language when they met? This is how it is for me and my children: I speak English with my wife and Dutch with my children. She speaks Swedish with them, English with me. I have no problems speaking Swedish but things just ended up this way and it'd feel strange to speak Swedish to her. I often do speak Swedish to my children when there are Swedes around so they can understand as well but for the rest it is Dutch which counts. This has led to them speaking Swedish, Dutch and English at a young age (my youngest daughter is 6, she speaks Swedish and Dutch and is coming along quite well in English (as in 'speaking', she already understands most of what is being said). The younger a child learns a language, the easier it is for them so I can only see advantages in this approach. My oldest daughter now goes to a school with a 'French' profile so she'll end up speaking at least 4 languages, one of them (French) a romance language [1] for some contrast to the three Germanic languages (Swedish, Dutch and English).

In other words, speak your native language with your children, you'll be doing them a favour. Just make sure they learn the language of the land as well, preferably at home before they go to school.

[1] https://simple.wikipedia.org/wiki/Romance_languages

In practice the local language always becomes the child's strongest language, whatever you do, so if the local language is the language of the land then you don't need to "make sure they learn the language of the land": it will look after itself. Your problem will be to prevent the local language from completely replacing the other languages.

The local language is not always the language of the land. In parts of Sweden the local language is Arabic, children growing up there sometimes don't get to speak Swedish before they go to primary school at the age of 7. They could have the bad luck of ending up at a pre-school where nobody speaks Swedish [1] which makes it even harder for them to learn the language of the land. From the article:

"På Missansia förskola har alla barn utom ett vårdnadshavare med ett annat modersmål än svenska. Enda stället där de kan tala eller uppmuntras att utveckla svenska är därför i förskolan. Utbildningsnämnden konstaterar därför att "om då förskolan enbart har personal i småbarnsgruppen som inte kan svenska får dessa barn ingen uppmuntran i det svenska språket".

Nämnden utrycker också en oro över att barnen riskerar att få en sämre start än sina klasskamrater i skolan, vilket kan medföra en sämre kunskapsutveckling och ett utanförskap.

– Förskolan ska bedrivas på svenska, det är extra viktigt när de talar sitt modersmål hemma. Grunden är att vi måste garantera barns rätt till en bra förskola, säger Olle Johansson."

...which translates to:

"At Missansia pre-school all children except for one have parents (the word used is 'vårdnadshavare' which means 'custodians') with a native tongue other than Swedish. This means the only place where they can speak or be motivated to develop Swedish is pre-school. The school board therefore concludes that "if pre-school only has personnel (in the group for the youngest children) who can not speak Swedish this means those children do no get any motivation in the Swedish language"

The board also is worried that the children will have a worse start than their classmates in school which can lead to worse results and segregation.

– Pre-school has to be run in Swedish, this is extra important when they speak their native tongue at home. The reason is that we have to guarantee the child's right to a good pre-school, says Olle Johansson.

[1] http://nt.se/nyheter/norrkoping/ingen-i-personalen-kunde-sve...


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