Thursday 29 September 2016

Goodbye Sweden: Can I have a quick reaction?


Journalists, being fed news of some dreadful event, are prone to ask their studio guests: “Can I have a quick reaction?” Almost always the Talking Head comes up with an off-the-cuff reaction, also known as an opinion, as to whether the event is the end of: a dictator/a government/a country/low cost oil/Western civilization/the planet.

I would not dream of criticising this response, particularly because in former times on TV I sometimes ventured minor versions of such a response. I have not yet been asked to comment in a public arena as to whether the finding that contemporary reaction times are slower than in times of yore indicates the decline and fall of our civilization. You know the story full well: the much championed Flynn effect suggests that good food, free education and proper drains have boosted our intelligence, as well they might have; the Woodley effect suggests we are slowing up, losing our intellectual sparkle, becoming more specialised in our abilities but very probably sinking into the mire of soggy stupidity.

Now we have some even more solid findings to favour The Woodley Effect. (By the way, Charles Murray, responsible for coining The Flynn Effect,  suggested to me that the contemporary lowering of intellect should be named in this way).

Guy Madison, Michael A. Woodley of Menie and Justus Sänger

Secular Slowing of Auditory Simple Reaction Time in Sweden (1959–1985) Front. Hum. Neurosci., 18 August 2016 |

They say: There are indications that simple reaction time might have slowed in Western populations, based on both cohort- and multi-study comparisons. A possible limitation of the latter method in particular is measurement error stemming from methods variance, which results from the fact that instruments and experimental conditions change over time and between studies. We therefore set out to measure the simple auditory reaction time (SRT) of 7,081 individuals (2,997 males and 4,084 females) born in Sweden 1959–1985 (subjects were aged between 27 and 54 years at time of measurement). Depending on age cut-offs and adjustment for aging related slowing of SRT, the data indicate that SRT has increased by between 3 and 16 ms in the 27 birth years covered in the present sample. This slowing is unlikely to be explained by attrition, which was evaluated by comparing the general intelligence × birth-year interactions and standard deviations for both male participants and dropouts, utilizing military conscript cognitive ability data. The present result is consistent with previous studies employing alternative methods, and may indicate the operation of several synergistic factors, such as recent micro-evolutionary trends favoring lower g in Sweden and the effects of industrially produced neurotoxic substances on peripheral nerve conduction velocity.

The authors have collected new data on a large sample, with 7081 usable respondents on which there was much background material from previous testing. They pursued the respondents with reminders, and tested them online, using the best available software to ensure consistent exposure and recording of responses. This cannot be the same as bringing them in to a standard experimental set up of reaction time equipment, but on the other hand it generates much higher numbers of respondents. They have also considered the impact of these variations in methods which, if anything, would obscure rather than reveal underlying trends.

Reaction times seem to slow up after 1970. The authors say:

We found clear trends toward slowing auditory SRT when birth year was regressed against year-on-year SRT means for the years 1959–1985. It is notable that even without adjustment for aging, the SRT speed of the oldest participants is about the same as that of the subsequent generation, whom in the late twenties are supposed to have the shortest SRTs of all age groups (Der and Deary, 2006).

the secular slowing trend was present in all cohort comparisons (males, females, and both sexes combined), and was significant across the entire range of birth years for both the males and the whole sample, but not for the females, who nonetheless exhibited an overall negative trend in SRT performance consistent with potential secular slowing.

A potential cause of the apparent slowing may be exposure to neurotoxic industrial by-products such as heavy metals (Silverman, 2010) and dioxins (ten Tusscher et al., 2014), which may reduce SRT performance via their effects on peripheral nerve conduction velocity. However, as Silverman notes, known neurotoxins have come under tight governmental regulation, emissions have tended to decrease, and serum levels of lead, for example, have decreased since 1970 in the USA (Silverman, 2010, p. 46).

Another possible cause of this trend may be relatively recent micro-evolutionary trends favoring lower g in the population of Sweden. Several studies have revealed that g and fertility are inversely related in the US and the UK (as reviewed in Woodley of Menie, 2015) among cohorts born as far back as the 1890s (Lynn and Van Court, 2004; Lynn, 2011). However, the relationship between g and fertility in Scandinavian countries is less well characterized. Only one study has attempted to examine these trends across birth cohorts in Sweden (Vining et al., 1988). Utilizing aggregate data on fertility and IQ for a mixed-sex sample of Swedish cohorts resident in Stockholm county and born between 1909 and 1940 from Vining et al. (1988), it was possible to reconstruct predicted generational changes in genotypic IQ (I.e., the heritable variance component of IQ) due to the changing patterns of selection (I.e., the correlation between IQ and fertility established for each cohort) for four cohorts (see Appendix 2 for details of the method).

Main result here, but see the full paper:


In sum, this is strongly suggestive of a slowing of reaction times in Sweden, itself suggesting a possible drop in mental alertness and intelligence in that country. If the Flynn effect were a deep-seated real improvement in functioning then one would expect faster reaction times, not slower. An alarming result, worthy of further testing and attention.


  1. I was sitting in a pub a few weeks ago. A gust of wind from the open window caught a sheet of paper on the table, and, just as it took off, I shot my arm out and grabbed it. OMG, said a young thing opposite, you've got fantastic reflexes.

    Are young things not used to people being quick? How do they field in the slips, for heaven's sake?

    My father also had lightning reflexes, but I thought nothing of it. Maybe they were commoner then?

  2. Santo piece und luv30 September 2016 at 01:55

    Reaction time correlates with intelligence... PERIOD.


    look ''reasonably positive'' to me

    Sir, you're reacting too fast to conclude that

    ''reduction of reaction time is clearly a sign of dysgenic effects in Sweden''

    Yes i know western world is suffering dysgenic effects by ''multiple'' reasons, from quasi--out of control immigration/colonization to the diferential fertility rates among [quantitative] cognitive layers of the natives itself.

    Think faster is the same than think correctly*


  3. Also see:
    Heller-Sahlgren, G. (2015a). Immigration helps explain Sweden’s school trouble. The Spectator, 10 August 2015. Retrieved from
    Heller-Sahlgren, G. (2015b). Real Finnish lessons. The true story of an education superpower. London: Centre for Policy Studies.

  4. This is a very informative blog with important information that all should read. 
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  5. Swedish used to dominate table-tennis..........

  6. The red sequence seems to be men and the blue sequence women, and the bars are 95% confidence intervals. Lead won't cut it as an explanation since it was introduced into gasoline in the 1920s but effects don't take off until the '70s. Perhaps the decline in men's speed is linked to the simultaneous depression of testosterone in men over the same period? Men's speeds from the 1985 birth cohort are comparable with same-age women's speeds, which aren't far off the 1959 female cohort. Women's speeds increased 1959-1972, then fell again through 1985. I suspect higher average testosterone in females of this period (perhaps only prenatally), which gains got washed away by the secular decline in testosterone for both sexes.
    The decline is huge, with the worst 2.5% reaction speeds of the pre-1977 males being better than the best 2.5% of the 1985 cohort.

    I'd like to see studies with choice reaction time or evoked EEG response; this would reduce the effect of peripheral nervous delays, which are higher for bigger people and don't correlate much with intelligence. The longer distance for nerve impulses to travel in men understates the CNS reaction speed advantage of men.

    Less seriously, though, this reminds me of an old SF novel by Theodore Sturgeon, I believe, where the amount of intelligence possible in a given brain depends on some quality of the interstellar medium through which the Earth is traveling. In the story the solar system enters a sort of invisible stupidity cloud and everybody drops 50 IQ points in a matter of days. Vernor Vinge used a similar idea, but with the regions of intelligence being generally lower toward the galactic core and super-AIs being hard to avoid toward the galactic rim.

  7. I was probably misremembering the plot of Poul Anderson's 1953 novel, Brain Wave. The Earth leaves a cloud for the first time since the dinosaurs died and everything with neurons becomes five times smarter.

    Here is a list of science fiction on intelligence, with brief notes: SF Encyclopedia: Intelligence.

  8. I also misinterpreted the confidence interval of the average as the range of reaction times in the sample; the real range is much larger.

  9. EH Thanks for your comments. Agree that choice reaction times would be interesting. However, Deary found that simple reaction times, against prediction from Jensen's work, were the better predictors of 11+ IQ. Best SF story on intelligence is Flowers for Algernon.

    1. Flowers for Algernon is a good one. You might want to look at screenwriter William Goldman's comments on adapting Flowers for Algernon in his books Adventures in the Screen Trade and Which Lie Did I Tell?: More Adventures in the Screen Trade. That was back in 1964, his first time out as a screenwriter. He got fired, but the movie was made, Charley(He also did The Princess Bride and scripts of other famous films.)

      Kurt Vonnegut's "Harrison Bergeron" was another favorite, also Vernor Vinge's "Bookworm, Run!" (1966, chimp with wireless neural link to supercomputer becomes intelligent, tries to escape from underground military research base), Tatja Grimm's World (superintelligent orphan comes to rule low-metal world; good speculative anthropology), A Fire Upon the Deep (mostly about a wolf-like acoustically linked pack-intelligence, but also about galactic refugees from a war of superintelligences, shipwrecked by a sudden shift in the "zones of thought"), A Deepness in the Sky (technological revolution among intelligent giant spiders, a human techno-slave culture using induced autism, and a believable sub-light speed starship culture), Fast Times at Fairmont High (a near-future California culture of high-school inventors working in VR, alongside "cured", rejuvenated but effectively memory-wiped Alzheimer's classmates. Actually, most of Vinge. Bruce Sterling's Schismatrix (genetic vs. electro-mechanical engineering cultures compete in the solar system during the protagonist's several life-phases over ~two centuries) and Charles Stross' Accelerando (as close as anybody has gotten to peering over the edge of the AI/augmented intelligence singularity - available free here ) are also landmarks in the field everyone should definitely read.

    2. Thank you for this extensive reading list!

  10. "Reaction times seem to slow up after 1970."
    So, since the onset of sexual revolution. Those two events cannot be related, or ...
    Actually, it looks like a multifactorial process with more and more factors adding up over time. Not only IQ but other traits as well.

  11. Mirrors immigration. Sweden had big peak in 1970 and increasing since then. I bet reaction times are much slower today. Here are the gov stats. Yellow line is immigration, grey is emigration,

  12. EH. All plots are both sexes together, the red is the same data as the blue but ageing-adjusted. We could of course compare the sexes, which is to some extent done in the two tables. The reason we aggregated the main result across the sexes is that the inter-participant variance is huge and we need large N to be able to say anything substantial in terms of secular change. Furthermore, we didn't find very much interesting to say about those comparisons, the main result of which is that women had a smaller decline. If we had a proper hypothesis for this, we could look further into it. I’m not sure if there is any support for the testosterone connection, but I'd like to know! I can’t recall reading anything about that.

  13. Forgive me for pointing this out again, but test scores on the most elite college entrance test in the USA, the SAT, have been declining for 50 years. I calculate slightly more than one IQ point per decade. And that despite a dumbing down of the tests themselves...If you go to The College Board's website, you can see for yourselves. The results are broken out by race, sex, education of parents, etc. I understand that other tests show a similar decline. As far as I can tell, the Flynn Effect is nonexistent, quite the contrary...

  14. It seems to me that Woodley of Menie is very definitely on to something major...

  15. Not about reaction time, but reversed Flynn effect was found Finland as well.