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Did the Victorians have faster reactions?

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Re: Did the Victorians have faster reactions?

#21

The papers abstract is a bit more interesting than this summary. It looks like they compared 14 studies of reaction time over decades, not just Galtons: https://www.sciencedirect.com/science/article/pii/S016028961... >The Victorian era was marked by an explosion of innovation and genius, per capita rates of which appear to have declined subsequently. The presence of dysgenic fertility for IQ amongst Western nations,…

> may have resulted from the presence of dysgenic fertility The effects might be interesting, but it seems like an entirely unsupported logical leap to attribute any effect to this cause.

Other way round : the author is a eugenicist looking for evidence. https://rationalwiki.org/wiki/Michael_A._Woodley_of_Menie

Re: Did the Victorians have faster reactions?

#22
post #17

Earlier quoted context omitted.

Reaction times are strongly correlated with IQ which, in turn, has strong inverse correlations with many of the characteristics for people who are, and have been, reproducing the most. The paper proposes this, 'dysgenic fertility', as a possible explanation. As an aside this is not an implicit reference to e.g. Africa. This problem exists on an international and intranational level. E.g. in the US people who have hou…

IQs in the developed world seem to have started to substantially decline with no viable convenient explanation. Maybe what's happening is that IQ has been declining for a longer time, but the gains in health and nutrition were offsetting the effect. An interesting variable to compare to is life expectancy, which is a proxy for health. Its growth in western countries has been slowing and in the US it has even started…

We do not even have good enough data to support IQ results in a single generation related to this... (there are problems when checking across cultures) Additionally, the tests were modified over time.

Is the reaction test the same? Was it checked for reproducibility? Has an alternative hypothesis of slower muscle speed been excluded?

So, drawing any conclusion from these numbers is very, very risky, even riskier over time - unless you somehow invent time travel and give Victorian era people the exact same test we give people now.

Remember, IQ tests are graded across average in a generation...

Re: Did the Victorians have faster reactions?

#24

The papers abstract is a bit more interesting than this summary. It looks like they compared 14 studies of reaction time over decades, not just Galtons: https://www.sciencedirect.com/science/article/pii/S016028961... >The Victorian era was marked by an explosion of innovation and genius, per capita rates of which appear to have declined subsequently. The presence of dysgenic fertility for IQ amongst Western nations,…

Did he even bother checking error bars due to multiple test correction when verifying the correlations in pooled data?

We could ask Cochrane what they find. They tend to use many more studies than 14 as input with clear inclusion and exclusion criteria.

I suspect the author misuses statistics and fails to check internal and external validity of his measures.

How did he even get the real IQ points when the test had been changed and regraded about every 20 years? How does he convert the numbers to g? Is it general or slanted? Is his measure verified to be consistent even in a single generation across cultures? Etc.

Unfortunately, the other paper is behind the paywall.

Re: Did the Victorians have faster reactions?

#25
post #17

Earlier quoted context omitted.

IQs in the developed world seem to have started to substantially decline with no viable convenient explanation. Maybe what's happening is that IQ has been declining for a longer time, but the gains in health and nutrition were offsetting the effect. An interesting variable to compare to is life expectancy, which is a proxy for health. Its growth in western countries has been slowing and in the US it has even started…

We do not even have good enough data to support IQ results in a single generation related to this... (there are problems when checking across cultures) Additionally, the tests were modified over time. Is the reaction test the same? Was it checked for reproducibility? Has an alternative hypothesis of slower muscle speed been excluded? So, drawing any conclusion from these numbers is very, very risky, even riskier over…

One standard measurement of IQ is the Stanford-Binet exam. It's been around since 1916 with extensive concern given to consistency in the 5 updates it has received over the century. And that consistency is determined through thousands of trials with demographically representative samples to avoid predictable issues like a self selection bias in testing.

But like you mention the tricky part is that IQ is measured across an average in a generation. The mean is normalized to 100 with a standard deviation of about 15 points. An IQ of 115 does not mean you 'scored' 115 in a vacuum, it means you performed better than 84% of people. The idea that IQ would substantially increase or decrease for an entire population over very short periods of time (thus changing the meaning, in a vacuum, of e.g. 115 IQ over short periods of time time) was surprising, and that's precisely what the Flynn Effect [1] is. However that change is precisely measurable and enables researchers to produce comparable values between generations.

[1] - https://en.wikipedia.org/wiki/Flynn_effect

Re: Did the Victorians have faster reactions?

#26
post #13

The papers abstract is a bit more interesting than this summary. It looks like they compared 14 studies of reaction time over decades, not just Galtons: https://www.sciencedirect.com/science/article/pii/S016028961... >The Victorian era was marked by an explosion of innovation and genius, per capita rates of which appear to have declined subsequently. The presence of dysgenic fertility for IQ amongst Western nations,…

One complaint IIRC was that the Victorian sample might have been more skewed towards the elite than the current ones -- people attending science lectures, or something. I haven't read the paper linked, Woodley-teNijenhuis-Murphy, but do they address this?

Oh boy, where do we even begin... Let's try this: http://archive.is/YcIDb

Re: Did the Victorians have faster reactions?

#27

Interesting, and perhaps indicative of different environmental conditions now? I wonder if there's a toxicological or immunological explanation, or whether it's simply due to differing recreational and activity choices.

Reaction times are strongly correlated with IQ which, in turn, has strong inverse correlations with many of the characteristics for people who are, and have been, reproducing the most. The paper proposes this, 'dysgenic fertility', as a possible explanation. As an aside this is not an implicit reference to e.g. Africa. This problem exists on an international and intranational level. E.g. in the US people who have hou…

Re: correlation of income to fertility. The causation could perhaps go the other way when looked at as potentially genetic preference for smaller families. Smaller families mean children receive a larger percentage of their parents' time and money which will give them an advantage over children whose parents divide their resources among more children. Of course effective birth control is still so new that it throws a wrench in this argument.

Re: Did the Victorians have faster reactions?

#28
It's increasingly becoming clear that at least some part of the IQ is inheritable and that IQ has been falling for last 2 decades or longer as if the high IQ populace has lost their reproductive edge, probably artificially? Contraceptives are increasingly being used and women have the equal right so no one can force a woman to bear his child. Countries being analyzed have some form of welfare, so no one dies starving. Vaccines and expert help are easier to come by and the internet also helps here a lot. All this means, high IQ probably can help you earn millions but low IQ does not mean you die. Also, today high IQ populace is easier to discover, reward and keep busy with exciting work, so maybe they are no longer finding time to reproduce. And the ones who do not possess high IQ have plenty of time to have kids and take care of them. We've drastically changed the environment in which we live, so obviously, there will be some consequences. Then also our environment has evolved enough that we no longer need high IQ to survive.

Re: Did the Victorians have faster reactions?

#29
post #21

Earlier quoted context omitted.

> may have resulted from the presence of dysgenic fertility The effects might be interesting, but it seems like an entirely unsupported logical leap to attribute any effect to this cause.

Other way round : the author is a eugenicist looking for evidence. https://rationalwiki.org/wiki/Michael_A._Woodley_of_Menie

Rationalwiki isnt exactly an unbiased resource to put it lightly.
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