or so woodley, te nijenhuisc, and murphy have concluded:
– Simple reaction time has slowed since 1889.
– Simple reaction time genetically correlates with g.
– Psychometric meta-analysis reveals a decline in g of − 1.23 points per decade.
– The decline between 1889 and 2004 is − 14.1 points.
– This is the first direct measurement of a probable dysgenic trend in IQ.
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, starting in the 19th century, suggests that these trends might be related to declining IQ. This is because high-IQ people are more productive and more creative. We tested the hypothesis that the Victorians were cleverer than modern populations, using high-quality instruments, namely measures of simple visual reaction time in a meta-analytic study. Simple reaction time measures correlate substantially with measures of general intelligence (g) and are considered elementary measures of cognition. In this study we used the data on the secular slowing of simple reaction time described in a meta-analysis of 14 age-matched studies from Western countries conducted between 1884 and 2004 to estimate the decline in g that may have resulted from the presence of dysgenic fertility. Using psychometric meta-analysis we computed the true correlation between simple reaction time and g, yielding a decline of − 1.23 IQ points per decade or fourteen IQ points since Victorian times. These findings strongly indicate that with respect to g the Victorians were substantially cleverer than modern Western populations.
my first question, of course, would be: are they comparing like with like? the authors write:
“We take our general inclusion rules from the meta-analysis by Silverman (2010)…. Third, given that Galton’s sample was British the studies had to have been conducted in a Western country.”
ehhhh. but the demographics of western nations — especially the u.s. and the u.k. — have changed a lot from victorian days!
i especially started asking myself if they’ve compared like with like when i noticed in their table that the iqs of the finnish in the 1980s-90s — demographically still very much a white northern european in those decades — were pretty much the same as the victorians’ scores:
the two reaction time studies on the victorians were done by galton in the u.k. in 1884-1893 and someone named h.b. thompson in the u.s. in 1898-1900. galton’s study presumably included mostly white britons and perhaps some amount of ashkenazi jews. thompson’s study, which was conducted on university of chicago students, was almost certainly comprised of mostly white americans.
what about all the later studies? well, i don’t have access to most of them, but here’s what i found out about a couple of them (again see the table above):
– the 2002 study from the u.k. (rt=324): Effects of caffeine on mood and performance: a study of realistic consumption [pdf] – the subjects were 24 university of bristol students. now, in 2002 at least 10.5% of the university of bristol student population were non-whites, possibly more since the ethnicities of 17.8% of the student population were unknown. this is not really comparing like with like when at least 1 in 10 of the subjects was not white, unlike in galton’s or thompson’s studies. and, do we even know what the ethnic/racial backgrounds of the subjects in this study were? nope.
– the 1984–85 from the u.k. (rt=300): Age and Sex Differences in Reaction Time in Adulthood: Results From the United Kingdom Health and Lifestyle Survey [pdf] – the subjects in this study were drawn from the 1984-85 health and lifestyles survey. i don’t know for sure, but presumably this was meant to be a representative survey — representative of the population of the u.k. in the early 1980s, minorities were 4.2% of the u.k. population [pdf], so 4 out of every 100. and what about the presence of, say, southern europeans in the u.k. at the time? i have no idea, but clearly these things should be taken into account.
i dunno. this is a really neat study, and maybe woodley, et al., are on to something, but i’d like some reassurance that they’re looking at the same sorts of populations.
– Objective and direct evidence of ‘dysgenic’ decline in genetic ‘g’ (IQ) and Taking on-board that the Victorians were more intelligent than us and Intelligence declined one SD since Victorian times – why NOT? from bruce charlton!
– The Victorians were cleverer than us! and ORIGINAL PAPER: “A response to Prof Rabbitt – The Victorians were still cleverer than us” by Woodley, te Nijenhuis and Murphy and Can I have a reaction? @dr. james thompson’s blog!
edit: see also btw, about those victorians…
(note: comments do not require an email. sir francis galton.)