By MICHAEL WOODLEY [Intelligence] – 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.

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The Victorian era was characterized by great accomplishments. As great accomplishment is generally a product of high intelligence, we tested the hypothesis that the Victorians were actually cleverer than modern populations. We used a robust elementary cognitive indicator of general intelligence, namely measures of simple RT. In the present study we used the data on the secular increase in simple RT described in a meta-analysis of 14 age-matched studies from Western countries conducted between 1884 and 2004 to generate estimates of the rate of IQ decline. The decline estimate of 1.23 IQ points per decade from the present study falls within the range of those produced in previous studies employing the magnitude of the dysgenic effect on IQ as the basis for estimating declines (i.e. .12 to approximately 1.3 points per decade). Our estimate is the first to be based on the use of real data rather than inference, however. Whilst the dysgenic model is a plausible cause of the decline in RT performance Silverman (2010) does not address this potential cause, and instead offers other suggestions.

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[W]hilst our value of a 14.1 IQ point decline is an estimate based on the best meta-analytical data available, a simple inspection of our figure shows there is a non-negligible amount of scatter around the regression line. The real magnitude of the effect might therefore be several IQ points lower or even higher. In conclusion however these findings do indicate that with respect to ‘genetic g’ the Victorians were indeed substantially cleverer than modern populations.

Full study at Intelligence via Scribd | A notice in the Daily Telegraph | See also Bruce Charlton’s Miscellany | More Chronicle & Notices.