Things are looking bad for the young challenger Woodley, who came out of the te Nijenhuis and Murphy corner swinging his punches against World Champion Jim Flynn, claiming that, on the basis of Galton’s reaction time data, the lower classes have been breeding too much, casting us all into dysgenic stupidity. His paper “Were the Victorians brighter than us?” (plugged on this blog) got lots of press coverage and, according to the editor, became one of the most downloaded papers on the Intelligence website. No sooner had he landed his eugenic blows on the chin of environmental optimism than there was a heavy weight, four round, concerted counter attack.
When the bell rang for the second round, back into the ring climbed the redoubtable Mighty Champion Flynn, a grizzled New Zealand pugilist, mentored by the great Jensen himself, veteran of many hard slogs, who leads with the left but can also jab with the right, but is always a principled follower of the Marquis of Queensbury’s rules. He hammered Woodley thus: Woodley’s estimated dysgenic rate is three times larger than the theoretical rate on the basis of the negative correlation between IQ and number of siblings throughout the 20th century, making Woodley’s finding implausible. Secondly the absence of a Jensen effect on the Flynn effect is not prima facie evidence that g has been in decline. Thirdly, the secular trend towards declining genius does not evidence the dysgenic trend owing to subjectivity amongst ratings of genius. Fourthly there is substantial methods variance, rendering cross-study comparisons difficult to say the least. Fifthly, despite the likely presence of dysgenic fertility in Australia during the period spanning 1981 to 2000, there is no decline in performance with respect to another elementary cognitive task (inspection time), which is problematic for the dysgenic interpretation of slowing reaction times.
Seeing the young challenger stunned by his solid punches, in a gracious concession just before the bell, Flynn did his own estimate of the dysgenic trend on Woodley’s data, admitting a smaller but evident 3 point decline overall.
For the third round the Australian Ted Nettlebeck, sun-bleached and hardened by the toil of 20 years of inspection time, jumped into the ring, to land these four Antipodean blows: Firstly, methods variance makes it difficult to compare studies. Secondly, the idea that antagonistic genetic and environmental forces can make intelligence trend in conflicting directions is flawed because the g loading of processing speed measures can only be established by correlating them with the same traditional measures of intelligence which show the Flynn effect. Thirdly, Nettlebeck argues that the decline in simple reaction times cannot constitute a decline in g because the principle causes are showing opposite secular gains. Fourthly, Nettelbeck also criticizes the assumption that simple RTs are associated with high heritability and that they are respectably g-loaded – arguing that both are required for the Woodley argument to work, but that neither is supported by the data.
For the fourth round, the experienced Silverman, a quieter fighter, with a good solid punch, and the original collector of historical reaction times enters the ring. These were his blows: the trend towards the secular lengthening of simple reaction times doesn’t hold when only the male cohorts are considered, in addition to the removal of the Galton datapoint. He contends that the presence of mixed-sex samples containing females (who have slower RT means than men on average) might have skewed the original Galtonian result. He adds that there are too few data points for Woodley to assume a linear relationship with slowing reaction time and year, which would be required to prove a dysgenic trend.
The fifth round brought in the formidable Russian Dodonov and Dodonova duo, an unusual husband and wife combination of legendary aggression, who think nothing of subjecting their own swaddling infant to a crash immersion in intelligence conferences, seeking precociously to add a third fighter to the team. As befits their energetic flurry of punches, they have even partly rebuilt Galton’s equipment to administer a final body blow: they contend that the studies lack comparability, and that controlling for this methods variance effectively obliterates the secular trend towards slowing RT speeds reported in both Silverman (2010) and Woodley et al. (2013). The error sources include stimulus onset delay, long and variable preparatory intervals and key pressure time, which inflate the latency of simple RT performance in more modern studies employing electronic rather than purely mechanical chronoscopes. Using a description of Galton’s pendulum chronoscope, they constructed a somewhat similar instrument, and found that the estimates produced are relatively free of sources of lag that seem to plague the more modern, electronic-instrument-based studies, such as key-pressure time. This is illustrated by direct comparison of the two author’s aggregate simple RT performance on both mechanical and electronic apparatuses – indicating a latency differential of approximately 30 ms favouring performance on the pendulum chronoscope in both cases. That puts puts the tin lid on it, surely? The pendulum method was faster than the contemporary electronic set up.
Te Nijenhuis and Murphy have been yelling encouragement, but the end of the fifth round the plucky Woodley is slumped on his corner stool, and there is only so much the duo can do with sticking plaster to repair their man’s battered countenance. Dutch pragmatism and Irish spirit have their limits. Quite frankly, Woodley’s choosing to box in his habitual long Edwardian jacket and gold pince-nez may not have been the best policy. Has it all been too much for him? Will he be able to stagger out for the sixth round?
The following paper has been submitted to Intelligence and is under review:
Woodley, te Nijenhuis, and Murphy “The Victorians were still quicker and cleverer than us: Responding to a quartet of critical commentaries.”
Whilst I cannot reveal the content until it has been accepted for publication, I can promise you horrific scenes of violence. If you are of nervous disposition, you should avert your eyes.