Throughout their paper the authors argue that higher intelligence of persons alive during the Victorian era can explain why their creativity and achievements were markedly greater than for later, duller generations. We can leave aside an important question whether there is any sound evidence that creativity and intellectual achievements have declined since a Great Victorian Flowering because only two of the 16 datasets they compared were collected before Victoria’s death in 1901. The remaining 14 datasets date between 1941 and 2004 and, of these, only four were collected before 1970. So most of the studies analysed were made within my personal working lifespan. This provokes both nostalgia and distrust. Between 1959 and 2004 I collected reaction times (RTs) from many large samples of people but it would make no sense for me to compare absolute values of group mean RTs that I obtained before and after 1975. This was because, until 1975, like nearly all of my colleagues, the only apparatus I had were Dekatron counters, the Birren Psychomet or SPARTA apparatus, none of which measured intervals shorter than 100 msec. Consequently, when my apparatus gave a reading of 200 msec. the actual Reaction Time might be anywhere between 200 and 299 msec. Like most of my colleagues I always computed and published mean RTs to three decimal places, but this was pretentious because all the RTs I had collected had been, in effect, rounded down by my equipment. After 1975, easier access to computers and better programs gradually began to allow true millisecond resolution. More investigators took advantage of new equipment and our reports of millisecond averages became less misleading. I am unsurprised that mean RTs computed from post-1975 data were consistently, and significantly longer than those for pre-1975 data.
Changes in recording accuracy are a sufficient reason to withold excitement at Woodley et al’s comparison. It is worth noticing that different methodological issues also make it tricky to compare absolute values for means of RTs that were collected at different times and so with different kinds of equipment. For example RTs are affected by differences in signal visibility and rise-times to maximum brightness between tungsten lamps, computer monitor displays, neon bulbs and LCDs. The stiffness and “throw” of response buttons will also have varied between the set-ups that investigators used. When comparing absolute values of SRTs, another important factor is whether or not each signal to respond is preceded by a warning signal, whether the periods between warning signals and response signals are constant or variable and just how long they are (intervals between, approximately, 200 and 800 ms allow faster RTs than shorter or longer ones) Knowing these methodological quirks makes us realise that, in marked contrast to intelligence tests, methodologies for measuring RT have been thoroughly explored but never standardised.
So I do not yet believe that Wooley et al’s analyses show that psychologists of my generation were probably (once!) smarter than our young colleagues (now) are. This seems unlikely, but perhaps if I read further publications by these industrious investigators I may become convinced that this is really the case.
Flynn, J. R. (1987). Massive IQ gains in 14 nations - what IQ tests really measure. Psychological Bulletin, 101(2), 171-191. doi: 10.1037/0033-2909.101.2.171
Michael A. Woodley, Jan te Nijenhuis, & Raegan Murphy (2013). Were the Victorians cleverer than us? The decline in general intelligence estimated from a meta-analysis of the slowing of simple reaction time Intelligence : http://dx.doi.org/10.1016/j.intell.2013.04.006