Wednesday 19 March 2014

Further independent evidence on the slowing of simple reaction times (and therefore the decline of intelligence) over recent generations - using a new method


A first and preliminary sight of the data (in preparation for publication) showing a new and entirely different methodology for measuring the (probably dysgenic) decline in simple reaction times over recent generations - extrapolated to the past century. This confirms the result of the previous study.

Note added: I do not suppose the above independently-sourced evidence means that 'the case is closed' and the substantial decline in sRT/ Intelligence has been established beyond all reasonable doubt. All studies are flawed, none are conclusive. I do, however, believe that this confirmation means the earlier study of substantial Victorian-Modern sRT slowing cannot be dismissed - and the hypothesis of substantial RT slowing/ IQ decline must now be taken seriously by honest and competent people, and therefore ought to be followed-up by further testing and evaluation.



Adam G. said...


So if I follow, you used longitudinal reaction time data of the same people over the course of their lifetime to come up with a way of comparing reaction time data across different age groups. Which you want to do because comparing the reaction time data of contemporaries of different ages allows you to take snapshots of reaction time data from different generations. When you do that, you found that older generations had better reaction times, which has some correspondence with better general intelligence.

Bruce Charlton said...

@Adam - " When you do that, you found that older generations had better reaction times,"

Rather, the older generations had faster reaction times than would be predicted from the rate of age-related RT slowing.

Another way to think of this is that the authors of some (cross sectional) studies of sRT in people of different ages have expressed surprise at how little decline in reaction times occurs with age.

This would be explicable if the RT of older generations have indeed slowed considerably (as expected) - but beginning from a faster RT starting point when they were young.