“Reaction times and Intelligence Differences: A Population-Based Cohort Study”, 2001-09-01 (; backlinks; similar):
The association between reaction times and psychometric intelligence test scores is a major plank of the information-processing approach to mental ability differences. An important but unavailable datum is the effect size of the correlation in the normal population.
Here we describe the associations between scores on a test of general mental ability (Alice Heim 4, AH4) and reaction times using a ‘Hick’-style device. The sample is 900 people aged 56 years who are broadly representative of the Scottish population [West of Scotland 20–07 Study].
AH4 Part I total scores correlated −0.31 with simple reaction time, −0.49 with 4-choice reaction time, and −0.26 with intraindividual variability in both reaction time procedures. The correlation between AH4 scores and the difference between simple and 4-choice reaction time was −0.15. Separate analyses were conducted after partitioning the total group according to sex, educational level, social class grouping, and number of errors on the 4-choice reaction time task. None of these factors statistically-significantly altered the effect-sizes.
This is the first report of reaction time and psychometric intelligence in a large, normal sample of the population. It provides a benchmark for other studies and suggests larger effect sizes than the majority of present studies, which are dominated by young student samples.
[Keywords: intelligence, IQ, reaction time, information processing]