title: Smarter in middle age, faster in old age: a cross-lagged panel analysis of reaction time and cognitive ability over 13 years in the West of Scotland Twenty-07 Study.
abstract: Participants in the West of Scotland Twenty-07 Study performed reaction time tasks and took the Alice Heim 4 Part 1 test (AH4) of intelligence twice, 13 years apart. Cross-lagged associations between speed of processing and AH4 were examined using latent variables in structural equation modeling. The stability coefficients of the latent traits of processing speed and of AH4 score across 13 years were .49 and .89, respectively. There was a significant association (-.21) between AH4 score at age 56 and speed of processing at age 69 but not vice versa. The results fail to support the theory that processing speed is a foundation for successful cognitive aging but support a hypothesis that suggests that higher general intelligence might be associated with lifestyle and other factors that preserve processing speed.
authors.affiliation: Medical Research Council Centre for Cognitive Ageing and Cognitive Epidemiology, Department of Psychology, University of Edinburgh, Edinburgh, United Kingdom. I.Deary@ed.ac.uk
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Deary
authors.forename: Michael
authors.initials: M
authors.lastname: Allerhand
authors.forename: Geoff
authors.initials: G
authors.lastname: Der
mesh_terms: D000368:Aged; D000375:Aging / Q000523:psychology*; D001076:Aptitude; D002755:Choice Behavior; D005260:Female; D006306:Health Surveys; D006801:Humans; D007361:Intelligence Tests / Q000706:statistics & numerical data*; D008019:Life Style; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D011930:Reaction Time; D012923:Social Class