Contribution of age, genes, and environment to the relationship between perceptual speed and cognitive ability.
The aim of this study was to examine genetic influences on cognitive ability in adulthood in the context of the relationship between perceptual speed and cognitive aging. Quantitative genetic analysis of data from the Swedish Adoption/Twin Study of Aging allowed for estimation of the contribution of age, genetic, and environmental effects to the variance in a latent cognitive factor and to the covariance between the cognitive factor and perceptual speed. The sample included 292 pairs of monozygotic and dizygotic twins. both reared together and reared apart, ranging in age from 40 to 84 years. Analysis of components of total variance in the cognitive factor indicated that 90% of the age-related variance in the cognitive factor was shared with perceptual speed and 70% of the genetic variance in the cognitive factor was shared with perceptual speed. The correlation between the speed and cognitive factors was primarily genetically mediated.
Finkel
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Division of Social Sciences, Indiana University Southeast, New Albany 47150, USA. dfinkel@ius.edu
Pedersen
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NL
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000235:genetics / Q000502:physiology / Q000523:psychology*; D000704:Analysis of Variance; D003071:Cognition / Q000502:physiology; D005260:Female; D005823:Genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D008957:Models, Genetic; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D010465:Perception; D012931:Social Environment; D014429:Twins, Dizygotic / Q000235:genetics; D014430:Twins, Monozygotic / Q000235:genetics; D014888:Wechsler Scales / Q000706:statistics & numerical data