title: When does cognitive functioning peak? The asynchronous rise and fall of different cognitive abilities across the life span.
abstract: Understanding how and when cognitive change occurs over the life span is a prerequisite for understanding normal and abnormal development and aging. Most studies of cognitive change are constrained, however, in their ability to detect subtle, but theoretically informative life-span changes, as they rely on either comparing broad age groups or sparse sampling across the age range. Here, we present convergent evidence from 48,537 online participants and a comprehensive analysis of normative data from standardized IQ and memory tests. Our results reveal considerable heterogeneity in when cognitive abilities peak: Some abilities peak and begin to decline around high school graduation; some abilities plateau in early adulthood, beginning to decline in subjects' 30s; and still others do not peak until subjects reach their 40s or later. These findings motivate a nuanced theory of maturation and age-related decline, in which multiple, dissociable factors differentially affect different domains of cognition.
authors.affiliation: Department of Psychology, Harvard University jharts@mit.edu.
authors.forename: Joshua K
authors.initials: JK
authors.lastname: Hartshorne
authors.affiliation: Center for Human Genetic Research, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Laura T
authors.initials: LT
authors.lastname: Germine
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology* / Q000523:psychology; D003071:Cognition / Q000502:physiology*; D005260:Female; D006801:Humans; D007361:Intelligence Tests; D008297:Male; D008568:Memory; D008875:Middle Aged; D012307:Risk Factors; D055815:Young Adult
keywords: cognitive ability; cognitive development; individual differences; intelligence; language development