title: Associations of job demands and intelligence with cognitive performance among men in late life.
abstract: OBJECTIVE
  To examine the association of job characteristics and intelligence to cognitive status in members of the National Academy of Sciences-National Research Council Twins Registry of World War II veterans.
  
  
  METHODS
  Participants (n = 1,036) included individuals with an assessment of intelligence based on Armed Services testing in early adulthood. In late adulthood, these individuals completed the modified Telephone Interview for Cognitive Status (TICS-m) and occupational history as part of an epidemiologic study of aging and dementia. Occupational history was coded to produce a matrix of job characteristics. Based on factor analysis, job characteristics were interpreted as reflecting general intellectual demands (GI), human interaction and communication (HC), physical activity (PA), and visual attention (VA).
  
  
  RESULTS
  Based on regression analysis of TICS-m score covarying for age, intelligence, and years of education, higher levels of GI and HC were independently associated with higher TICS-m performance, whereas higher PA was independently associated with lower performance. There was an interaction of GI and intelligence, indicating that individuals at the lower range of intellectual aptitude in early adulthood derived greater cognitive benefit from intellectually demanding work.
  
  
  CONCLUSIONS
  Intellectually demanding work was associated with greater benefit to cognitive performance in later life independent of related factors like education and intelligence. The fact that individuals with lower intellectual aptitude demonstrated a stronger positive association between work and higher cognitive performance during retirement suggests that behavior may enhance intellectual reserve, perhaps even years after peak intellectual activity.
authors: Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC 27701, USA. guy.potter@duke.edu
authors: Guy G
authors: GG
authors: Potter
authors: Michael J
authors: MJ
authors: Helms
authors: Brenda L
authors: BL
authors: Plassman
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology* / Q000523:psychology*; D002322:Career Mobility; D003071:Cognition / Q000502:physiology*; D003072:Cognition Disorders / Q000503:physiopathology / Q000517:prevention & control* / Q000523:psychology; D015331:Cohort Studies; D004522:Educational Status; D006801:Humans; D007360:Intelligence / Q000502:physiology*; D007361:Intelligence Tests; D007588:Job Satisfaction; D008297:Male; D013223:Statistics as Topic