title: Paternal age in relation to offspring intelligence in the West of Scotland Twenty-07 prospective cohort study.
abstract: BACKGROUND
  The adverse effects of advancing maternal age on offspring's health and development are well understood. Much less is known about the impact of paternal age.
  
  
  METHODS
  We explored paternal age-offspring cognition associations in 772 participants from the West of Scotland Twenty-07 study. Offspring cognitive ability was assessed using Part 1 of the Alice Heim 4 (AH4) test of General Intelligence and by reaction time (RT).
  
  
  RESULTS
  There was no evidence of a parental age association with offspring RT. However, we observed an inverse U-shaped association between paternal age and offspring AH4 score with the lowest scores observed for the youngest and oldest fathers. Adjustment for parental education and socioeconomic status somewhat attenuated this association. Adjustment for number of, particularly older, siblings further reduced the scores of children of younger fathers and appeared to account for the lower offspring scores in the oldest paternal age group.
  
  
  CONCLUSIONS
  We observed a paternal age association with AH4 but not RT, a measure of cognition largely independent of social and educational experiences. Factors such as parental education, socioeconomic status and number of, particularly older, siblings may play an important role in accounting for paternal age-AH4 associations. Future studies should include parental intelligence.
authors.affiliation: MRC/CSO Social and Public Health Service Unit, Glasgow, United Kingdom. elise.whitley@bristol.ac.uk
authors.forename: Elise
authors.initials: E
authors.lastname: Whitley
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Deary
authors.forename: Geoff
authors.initials: G
authors.lastname: Der
authors.forename: G David
authors.initials: GD
authors.lastname: Batty
authors.forename: Michaela
authors.initials: M
authors.lastname: Benzeval
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D007360:Intelligence; D008297:Male; D008423:Maternal Age; D008875:Middle Aged; D010331:Paternal Age; D011446:Prospective Studies; D011581:Psychological Tests; D011930:Reaction Time; D012606:Scotland; D035781:Siblings; D055815:Young Adult