On correlation between the generation age of the fathers and grandfathers and the intelligence of the descendants.
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001722:Birth Order; D005190:Family; D005260:Female; D005823:Genetics; D006801:Humans; D007360:Intelligence; D008297:Male; D008875:Middle Aged; D010290:Parents; D012923:Social Class