title: Genetic components and intellectual functioning during senescence: a 20-year study of aging twins.
mesh_terms: D000368:Aged; D000375:Aging; D001789:Blood Group Antigens; D003071:Cognition; D005260:Female; D005824:Genetics, Behavioral; D005838:Genotype; D006801:Humans; D007360:Intelligence; D007361:Intelligence Tests; D008297:Male; D008570:Memory, Short-Term; D008875:Middle Aged; D011247:Pregnancy; D014427:Twins
chemical_list: D001789:Blood Group Antigens