title: A longitudinal study of problem solving in adults.
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging; D004522:Educational Status; D005500:Follow-Up Studies; D006040:Goals; D006801:Humans; D007361:Intelligence Tests; D008128:Logic; D008297:Male; D008875:Middle Aged; D011340:Problem Solving; D011594:Psychometrics; D013647:Task Performance and Analysis; D014825:Vocabulary