Ingroup versus outgroup choices of strategy made by boys playing a non-zero-sum game.
D000293:Adolescent; D001076:Aptitude; D002648:Child; D002653:Child Behavior Disorders; D003163:Competitive Behavior; D006126:Group Processes; D006801:Humans; D007398:Interpersonal Relations; D008297:Male; D009042:Motivation; D010551:Personality