Investigating the effects of marijuana on human psychological functioning, this study differs from previous research in two ways: 1) it is concerned with relatively complex cognitive processes; 2) it has a theoretical rationale. The general hypothesis of the study states that marijuana will impair its user's ability to form and use abstract…

This study examines the relationship between development of a child's ability to coordinate perspective and his ability to conceptualize spatial relations on a map. One hundred and four school children from inner city, urban fringe, and suburban schools, grades K-6, were administered a Test of Coordination of Perspectives and a Test of Map…