The 16 Personality Factors Questionnaire (16 PF), Motivation Analysis Test (MAT), and a marihuana usage questionnaire were administered anonymously to 104 undergraduate students. Raw scores were converted to sten scores to eliminate sex and age differences. Product-moment correlations were computed on data from the questionnaires. An iterative principal axis solution was applied to the correlation matrix followed by Kaiser Varimax orthogonal rotation and graphical oblique rotations.

The most significant finding was that marihuana users were not a homogeneous group in terms of personality and motivational structure. Four identifiable personality and motivational patterns were found to be related to such use: (a) an antisocial norm group; (b) a frustrated upper-middle class group; (c) a hostile rebel group; (d) a follower group. None of these indicate pathological patterns.