Porteus Maze Q score as a measure of impulsivity

The validity of the Q score (derived from the qualitative scoring of the Porteus Maze Test) as a measure of impulsivity was investigated by comparing the performance of high- and low-impulse groups. 80 Ss were employed and the Q score failed to differentiate high- from low-impulse institutionalized Ss, delinquent from nondelinquent Ss and extreme groups based on ratings. These findings are at variance with the claim that the Q score measures impulsivity.