Master's Theses



Degree Name

Master of Science (MS)


The purpose of this investigation was to assess the ability of the Psychopathy Checklist (PCL) to differentiate between psychopaths (as defined by Cleckley & Hare) and non-psychopaths in a criminal population. In addition, this investigation assessed the ability of the Tiffany Control Scales (TCS) and Rotter's Internal/ External Scale to measure the level of control that exists among psychopaths. The PCL measures both personality-related and behavior-related characteristics of psychopathy; it can be used to obtain both dimensional and categorical scores, it is scored on the basis of both present-state and historical information; and the target population--criminals--is a group for whom there is always collateral information available. The PCL is a 20-item scale scored from interview and file information. Each of the 20 items obtained from the interview was scored on a 3-point ordinal scale with a score of 30 or more indicating psychopathy. The Tiffany Control Scales (TCS) is a 32-item personality inventory that assesses perceived control over and perceived control from events and influences in eight common life situations. The participant responses were recorded on a scale ranging from a (no control) to 100 (complete control). Rotter's I-E Scale is a 29-item questionnaire designed to assess whether an individual perceives their generalized experiences as being determined by internal control versus external control. The psychopathy mean score (0 to 40) for the 34 subjects was 29.5. These figures indicate that the majority of subjects were classified as psychopathic. The overall mean obtained on Rotter's I-E scale was 7.235 out of a total of 23 external choice items indicating that these individuals are likely to have more internal than external expectancies. Of the four component factors (Fl, OI, OE, FE) on the TCS, none were revealed as being statistically different in terms of comparing the prisoners with the Tiffany standardized sample . This suggests that these prisoners exhibit a level of control similar to Tiffany's standardized sample. When conducting a Pearson Correlation among the PCL and Rotter's I-E scale, no significant relationship was found (r = -.1175; p < .05). The only significant relationship that did exist was between the PCL and the TCS component factor FI (r = .4156; p < .05). Data analysis did reveal other significant findings relevant to this study as discussed in the text.


Phyllis G. Tiffany

Date of Award

Spring 1991

Document Type

Thesis - campus only access


© 1991 Dawn L. Nelson


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