Justice Thurgood Marshall proposed a three-pronged postulate in his dissent in1972 in the Furman v. Georgia (408 U.S. 238) Supreme Court case. The American public is generally uninformed when it comes to the death penalty, and given information a "great mass of citizens" would be against it, unless their underlying beliefs were rootedin retribution (Furman v. Georgia, p. 363). These statements subsequently came to be known as the Marshall Hypothesis, and were deemed testable by researchers. This study examines the influence on death penalty opinion as a consequence of participating in a college class on the death penalty. Students in the class, who were either criminology majors or minors, were asked to take part in a questionnaire regarding their attitudes toward capital punishment at the beginning and at the end of the semester.Over the course of the class, students took part in a pre and post-test designed to measure their knowledge of the death penalty. This study correlated the amount of knowledge gained by each student with their respective death penalty attitudes. Results indicated that many in the class had little knowledge of the practice, application, and corollary effects of capital punishment. Those students who made the greatest amount of knowledge gains also reported a reduction in support for capital punishment. The acceptance of death penalty truths was not found to be related to a reduction in death penalty support. Further analysis, however, showed that those students who accepted these death penalty “truths” were also able to disregard death penalty “myths.” The present study concludes that support for the death penalty is directly reduced through increased knowledge gain, and indirectly reduced through truth acceptance as a function of death penalty “myth” abandonment.

This thesis tests the three hypotheses derived from the written opinion of Justice Thurgood Marshall in Furman v Georgia in 1972. Subjects completed questionnaires at the beginning and the end of the fall 2006 semester. Experimental group subjects were enrolled in a death penalty class, while control group subjects were enrolled in another criminal justice class. The death penalty class was the experimental stimulus. Findings provided strong support for the first and third hypotheses, i.e., subjects were generally lacking in death penalty knowledge before the experimental stimulus, and death penalty proponents who scored "high" on a retribution index did not change their death penalty opinions despite exposure to death penalty knowledge. Marshall's second hypothesis--that death penalty knowledge and death penalty support were inversely related--was not supported by the data. Two serendipitous findings were that death penalty proponents who scored "low" on a retribution index also did not change their death penalty opinions after becoming more informed about the subject, and that death penalty knowledge did not alter subjects' initial retributive positions. Suggestions for future research are provided.