A thesis submitted to the Faculty of Graduate Studies
in partial fulfilment of the requirements
for the degree of

Doctor of Philosophy

Graduate Program in Administrative Studies
York University
Toronto, Ontario

April 12, 2001

Permission has been granted to the LIBRARY OF YORK UNIVERSITY to lend or sell copies of this dissertation, to the NATIONAL LIBRARY OF CANADA to microfilm this dissertation and to lend or sell copies of the film, and to UNIVERSITY MICROFILMS to publish an abstract of this dissertation. The author reserves other publication rights, and neither the dissertation nor extensive abstracts from it may be printed or otherwise reproduced without the author's written permission.


Although practitioners insist that humor is effective as an aid to persuasion, previous research has produced conflicting and inconclusive results. The thesis of this dissertation is that humor's effectiveness can be demonstrated only if it is first explained theoretically. After reviewing both humor theory and persuasion theory, specific propositions were made about when humor would be effective in persuasion. It was predicted that cartoon drawings would increase susceptibility to persuasion by generating an agreeable mood, that ironic comments would increase susceptibility to persuasion by providing a cognitive distraction, and that self-effacing humor would increase susceptibility to persuasion by increasing liking for the source.

The Ethics Challenge was selected as an example of the use of humor in persuasion. It is a board game that uses cartoon characters and wisecracks to persuade Lockheed Martin employees to consult the ethics office when in doubt. Participants were 170 adults studying business at a large public university. The dependent variable was persuasion, measured with six behavioral intention items and five descriptive-adjective ratings. In a controlled experiment, elements of the humor were removed from the game. Whenever this inhibited the effectiveness of the Ethics Challenge, it was inferred that the element had been playing an important role.

Overall, the use of humor had a weak but significant impact on persuasiveness. Cartoon drawings alone generated negligible effects. Self-effacing humor improved the effectiveness of the message, seemingly by increasing source credibility. Ironic wisecracks improved the effectiveness of the message even more. Further research into the causal mechanisms that explain these results is advocated, and a campaign of re-education is recommended to generate realistic expectations for the benefits of humor in the workplace.


Gary David (Tomlinson) passed away July 18, 1996, just as I was entering this program. I met him when I was a musician with entertainer Johnnie Johnston. Gary used our audiences to refine the comedy act that would later make him a headliner at Mark Breslin's chain of Yuk Yuk's comedy cabarets. Gary understood the value of humor; he found success late in life and shared it generously with everyone he knew.

I grew up watching comedians who understood pathos as well as sarcasm, such as Johnny Carson, Carol Burnett, and Red Skelton (who passed away September 17, 1997, as I began my second year). My parents taught me that humor was important and serious, and that humorists performed a noble function. My mother contributed an artistic side that enabled me to have an early career as a musician. My father contributed an analytical side that enabled me to tackle this academic project.

This work is dedicated to all of those wonderful people.


For some reason I have always been blessed with understanding friends, sympathetic lovers, and incredibly patient bosses.

This dissertation would not have been possible without the assistance of several people who are mentioned here in roughly chronological order. Christine Oliver headed up the committee that admitted me and, later, my Comprehensive Examination Committee. Gareth Morgan encouraged me to stand up for my own ideas. Rekha Karambayya encouraged me to take humor seriously and responsibly as an academic pursuit. David Dimick offered sage advice from the beginning and Rob Lucas refused to let me get away with less than thoughtful work. Thank you, all.

Ron Burke has been my supervisor, patient listener, advisor, mentor (occasional tormentor), and friend. Thanks for setting a terrific example of a teacher/scholar.

© 2001, James Bruce Lyttle