Testing Public Anxiety Treatments Against a Credible Placebo Control

Abstract

Research investigating public speaking anxiety treatments is subject to demand effects. This study tests the relative effectiveness of systematic desensitization (SD) and multiple treatment method (MT) containing visualization therapy against no-treatment and credible placebo controls. Data (n=238) were collected at six points in a public speaking class. Reported anxiety decreased over time, but neither treatment outperformed the placebo control. Short-term gains were apparent for the MT group with participants selected on the basis of extreme high scores, but these gains did not persist relative to the control conditions over time. The current data suggest no evidence of lasting improvement of SD or MT treatments over a credible placebo control and enrollment in a standard public speaking class.

Keywords:

• Communication Apprehension
• Systematic Desensitization
• Placebo
• Public Speaking

Notes

1. The distribution of conditions across course sections and instructors were checked for uneven distributions, and the distributions did not depart from chance for either sections, χ² (27, N=238) = 20.75, p=.80 or instructors, χ² (18, N=238) = 9.16, p=.96. Further, all post treatment scores were checked for section or instructor effects. No significant intra-class correlations were found, and the largest was ρ=.06.

2. Thom Jayne granted permission for the use of his music. To hear a sample of his music, one can visit the website at http://cdbaby.com/cd/thomjayne

3. Although treatment credibility was not scaled (to avoid further demand effects), informal observations suggest that students found it highly credible. A number of students told the experimenter that they found procedures believable, and others expressed concerns about possible side effects.

4. The tape was procured from Dr. James C. McCroskey, Department of Communication Studies, University of Alabama at Birmingham. It is currently available through the National Communication Association.

Additional information

Notes on contributors

Desiree C. Duff

Desiree C. Duff (M.A., Purdue University, 1982) is a doctoral candidate, Department of Communication, Michigan State University and Assistant Professor, Cornerstone University

Timothy R. Levine

Timothy R. Levine (Ph.D., Michigan State University, 1992) is Professor of Communication, Michigan State University

Michael J. Beatty

Michael J. Beatty (Ph.D., Ohio State University, 1976) is Professor of Communication, University of Missouri-St. Louis

Jessica Woolbright

Jessica Woolbright received her B.A. from Cornerstone University, 2005

Hee Sun Park

Hee Sun Park (Ph.D., University of California at Santa Barbara, 2003) is Assistant Professor of Communication, Michigan State University