Expectancy, demand characteristics, and contact desensitization in behavior change

Contact desensitization, attention placebo, and instructions to simulate the effects of attention placebo were compared in their ability to alleviate fears of rats in college students under brief group therapy conditions. The results were: (a) contact desensitization was highly effective and superior to the groups controlling for expectancy and demand characteristics and to a no-treatment control group; (b) although not performing as well as Ss receiving contact desensitization, role playing Ss effectively simulated improvement on the behavioral approach test; and (c) the expectancy manipulation did not result in significant improvement.