Psychology Ph.D. Dissertations


Modification of Weight Bias: Examining the Effects of Social Influence on the Expession of Anti-Fat Attitudes

Date of Award


Document Type


Degree Name

Doctor of Philosophy (Ph.D.)



First Advisor

Robert Carels, Ph.D.

Second Advisor

Catherine Stein, Ph.D. (Committee Member)

Third Advisor

Dara Musher-Eizenman, Ph.D.

Fourth Advisor

Lynn Darby, Ph.D.


Widespread implicit and explicit bias and discrimination based on weight have been documented in many key areas of life. The objective of this study was to test the effects of different types of influences on the expression of stereotypes towards people who are obese. Participants included 158 undergraduate students who were randomly assigned to one of four conditions. In three conditions (fourth was a control), participants completed measures of attitudes towards people who are obese prior to and after receiving manipulated feedback depicting attitudes of others (anonymously or non-anonymously) or scientific information about the base rates of these traits in the obese population. This study compared bias levels between a non-anonymous (Public Feedback) and anonymous feedback conditions. It also compared participants attitude change in the social feedback conditions with a trait prevalence feedback condition. These changes were examined for both explicit and implicit attitudes and participants motivations for potential attitude change were also assessed. Results indicated that explicit beliefs are influenced more when people perceive that others views are inconsistent with their own in a non-anonymous setting than an anonymous one. Trait prevalence information was less effective than non-anonymous feedback but more effective than the anonymous condition in reducing negative biases. Implicit anti-fat biases were quite evident and more resistant to change than explicit beliefs. Thus, people are sensitive to the views of others when expressing opinions about groups of others, especially when this expression occurs in a public setting. Perceived opinions of others may slightly influence internal, automatic reactions to people who are obese as well.