INGROUP BIAS AND SELF-ESTEEM: A META ANALYSIS BY CHRISTOPHER L. ABERSON A Dissertation submitted to the Faculty of Claremont Graduate University in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Graduate Faculty of Psychology Claremont, California 1999 Approved by: ______________________________ Dr. Amy Marcus-Newhall © Copyright by Christopher L. Aberson, 1999 All Rights Reserved. We, the undersigned, certify that we have read this dissertation and approve it as adequate in scope and quality for the degree of Doctor of Philosophy. Dissertation Committee: ________________________________________________________________________ Dr. Amy Marcus-Newhall, Chair ________________________________________________________________________ Dr. Dale E. Berger, Member ________________________________________________________________________ Dr. Ximena B. Arriaga, Member ________________________________________________________________________ Dr. Michele A. Wittig, Visiting Examiner Abstract of the Dissertation Ingroup Bias and Self-Esteem: A Meta Analysis by Christopher L. Aberson Claremont Graduate University, 1999 Social Identity Theory contains two seemingly incompatible predictions regarding the relationship between self-esteem and ingroup bias. The first focuses on low self- esteem as motivation for bias, predicting that low self-esteem individuals exhibit more ingroup bias. The second posits that high self-esteem results from exhibiting bias, thus, high self-esteem individuals exhibit greater bias. A meta analysis examined the relationship between self-esteem and ingroup bias. Additionally, the project examined methodological issues such as the lack of consistency in measurement of self-esteem, artificial dichotomization of self-esteem scores, classification of individuals as low self-esteem, and theoretical considerations such as the use of different ingroup bias strategies and the role of social category salience. Thirty- four studies yielding 102 effect sizes from 6660 subjects were included in the analysis. Results indicated a consistent pattern whereby high self-esteem individuals exhibited more ingroup bias than did individuals with low self-esteem. However, this result was moderated by ingroup bias strategy. When using ingroup bias strategies that required ratings of ingroup superiority, high self-esteem individuals showed more ingroup bias than individuals with low self-esteem. However, when using "indirect" strategies, such as rating groups that the individual did not contribute to, differences between low and high self-esteem individuals were not found. This result leads to the conclusion that both groups exhibit ingroup bias; however, individuals with low self- esteem are limited in the types of bias they exhibit. The pattern of results held for all self-esteem measures except for the Collective Self-Esteem Scale (CSES). No differences between low and high self-esteem individuals were found when scores on the CSES defined self-esteem. These results may however be an artifact of interactions with social identity salience. Methodological shortcomings were found in the definition of low self-esteem. Individuals were most commonly classified as "low self-esteem" based on median splits of self-esteem scores. This strategy resulted in classification of some individuals as low self-esteem despite relatively high self-esteem scores. Results of the current analysis are interpreted as indicating that individual level phenomena such as self-esteem may be predictive of group level behaviors. Implications for social identity theories are discussed. Acknowledgments Many people deserve acknowledgment for their roles in the completion of this project. First, I would like to acknowledge my committee and the faculty who have provided invaluable assistance. I want to thank Amy Marcus-Newhall and Ximena Arriaga for their comments and more importantly, their generosity with their time. Michele Wittig deserves thanks for her continued support and for the assistance she has provided long after any official commitment to me or the university had ceased. Dale Berger deserves my heartfelt thanks for his friendship and mentoring. I cannot image having completed this project or the degree program without Dale. I will truly miss our regular meetings. Official thanks go to the Dora and Randolph Haynes Foundation for their financial support of this dissertation and to the Claremont Graduate University's Department of Psychology for Fellowship support. Also deserving of thanks are the individuals who provided information, encouragement, assistance, and, in some cases, data for the project at hand. Karen Long, Dominic Abrams, Miles Hewstone, Michael Hogg, Caroline Seta, and Sean McCrea all contributed in this manner. I commend each for their collegiality. My coders, Michael Healy and Victoria Romero deserve thanks for their diligent work for little pay. Of course, thanks go to my entire family. I specifically want to thank my Grandparents Ernest and Hedy Schlosser for supporting my graduate career and always being very proud of me. I have made several close friends during my stay at CGU. I want to thank Rob Short, Lisa Magaña, Eric Emerson, Susan Kelso, and Dave Nalbone for their love and vi support. The relationships I have developed in Claremont are something I hope to keep with me for the rest of my life. Finally, acknowledgments would not be complete without thanking Nanda Prato and the Prato family. Nanda has loved, supported, assisted, and tolerated me throughout this difficult process. vii TABLE OF CONTENTS INGROUP BIAS AND SELF-ESTEEM: A META ANALYSIS.......................................i CHRISTOPHER L. ABERSON...........................................................................................i Claremont, California...........................................................................................................i Abstract of the Dissertation................................................................................................iv Acknowledgments..............................................................................................................vi TABLE OF CONTENTS.................................................................................................viii TABLE OF FIGURES.......................................................................................................xv CHAPTER ONE: INTRODUCTION..................................................................................1 Figure 1. Corollary 1: High self-esteem results from ingroup bias.....................................2 The Role of Self-Esteem..................................................................................................4 Perspective One: Low Self-Esteem Leads to Greater Ingroup Bias................................6 Perspective Two: High Self-Esteem Leads to Greater Ingroup Bias...............................7 Critiques.........................................................................................................................10 Conclusion.....................................................................................................................20 The Current Project........................................................................................................20 Defining the Project.......................................................................................................21 CHAPTER TWO: METHODS..........................................................................................24 Overview........................................................................................................................24 Collection and Screening of Literature..........................................................................24 Coding of Study Characteristics....................................................................................29 Effect Size Derivation....................................................................................................32 viii Data Dependency Assumptions.....................................................................................37 Data Analysis Strategies................................................................................................39 Data Analysis (Testing Hypotheses)..............................................................................41 Adjusting for Low Reliability and Other Artifacts........................................................42 A Note on Effect Size Estimates....................................................................................45 CHAPTER THREE: RESULTS........................................................................................47 Descriptive Information.................................................................................................47 Definition of Low Self-Esteem..........................................................................................51 Ingroup Bias...................................................................................................................54 Analysis of Data and Tests of Hypotheses....................................................................56 Study Characteristics, Effect Sizes, and Confidence Limits..............................................57 Table 2 (Continued)...........................................................................................................61 Correlation Between Salience and Effect Size Within Cells and Overall.........................66