University of Windsor Scholarship at UWindsor Electronic Theses and Dissertations 2011 The Language-Aggression Hypothesis in Preschoolers: Maternal Scaffolding and Self- Regulation Robert Clark University of Windsor Follow this and additional works at:http://scholar.uwindsor.ca/etd Recommended Citation Clark, Robert, "The Language-Aggression Hypothesis in Preschoolers: Maternal Scaffolding and Self-Regulation" (2011).Electronic Theses and Dissertations.Paper 495. This online database contains the full-text of PhD dissertations and Masters’ theses of University of Windsor students from 1954 forward. These documents are made available for personal study and research purposes only, in accordance with the Canadian Copyright Act and the Creative Commons license—CC BY-NC-ND (Attribution, Non-Commercial, No Derivative Works). Under this license, works must always be attributed to the copyright holder (original author), cannot be used for any commercial purposes, and may not be altered. Any other use would require the permission of the copyright holder. Students may inquire about withdrawing their dissertation and/or thesis from this database. For additional inquiries, please contact the repository administrator via email ([email protected]) or by telephone at 519-253-3000ext. 3208. THE LANGUAGE-AGGRESSION HYPOTHESIS IN PRESCHOOLERS: MATERNAL SCAFFOLDING AND SELF-REGULATION by Robert Clark A Dissertation Submitted to the Faculty of Graduate Studies through the Department of Psychology in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy at the University of Windsor Windsor, Ontario, Canada 2011 © 2011 Robert Clark The Language-Aggression Hypothesis In Preschoolers: Maternal Scaffolding and Self- Regulation by Robert Clark APPROVED BY: __________________________________________________ Dr. M. Beeghly, External Examiner Wayne State University _________________________________________________ Dr. K. Gorey Department of Social Work __________________________________________________ Dr. D. Jackson Department of Psychology ________________________________________________ Dr. J. Hakim-Larson Department of Psychology __________________________________________________ Dr. R. Menna, Advisor Department of Psychology __________________________________________________ Dr. J. Ku, Chair of Defense Faculty of Graduate Studies May 19, 2011 iii AUTHOR’S DECLARATION OF ORIGINALITY I hereby certify that I am the sole author of this thesis and that no part of this thesis has been published or submitted for publication. I certify that, to the best of my knowledge, my thesis does not infringe upon anyone’s copyright nor violate any proprietary rights and that any ideas, techniques, quotations, or any other material from the work of other people included in my thesis, published or otherwise, are fully acknowledged in accordance with the standard referencing practices. Furthermore, to the extent that I have included copyrighted material that surpasses the bounds of fair dealing within the meaning of the Canada Copyright Act, I certify that I have obtained a written permission from the copyright owner(s) to include such material(s) in my thesis and have included copies of such copyright clearances to my appendix. I declare that this is a true copy of my thesis, including any final revisions, as approved by my thesis committee and the Graduate Studies office, and that this thesis has not been submitted for a higher degree to any other University or Institution. iv ABSTRACT In light of recent findings suggesting that physical aggression peaks during the toddler years then declines steadily beginning in preschool (e.g., Alink et al., 2006; Tremblay et al., 2004), greater emphasis has been placed on identifying early factors that might predispose children to disruptive behaviour problems as they mature. The present study investigated the effects of early language development, executive functioning, and maternal scaffolding on physically aggressive behaviour among a sample of preschool- aged children (N = 126). In step one, regression analyses revealed various preschooler language abilities negatively predicted physical aggression after controlling for potential confounding variables (e.g., children’s IQ, family structure, socioeconomic status, maternal education). The second set of analyses showed preschoolers’ executive functions (i.e., inhibitory self-control, emergent metacognition) mediated the relation between their language abilities and physical aggression. Maternal scaffolding was introduced in the third step of analyses and was found to predict preschoolers’ semantic language abilities. After separating the sample on the basis of scaffolding quality, differences were found in terms of the specific executive functions that mediated the language-aggression relation between groups. The results are interpreted from a developmental perspective, with reference to the work of Vygotsky (1962, 1978). The implications of these findings for early intervention of disruptive behaviour problems are also discussed and recommendations are made for future research in the area of self- regulation. v DEDICATION For my wife Heather to whom I will always be grateful for reminding me that life is far bigger than any one pursuit. vi ACKNOWLEDGEMENTS There are a number of people without whom this project would not be possible. First and foremost, I would like to thank the many families who volunteered their time, as well as the community agencies and services that supported the study. Also worthy of acknowledgement are the many research assistants who helped with the study and without whom the study would not have run so efficiently. A special thanks goes to my research colleagues, Holly Ambrose, Sara O’Neil, and Adam Kayfitz who lived and breathed the project along with me, but more importantly, helped make if a very meaningful experience. My genuine appreciation also goes to my committee members (Dr. Julie Hakim-Larson, Dr. Dennis Jackson, Dr. Kevin Gorey, and Dr. Marjorie Beeghly) whose insights and suggestions were invaluable. Finally, I liked to express my sincerest gratitude to Dr. Rosanne Menna who first piqued my interest in child development as an undergraduate student, and has patiently “scaffolded” my research endeavours ever since. Her trusted guidance and expertise has helped make this process truly rewarding. vii TABLE OF CONTENTS AUTHOR’S DECLARATION OF ORIGINALITY iii ABSTRACT iv DEDICATION v ACKNOWLEDGEMENTS vi LIST OF TABLES viii LIST OF FIGURES x I. INTRODUCTION 1 General Context and Objectives of the Present Study 1 II. REVIEW OF THE LITERATURE 9 The Problem of Childhood Aggression 9 The Relation between Physical Aggression and Language Development 14 Physical Aggression and Language Delay: The Self-Regulation Pathway 29 Historical Views on the Development of Self-Regulation 32 Contemporary Views on the Development of Self-Regulation 38 Language, Self-Regulation, and Physical Aggression in Early Childhood 47 Parental Socialization of Children’s Self-Regulation 63 Summary of the Problems and Objectives of the Present Study 86 III. METHODOLOGY 91 Participants 91 Recruitment and Procedure 95 Measures 99 IV. RESULTS 115 Planned Analyses 115 Data Screening and Preparation 116 Main Analyses: Examination of the Direct Effects Model 123 Main Analyses: Examination of the Mediation Model 128 Main Analyses: The Effects of Scaffolding on the Mediation Model 150 Summary 161 V. DISCUSSION 164 Step One: The Language-Aggression Hypothesis 164 Step Two: The Mediation Model 167 Step Three: The Self-Regulation Pathway as a Function of Maternal Scaffolding 175 Clinical Implications 180 Limitations of the Present Study 183 Future Directions 186 REFERENCES 189 APPENDIX A 221 APPENDIX B 227 APPENDIX C 237 VITA AUCTORIS 239 viii LIST OF TABLES Table 1. Demographic Characteristics 93 Table 2. Inter-rater Agreement Statistics for Coding of Maternal Scaffolding 114 Table 3. Descriptive Statistics for Study Variables before Transformations 117 Table 4. Descriptive Statistics for Study Variables following Transformations 120 Table 5. Correlations between Study Variables and Demographic Variables 122 Table 6. Correlations between Study Variables before Transformations 124 Table 7. Correlations between Study Variables following Transformations 125 Table 8. Summary of the Standard Multiple Regression Analyses for the Prediction of Physical Aggression - Transformed from Language Domains 127 Table 9. Summary of the Standard Multiple Regression Analyses for the Prediction of Executive Functioning from Receptive Language – Transformed 131 Table 10. Summary of the Standard Multiple Regression Analyses for the Prediction of Executive Functioning from Expressive Language 133 Table 11. Summary of the Standard Multiple Regression Analyses for the Prediction of Executive Functioning from Semantic Language 134 Table 12. Summary of the Standard Multiple Regression Analyses for the Prediction of Executive Functioning from Semantic Language 136 Table 13. Summary of the Standard Multiple Regression Analyses for the Prediction of Physical Aggression – Transformed from Executive Functioning 139 Table 14. Bias Corrected and Accelerated Confidence Intervals for the Mediation Effect of Inhibitory Self-Control – Transformed on the Relation between Receptive Language – Transformed and Physical Aggression - Transformed 144 ix Table 15. Bias Corrected and Accelerated Confidence Intervals for the Mediation Effect of Inhibitory Self-Control on the Relation between Expressive Language and Physical Aggression – Transformed 147 Table 16. Summary of the Standard Multiple Regression Analyses for the Prediction of Preschoolers’ Language Abilities from Maternal Scaffolding 152 Table 17. Correlations between Study Variables for High Scaffolding Group 154 Table 18. Correlations between Study Variables for Low Scaffolding Group 158 Table 19. Summary of Standard Multiple Regression Analyses for Low Scaffolding Mother-Child Pairs 159