COUPLE OUTCOMES IN STEPFAMILIES Vanessa Leigh Bruce B. Arts, B. Psy (Hons) This thesis is submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Clinical Psychology, School of Psychology, Faculty of Health, Griffith University, Brisbane. December, 2010.
Declaration I hereby declare that this thesis is my own original work, and that to the best of my knowledge, it contains no material previously published or written by another person without due reference in the text. I also declare that no work presented in this text has been presented for the award of another degree or diploma at a university or other institute of higher learning. Data collection was conducted by myself. My original input is as follows: 1. I conducted the literature review; designed the research hypotheses; and collated the assessment materials. 2. I actively participated in the collection, scoring and computer entry of the data for the final wave of data collection of both studies reported. 3. I conducted all data analyses and have produced all the written output. Data collection was conducted with the approval of the Griffith University Ethics Committee. The original data is archived and available for inspection. Vanessa Bruce December, 2010 ii
Acknowledgements I wish to acknowledge the support, expertise and generosity of time provided by my supervisors Professor Kim Halford and Dr Liz Jones. I have greatly appreciated their in-depth feedback and much needed pushing and prodding along the way. A special thank you to Professor Kim Halford who has been supportive in what has been a difficult process at times and I couldn t have done this without his endless patience and encouragement. I also wish to thank Maddy Phillips and Lisa Babon for their hard work and contribution to this study and express gratitude to all the families who participated in this research. Further appreciation is expressed to my family for their constant encouragement and understanding throughout the years. A big thank you also, to fellow student, Dr Nadine Smith, for her guidance and amazing friendship which helped to keep me sane throughout the PhD journey. Finally, but perhaps most importantly, I extend my sincere thanks to my husband Tim, for his incredible support and for always believing in me. iii
Abstract Stepfamilies are an increasingly common family structure which has been associated with unique challenges for couples early in their relationships. Previous research has shown that both children and couples within stepfamilies have poorer outcomes than those in first marriage (intact) families and that couples within stepfamilies break-up at much higher rates than couples in first marriage families. The present research consists of two studies that aimed to investigate these differential outcomes for stepfamily couples by examining the longitudinal relationship between a range of both couple and stepfamily specific variables and relationship satisfaction and stability. The broad aims of the research were to compare the relative contribution of general couple factors that have been found to be associated with relationship outcomes for first married couples as opposed to factors that are specific to stepfamilies. Using growth mixture modelling Study 1 compared the trajectory of couple relationship satisfaction of 370 newlywed stepfamily (n = 155) and first married couples (n = 215) over the first four years after marriage. It was hypothesised that there would be more than one class of trajectory and that stepfamily membership would predict membership in a class of trajectory with steeper declines in marital satisfaction and relationship separation over a four year period. Results partially supported the hypotheses finding that being in a stepfamily was a significant predictor of marital status at time 5 and there were 2 classes of relationship satisfaction with one class experiencing an average decline in relationship satisfaction over time and another class showing stability across the first four years of marriage. However, contrary to hypotheses newlywed couples in stepfamilies were iv
more likely than non-stepfamily newlyweds to be in a trajectory class with higher and more stable relationship satisfaction over the first 4 years of marriage. Study 2 investigated the predictors of relationship satisfaction and stability over a period of 2.5 years in a population of 122 stepfamily couples who were in a committed relationship (married or cohabiting), using both self-report questionnaires and interview data. Contrary to hypotheses this study found that, none of the couple variables of low couple satisfaction, high couple conflict, low couple bond or high couple conflict over parenting issues predicted negative couple outcome at time 2. Instead study 2 found that stepfamily specific factors such as living in a complex stepfamily and displaying high stepfamily disillusionment were predictive of negative couple outcome at time 2. Additionally, high contemplation of separation at time 1 and poor child adjustment also predicted negative couple outcome at time 2. Together the studies found that although newlywed couples in stepfamilies were more likely than non-stepfamily newlyweds to be in a trajectory class with higher and more stable relationship satisfaction over the first 4 years of marriage they were also more likely to break up and that stepfamily specific factors accounted for variance in relationship satisfaction and stability above that accounted for by couple factors. It was therefore concluded that the influence of stepfamily couple relationship satisfaction and stability seem distinctive from first-marriage couples. In light of these findings it was suggested that theories of relationship satisfaction and dissolution should account for these differences in order to better understand the relationship satisfaction and dissolution of stepfamily couples. It was further suggested that relationship education and intervention programs for stepfamilies need to address the unique needs of stepfamilies such as the development of positive stepparent-stepchild v
relationships, increasing stepfamily cohesion, and assisting with child adjustment in order to provide better outcomes for stepfamilies. vi
Contents Declaration... ii Acknowledgements... iii Abstract... iv Contents... vii Table of tables... x Table of figures... xi Chapter 1 - Couple Outcomes in Stepfamilies... 1 Prevalence of stepfamilies... 3 Significance of Stepfamilies... 5 Unique Characteristics of Stepfamilies.... 5 Child Outcomes in Stepfamilies.... 7 Couple Outcomes in Stepfamilies.... 10 Marital Satisfaction... 15 Conclusion... 18 Chapter 2 - Study 1: The trajectory of relationship stability and satisfaction in stepfamilies... 20 The Trajectory of Relationship Satisfaction... 20 Factors associated with the trajectory of marital satisfaction and stability... 29 Summary... 34 Aims and Hypotheses... 35 Method... 37 Participants.... 37 Procedure.... 38 Materials.... 40 Results... 43 Trajectory of marital satisfaction.... 43 Data Screening.... 45 Descriptive Data.... 46 Database preparation and analyses.... 50 Selecting number of classes.... 51 Class Trajectories... 55 vii
Time 1 Factors.... 58 Class Trajectories and Marital Status Outcomes.... 60 Post Hoc Analyses.... 62 Discussion... 64 Limitations of the study.... 71 Potential practical implications of the study.... 73 Conclusion... 73 Chapter 3 - Risk Factors for Relationship Dissatisfaction and Instability... 75 Individual Characteristics... 76 Stepfamily Specific Individual Characteristics... 82 Couple Characteristics... 84 Stepfamily Specific Couple Characteristics... 87 Family Characteristics... 87 Stepfamily Specific Family Characteristics... 89 Environmental Characteristics... 95 Stepfamily Specific Environmental Characteristics... 97 Conclusion... 98 Chapter 4 - Study Two: Predictors of relationship stability and satisfaction within stepfamilies... 100 Multi-Method Assessment Using the Oral History Interview... 104 Relationship Satisfaction and Stability... 105 Research Aims and Hypotheses... 109 Method... 111 Participants.... 111 Materials.... 112 Procedure.... 123 Data Analyses.... 124 Results... 124 Sample Characteristics... 124 Descriptive Data.... 126 Data Screening.... 129 Analysis.... 130 Discussion... 145 Relationship to prior research.... 147 Strengths.... 149 viii
Limitations.... 149 Future directions.... 151 Conclusion... 152 Chapter 5 - General Discussion... 153 Summary of key findings... 153 Discrepancies in Findings across Study 1 and Study 2... 153 Summary of key theoretical implications... 155 Clinical Implications... 156 Suggestions for Future Research... 160 Conclusion... 162 References... 163 Appendix A... 226 Appendix B... 226 Appendix C... 242 Appendix D... 248 ix
Table of tables Table 2.1. Characteristics of the Entire Sample of Couples at Time 1.... 38 Table 2.2. Means, standard deviations and Correlations between the dependant and independent variables for all measures.... 48 Table 2.3. Selection criteria values for competing models.... 53 Table 2.4. Intercept and linear slope means (SE) for both classes.... 57 Table 2.5. Average Latent Class Probabilities for Most Likely Class Membership (Row) by Class (Column).... 58 Table 2.6. Logistic regression for covariates onto class.... 59 Table 2.7. Logistic regression for covariates onto Time 5 Marital Status.... 61 Table 4.1. Code definitions for the Oral History Interview for Stepfamily.... 118 Table 4.2. Inter-coder reliability on Oral History Interview for Stepfamilies... 121 Table 4.4. Means and percentages on sociodemographic characteristics of the sample at Time1.... 126 Table 4.5. Means, standard deviations and correlations between time 1 male and female scores on predictor variables.... 127 Table 4.6. Means and standard deviations of couple questionnaire and video interview data... 129 Table 4.7. Correlations between the dependant variable and independent variables for all measures... 132 Table 4.8. Logistic regression predicting relationship outcome from self-reported time 1 couple, stepfamily, parenting and child adjustment variables.... 134 Table 4.9. Logistic regression predicting relationship outcome from time 1 observational couple and stepfamily variables... 136 Table 4.10. Logistic regression predicting relationship status from time 1 selfreported couple, stepfamily, parenting and child adjustment variables.... 138 Table 4.11. Correlations between the dependent variables (Time 2 relationship stability Time 2 relationship satisfaction) and independent variables for all measures used in regressions.... 140 Table 4.12. Hierarchical multiple regression predicting relationship stability from self report couple, stepfamily, parenting, and child adjustment variables.... 141 Table 4.13. Hierarchical multiple regression predicting relationship stability from observational couple and stepfamily variables... 142 Table 4.14. Hierarchical multiple regression predicting relationship satisfaction from self-report couple, stepfamily, parenting and child adjustment variables... 143 Table 4.15. Hierarchical multiple regression predicting relationship satisfaction from observational couple and stepfamily variables... 144 x
Table of figures Figure 2.1. Growth mixture model with a distal outcome of time 5 marital status.... 44 Figure 2.3. Boscardin et al (2008) mean separating two unique populations. 50 Figure 2.3. Selection criteria values for increasing classes.... 54 Figure 2.4. Entropy for increasing classes.... 55 Figure 2.5. Mean DAS at each time point for the Two Classes.... 56 xi