Prediction of bulimic behaviors: social learning analysis
The current study investigated the relationship between principles of social learning theory and binge eating episodes in 31 normal weight bulimic women. Participants were asked to monitor the following: (1) levels of self-efficacy related to resisting the urge to binge and/or purge as well as levels of self-efficacy related to handling stressful events, (2) mood states, (3) enjoyment of daily activities, (4) number of stressful events, and (5) number of binging and purging episodes. Participants were asked to monitor these events four times a day for seven days. Measures of locus of control and enjoyment ratings of binging and purging were also gathered prior to monitoring. Results indicated that components of social learning theory predict number of binging and purging episodes. The best predictors were a combination frequency of binging, lowered levels of self-efficacy to resist the urge to binge, and having a general tendency to not feel in control of one's response-outcomes. However, heterogeneity within the group was apparent in that the predictive models failed to significantly predict binging and purging for all participants. It was also the case that there were differences in predictors of binging and purging on an individual level of analysis. For all individuals, self-efficacy to resist the urge to binge/purge was the only consistent predictor of these episodes. For four individuals, frequency of prior binging was an important predictor. Post-hoc analyses suggest that for the group as a whole self-efficacy expectancies affect current behavior more than current behavior affects future expectancies. Even here, variability exists at the individual level of analysis. For four participants, behaviors were more strongly related to subsequent expectancies than expectancies were related to subsequent behaviors. These findings increase our understanding of the role of social learning theory in predicting episodes of binge eating and purging, often thought to be a cycle of maladaptive, negatively reinforced behaviors. The results also have important implications for assessment and treatment of bulimia using a cognitive/behavioral model. The presence of individual differences in the applicability of the predictive models and the relationships between expectancies and behaviors over the course of several time periods suggests that a treatment approach emphasizing the relationship between expectancies and behaviors may have more or less meaning for different individuals. Future research should replicate, cross-validate and expand these findings in order to clarify these issues.