Tang, Stephen2017-05-192017-05-19b43751659http://hdl.handle.net/1885/116972This thesis advances a psychological model of indecision and indecisiveness by way of a functionalist approach to decision-making. Understanding how and why people have difficulty making decisions requires looking beyond the content and outcomes of a decision problem. It requires identifying the multiple motivations, expectations and experiences of the decision-maker. The first part of the thesis is a metatheoretical and theoretical exposition to make room for the functionalist underpinnings of indecision and indecisiveness. This begins with recognising that decision-making is a psychological activity over time which involves the exercise of the decision-maker’s agency. After reviewing the limited literature on indecision and indecisiveness, a new model is proposed based on three functional motivations of a decision-maker: (i) attaining good decision outcomes, (ii) managing the demands of a good decision-making process, (iii) and being a good decision-maker. Successfully realising each of these motivations can be difficult, resulting in indecision. Indecision is compounded when multiple motivations collide within a decision event. The present model posits that each decisional motivation corresponds to a distinct indecision process, namely outcome indecision, process indecision and self-presentation indecision. These indecision processes are influenced by aversive and avoidant forms of indecisiveness, which draw attention to different aspects of a decision and the decision-maker. Three studies tested and refined this model. Study 1 provided factor-analytic evidence of aversive, avoidant and ruminative dimensions of indecisiveness using a composite trait measure. The characteristics and effects of each dimension were evident when correlated against other personality constructs and measures relating to a recalled recent experience of indecision. Study 2 used two contrasting decision-making tasks to elicit process indecision and account for some antecedents of outcome indecision. Behavioural, process-tracing, self-report and psychophysiological data indicated that such indecision could be expressed in both approach and avoidant ways depending on the interaction between indecisiveness, appraisals of the task and self-regulatory capacity. Study 3 was a novel behavioural decision-making task in which participants’ attention was drawn to different aspects of being a decision-maker. In addition to replicating key previous findings, the results showed evidence of self-presentation indecision when participants’ identity as an indecisive person was salient. Finally, the thesis considers the implications of the model for the conceptualisation and treatment of clinical indecision. A proposal for the transdiagnostic psychological treatment of indecision is set out based on the functionalist model.enIndecisionindecisivenesspsychologydecision-makingdecision makerjudgment and decision makingclinical psychology201710.25911/5d7391fb34eb6