Melbourne School of Psychological Sciences - Theses

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    Characterising Sleep in Young People with Borderline Personality Disorder
    Jenkins, Claire Anne ( 2021)
    Background. Borderline personality disorder (BPD) features typically have their clinical onset during adolescence and early adulthood, coinciding with normative developmental changes to sleep quality and sleep-wake patterns. Sleep disturbances are commonly reported by individuals with BPD features and are independently associated with a range of adverse outcomes. Yet, few studies have investigated sleep in young people with BPD. Aims. This thesis consists of five studies. Study 1 was a scoping review that mapped the existing literature, highlighted areas for further investigation, and provided methodological recommendations for future research. Study 2 assessed inter-device reliability between two actigraphs (Actiwatch-2 and GENEActiv). This was an essential methodological step in this research program because it allowed actigraphy-derived sleep parameters to be reliably compared across BPD and clinical comparison groups, despite different actigraphs having been used. Studies 3-5 addressed the overarching aim of this thesis: to characterise sleep in young people with BPD features. This involved investigating whether subjective and objective (actigraphy) sleep patterns were non-normative and/or specific to BPD (Study 3), exploring the mechanisms underlying sleep disturbance (Study 4), and assessing the feasibility of using polysomnography in this population and providing pilot data (Study 5). Method. Participants in studies 3 and 4 were 96 young people aged 15-25 years (M = 20.02, SD = 2.62). This included 40 with 3 or more BPD features, 38 healthy individuals, and 18 young people seeking help for non-BPD psychopathology. Sleep was assessed subjectively (self- report questionnaires) and objectively (10 days wrist actigraphy). In study 5, a subset of participants (7 with BPD features, 6 healthy individuals) completed overnight polysomnography monitoring. Results. Young people with BPD features reported poorer sleep quality, more severe insomnia and later chronotype than healthy and clinical comparison groups. Impulse control difficulties, limited access to emotion regulation strategies and anxiety indirectly affected the relationship between BPD features and subjective sleep disturbances. Actigraphy data revealed that young people with BPD features had irregular sleep timing, later rise times, greater time in bed, and longer sleep durations compared with healthy young people. Additionally, individuals with BPD features displayed superior sleep quality (greater sleep efficiency, less wake after sleep onset) and slept longer than the clinical comparison group. Anxiety and lack of emotional awareness indirectly affected the association between BPD features and actigraphy-assessed bedtime variability and longer time in bed, respectively. The feasibility of in-home and sleep laboratory-based polysomnography were both demonstrated. Pilot polysomnography data indicated that individuals with BPD features had fewer arousals from sleep than healthy young people, but displayed an otherwise comparable sleep profile. Conclusion. Young people with BPD features reported sleep disturbances beyond the normative changes found during this developmental period and beyond those reported by young people seeking help for non-BPD psychopathology. Although a subjective-objective sleep discrepancy was revealed, subjective sleep disturbances alone reflect sleep-related distress and thus warrant clinical attention. Sleep-improvement interventions should be investigated as possible beneficial adjuncts to current early interventions for young people with BPD features to improve subjective sleep, quality of life, and potentially promote broader symptomatic and functional recovery.
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    Empathy during childhood; an investigation of associations with anxiety and depressive symptoms, and brain structure and function
    Bray, Katherine Olivia ( 2021)
    This thesis investigated the associations between empathy and internalising (i.e., depressive and anxiety) symptoms, and the underlying structural, and functional connectivity neural correlates of empathy in late childhood. Background: Empathy refers to the understanding and sharing of others’ emotions, is a multidimensional construct, and includes cognitive and affective components. Empathy is important for social functioning, and alterations in empathy have been demonstrated in many developmental/psychiatric disorders. Studies in adults have demonstrated that both cognitive and affective empathy are associated with internalising symptoms. Studies in adults have also examined the neural underpinnings of empathy, implicating two major functional brain networks: the Default Mode Network (DMN) has been implicated in cognitive empathy, while the Salience Network (SN) has been implicated in affective empathy. These findings have mostly resulted from investigating brain activity during empathy tasks (i.e., in functional Magnetic Resonance Imaging [fMRI] studies). Less research has examined the associations between trait empathy, and brain structure or intrinsic functional connectivity. Few studies have investigated these associations between empathy and either internalising symptoms or the neural correlates in young people, particularly children. Investigating associations between empathy, mental health, and brain structure and function during childhood is beneficial to begin to build a comprehensive picture of the development of empathy components and the neural correlates of empathy across the lifespan. Based on previous research in adults and preliminary work in children, we hypothesised that higher levels of empathic distress and lower levels of cognitive empathy would be associated with higher depressive and anxiety symptoms (particularly social anxiety symptoms). We also hypothesised that children’s cognitive and affective empathy would be associated with individual differences in brain structure and function within areas related to the DMN and the SN, respectively. Methods: Participants were 9- and 10-year-old children, a subset from the second wave of the Families and Childhood Transitions Study (FACTS), a longitudinal, community-based cohort study. Sample size across the empirical chapters of the thesis differed depending on measures completed and quality of brain images (study 1 n =127, study 2 n = 125, study 3 n = 112). Self-report measures of empathy (cognitive empathy, affective empathy: affective sharing, empathic concern, empathic distress) and internalising (anxiety and depressive) symptoms were administered, as well as a task-based measure of cognitive empathy. To investigate associations between empathy and internalising symptoms (study 1), canonical correlation analysis (CCA), a multivariate technique, was employed. Participants underwent MRI of the brain where T1-weighted structural images and resting-state functional sequences were collected. Grey matter volume, cortical thickness (study 2), seed-to-whole-brain and dual regression resting-state functional connectivity (study 3) were examined. Results: Study 1: CCA demonstrated that components of affective empathy, specifically affective sharing and empathic distress, were associated with internalising (particularly social anxiety) symptoms. Cognitive empathy was not associated with internalising symptoms. Study 2: In region of interest analyses, individual differences in affective and cognitive empathy were related to grey matter volume in the insula and the precuneus. Although these associations were of similar strength to those found in previous research, they did not survive correction for multiple comparisons. While no associations were detected between grey matter volume and empathy in exploratory whole-brain analysis, associations were found between empathic concern and cortical thickness in the right precentral gyrus. Study 3: Seed-to-whole-brain resting-state functional connectivity analyses demonstrated that both affective sharing and empathic distress were associated with decreased connectivity between key hubs of the DMN (precuneus and temporal parietal junction) and other widespread areas in the brain. Analyses of resting-state networks demonstrated that cognitive empathy was associated with both increased and decreased connectivity between dorsal and lateral regions of the DMN and regions outside of the DMN, including the pre- and postcentral gyrus, and the cerebellum. Affective empathy was associated with increased connectivity between the anterior SN and the pre- and postcentral gyrus. These relationships did not survive strict correction for multiple comparisons. Conclusions: Findings suggested that children who share others’ emotions strongly are more likely to experience anxiety, particularly of a social nature. This study also provided preliminary evidence that individual differences in self-reported empathy in children may be related to certain aspects of brain structure and functional connectivity. Overall, we observed less clear dissociations between the neural correlates of affective versus cognitive empathy, and more widely spread involvement from other brain areas. This potentially indicates reduced maturation and specialisation of the systems underlying affective versus cognitive empathy in this age group. However, more research is required to demonstrate reproducibility of the findings. More research investigating the mental health associations and neurobiological correlates of empathy in children is needed, particularly of a longitudinal nature, to track these changes across development. One limitation of our study is that the majority of our findings were based around self-report measures of empathy, which may not accurately reflect empathic ability.
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    The influence of aesthetic judgements on attributions of moral standing
    Klebl, Christoph Michael Josef ( 2021)
    Beauty and ugliness judgements are everyday psychological phenomena; however, the function of aesthetic judgements is not yet well understood. In the present thesis, I propose that aesthetic judgements influence the degree to which targets are viewed as possessing moral standing (i.e., are worthy of protection for their own sake). Furthermore, the present thesis sought to identify one psychological mechanism through which aesthetic judgements influence moral standing attributions: beauty and ugliness judgements may affect moral standing attributions through processes aligned with the disease-avoidance system. Chapter 2, published in Social Psychological and Personality Science (five studies; N = 1,552), found that ugliness judgements are closely associated with the disease-avoidance system (over and above general negative affect): ugly faces, animals and buildings were found to elicit the emotion of disgust, and pathogen cues were found to evoke ugliness judgements. Investigating the implications of these findings for person perception, Chapter 3 (four studies accepted at Personality and Social Psychology Bulletin; N = 1,778) revealed that physical attractiveness particularly biases moral character judgements pertaining to the moral domain of purity—a domain particularly relevant to the disease-avoidance system. Specifically, these studies found that unattractive individuals were judged as more likely to engage in purity violations (i.e., acts that are associated with pathogen threat) than attractive individuals, and that this effect was stronger than for judgements of harm violations. Across six studies, Chapter 4 (published in Personality and Social Psychology Bulletin; N = 1,662), tested the main prediction of the thesis, revealing that people attributed more moral standing to beautiful than ugly sentient entities (i.e., animals and people) and non-sentient entities (i.e., landscapes and buildings). This effect was consistently mediated by perceptions of purity, suggesting that perceptions of purity are a psychological mechanism through which beauty signals the moral standing of targets. Building on these findings, Chapter 5 (two studies published in Journal of Environmental Psychology; N = 942) investigated whether the effect of aesthetic judgements on moral standing attributions is independent from other qualities that have been previously linked to moral standing. As predicted, people attributed more moral standing to beautiful than to ugly animals, independent of from the degree to which the animals were perceived to have mental capacities and dispositions to cause harm, as well as the degree to which they were judged to be familiar, similar to humans, and edible. In summary, the present thesis shows that aesthetic judgements influence the degree to which people attribute moral standing to targets, independently from other factors likely to affect moral standing. That is, people perceive beautiful entities as more worthy of protection for their own sake than ugly entities. It also demonstrates—based on key findings that aesthetic judgements are closely linked to the disease-avoidance system—that purity judgements are the psychological mechanism through which people attribute more moral standing to beautiful (vs. ugly) targets.
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    Fear of Positive Evaluation and Core Beliefs in Social Anxiety
    Cook, Sarina Isobelle ( 2021)
    Social Anxiety Disorder is characterised by feelings of distress and avoidance of socially evaluative situations. It has long been theorised in cognitive-behavioural research that core beliefs and thinking patterns related to fear of negative evaluation result in symptoms of social anxiety, with fear of negative evaluation thought of as a selected evolutionarily sensitivity to the threats posed by social rejection. More recently however, evolutionary models have focused on the fear of positive evaluation as a sensitivity to the threats posed by social competition. Cognitive models that focus on fear of negative evaluation theorise that socially anxious individuals perceive a high standard that they lack the skills to reach, resulting in fear of negative evaluation, and the desire to avoid the situation that risks rejection. While this is well-developed and established, the cognitive theories related to fear of positive evaluation are less developed, with a focus on disqualifying positive social outcomes to avoid the perceived threat of competition. To date, no comprehensive model has been developed, however. There remain inconsistencies within the literature, with some fear of negative evaluation models suggesting that socially anxious individuals seek positive evaluation, while others suggest that positive evaluation is feared. It remains unclear whether fear of positive evaluation is a unique component of social anxiety or merely an anticipation of future negative evaluation. To address the question of whether fear of positive evaluation is distinct from fear of negative evaluation, a systematic search and meta-analysis of 147 papers since 2008 was undertaken. The results suggested that fear of positive evaluation was moderately correlated with social anxiety symptoms, explained 6-9% of unique social anxiety variance beyond fear of negative evaluation, and was also reported more by socially anxious individuals relative to healthy comparison individuals. It was concluded that fear of positive evaluation plays a unique and important role in social anxiety. Building upon the finding that fear of positive evaluation plays a unique role, a model of social anxiety symptoms was developed to test it was then tested whether the core beliefs underlying fear of negative evaluation, such as high standards, explain similar or a different amount of variance relative to fear of negative evaluation in. The results suggested that high standards, while explaining some variance in fear of negative evaluation, did not relate to fear of positive evaluation and explained considerably less variance. It was concluded that core beliefs differ between the fears of evaluation and that a measure of core beliefs for fear of positive evaluation was needed. The final study developed and validated the Positive Evaluation Core beliefs Scale, a measure of core beliefs related to fear of positive evaluation with robust psychometric properties. Testing several core belief measures, it was found that fear of negative evaluation was best predicted by high standards and a preoccupation with social rank, whereas fear of positive evaluation was best predicted by hiding one’s talents, expecting pressure to perform, and hiding one’s authentic self. It was concluded that fears of positive and negative evaluation were associated with separate sets of core beliefs. The results of this thesis make a significant and important contribution to the literature by confirming the unique role of fear of positive evaluation in social anxiety, and by exploring the unique belief systems associated with each fear of evaluation. This has implications for both research and clinical practice in terms of offering insights into the hitherto less-well developed fear of evaluation to help enhance and further develop the cognitive-behavioural framework for social anxiety disorder.
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    Helping others has an existential function: The relationship between prosociality and meaning in life
    Dakin, Brodie ( 2021)
    Meaning in life is a core aspect of psychological well-being. For this reason, finding meaning is highly desired, and identifying the practices that enable the experience of meaning is an important avenue of research. In this thesis, I sought to unpack how prosociality is relevant to meaning in life, including how prosociality is related to experiencing meaning (Chapters II and III), and how searching for meaning is related to prosociality (Chapters IV and V). In Chapter II, I completed a systematic review of the prosociality—meaning relationship and found that prosociality and meaning are generally positively related in the existing empirical literature. Chapter III extended this with two daily diary studies (Studies 1-2) examining how prosociality in everyday life was related to experiencing meaning and happiness. Study 1 found that within-person increases in subjective prosociality were associated with experiencing greater meaning and happiness on the same day. Study 2 found that self-reported prosocial acts were also significantly associated with increases in daily meaning, but were less robustly associated with happiness. Results from Chapters II and III complement findings from a growing literature suggesting that prosociality is a robust ‘source of meaning’ in life. In Chapter III (Studies 3-7), I extended from this premise and examined whether searching for meaning is linked with prosociality, particularly for prosocial acts that are costly for the self. Across these studies, searching for meaning was positively related to the motivation to perform costly prosocial behaviours, and to reporting enactment of costly prosocial behaviours in the recent past. Meaning-seekers were also shown to have stronger intentions toward costlier prosocial acts compared to less-costly alternatives (Studies 5-6). Further, it was found that, unlike meaning-seeking, pursuing happiness was not clearly linked with costly prosociality (Studies 4-5). Finally, in Chapter V, I re-analysed data from Study 2 using a daily search for meaning measure, and showed that on days when a person experiences an increased need to seek meaning, they become more likely to perform a prosocial act. In summary, the thesis’ findings suggest that performing prosocial actions is associated with experiencing greater meaning in life, and that searching for meaning is linked to prosocial behaviour, particularly when costly for the self.
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    Moral, yet more than agreeable: The enlightened tendencies of open people
    Lawn, Erin Carol Rose ( 2021)
    Openness/Intellect is a basic personality trait describing the tendency to be curious and imaginative. Although these cognitive exploration tendencies are not inherently other-regarding, and open people are not disposed toward prosociality in general, Openness/Intellect has at least some important but underappreciated prosocial correlates (e.g., Parks-Leduc, Feldman, & Bardi, 2014; Sibley & Duckitt, 2008; Soutter, Bates, & Mottus, 2020), suggesting the potential moral significance of this trait may have been overlooked. In this thesis, I aimed to clarify whether and in what ways Openness/Intellect is a morally significant personality trait through assessing its associations with specific forms of prosociality that are likely to benefit from cognitive exploration proclivities. In Stream One, I explored (Study 1; N = 119) then sought to confirm (Studies 2-4; combined N = 987) an ostensible association between Openness/Intellect and cooperative behaviour, a major subtype of prosociality that involves coordinating with others toward mutual goals. Cooperativeness was operationalised using the Public Goods Game, a behavioural paradigm that strips cooperation to its elementary components. Despite finding a sizeable correlation in my exploratory study, Openness/Intellect shared only a very modest (though nonnull) correlation with cooperative behaviour across my confirmatory studies, suggesting open people are not meaningfully disposed toward cooperativeness in its most elementary form. After introducing the concept of moral exceptionality, in Stream Two (Studies 1-3; combined N = 3,003) I turned to the question of whether Openness/Intellect—in combination with the more explicitly prosocial trait Agreeableness—can account for individual differences in the tendency to show regard for others in ways that are flexible and inclusive (vs. rigid or parochial). Results revealed that such morally exceptional expressions of prosociality can be summarised and measured as a trait—enlightened compassion—that correlates strongly with Openness (an aspect of Openness/Intellect) as well as Compassion (an aspect of Agreeableness), thereby constituting an interstitial facet of the Openness/Intellect and Agreeableness domains. Together, the results from Streams One and Two suggest that although Openness/Intellect is not robustly associated with more elementary expressions of prosocial behaviour, open people are likely to think, feel, and desire in more prosocial ways under circumstances that involve transcending the boundaries of parochialism. To the extent that this enlightened compassionate orientation translates into actual behaviour, open people can be said to exhibit a kind of moral exceptionality.
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    Harm-related concept breadth: Variability in understandings of prejudice, bullying, trauma, and mental disorder
    McGrath, Melanie ( 2021)
    Concept creep is the gradual semantic broadening of harm-related psychological concepts such as bullying, prejudice, trauma, and mental disorder (Haslam, 2016). If, as concept creep theory suggests, understandings of harm-based psychological concepts are undergoing a process of expansion, a cross-section of individuals might demonstrate different rates of adoption of these shifting meanings. This program of study sought to 1) empirically demonstrate individual differences in ‘harm concept breadth’ (HCB), 2) determine their structure, 3) develop a nomological network for HCB, and 4) test two models of HCB’s psychological basis. Study 1 developed the 40-item Harm Concept Breadth Scale, including refining an item pool, evaluating internal consistency, and preliminarily testing the latent structure of HCB. Study 2 and Study 3 replicated the internal consistency and latent structure of the scale, and established relationships between HCB and measures of sensitivity to self- and other-directed harm, conceptual inclusiveness, gender, and political orientation. Study 4 tested a sociodemographic model in which childhood material security predicts HCB via endorsement of postmaterialist values. Both variables predicted greater HCB, suggesting that satisfaction of material needs and values prioritising wellbeing and egalitarianism are independently related to holding broader concepts of harm. Study 5 investigated a mechanism by which childhood material security might influence HCB. The differentiated threat sensitivity model proposes two higher order threat dimensions: sensitivity to material and non-material threats (e.g., injury and disease versus exclusion and negative evaluation). In the model, threat perception is sensitised to relevant stimuli during childhood, and this differentiated sensitivity influences HCB. Material and non-material threat sensitivity dimensions were empirically distinguished. Non-material threat sensitivity was found to uniquely predict HCB, but did not mediate the relationship between childhood material security and HCB. Study 6 and Study 7 experimentally tested the causal effect of non-material threat sensitivity on HCB. In Study 6 an exclusion threat manipulation (Cyberball; Williams & Jarvis, 2006) had no effect on HCB. In Study 7 a novel experimental paradigm tested the effect of evaluative threat on HCB. Consistent with the differentiated sensitivity model, evaluative threat had an indirect effect on HCB via fear of negative evaluation. This research program makes several theoretical and practical contributions to the field. HCB is a novel construct with implications for a range of significant social phenomena. Disparities in breadth of harm-based concepts may play a role in ideological polarisation and conflict regarding the moralisation of social behaviours. Greater understanding of factors that increase sensitivity to concepts such as trauma and mental disorder may prove valuable in identifying vulnerabilities to psychological harm. This research develops the first reliable and valid measure of HCB. A further theoretical innovation is the identification of higher order dimensions of threat sensitivity, providing fertile ground for revisiting literature linking unidimensional threat to social psychological phenomena. In sum, this thesis provides the first exploration of a novel construct with theoretical and practical implications for our understanding of political polarisation, moral disagreement and vulnerability to psychological harm
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    Depression in Recent Onset Schizophrenia Spectrum Disorders
    Herniman, Sarah Elizabeth ( 2021)
    It is unclear whether the depression experienced by individuals with recent onset schizophrenia spectrum disorders (termed SSD hereafter) is similar or different to the depression experienced in recent onset major depressive disorder (MDD), and whether it is best conceptualised as distinct from or intrinsic to SSD, particularly in the psychotic phase. A better understanding of depression will aid in improving early recognition and treatment of depression to improve outcomes in SSD. The overarching aim of the current research program was to gain a better understanding of the extent and phenomenology of depression in SSD. Only then can appropriately tailored treatments for depression be recommended in SSD. The current research program comprised four studies, the primary aims of which were to determine: (1) the extent of depression — based on different operationalisations — across the psychotic and post-psychotic phases in SSD; (2) how depression should be assessed in SSD; (3) the specific phenotype of depression in SSD and how it compares to MDD; (4) and whether depression is best conceptualised as a distinct or intrinsic feature of SSD in the psychotic phase. Methods included systematic review and meta-analysis (Study 1), and network analyses of cohort or trial data (Studies 2 – 4). The systematic review was conducted in accordance with an a priori protocol, registered with the International Prospective Register of Systematic Reviews (PROSPERO; CRD42018084856), and conforming with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) and Meta-Analysis of Observational Studies in Epidemiology (MOOSE) guidelines. Studies 2 – 4 involved individuals with recent onset SSD (drawn from the Psychosis Recent Onset GRoningen Survey [PROGR-S]) or recent-onset MDD (unipolar, without psychotic features; drawn from the Youth Depression Alleviation [YoDA] trials). Measures included the Montgomery–Asberg Depression Rating Scale (MADRS) and Positive and Negative Syndrome Scale (PANSS). Key findings were: (1) that depression is highly common in SSD, and is even more common and severe in the psychotic compared to post-psychotic phase (Study 1); (2) that depression can be assessed with the Montgomery–Asberg Depression Rating Scale (MADRS) — a depression scale designed for use in MDD but not SDD — but that specific tailoring is needed to ensure its validity in SSD (Study 2); (3) that the specific phenotype of depression might be different in SSD compared to MDD; while sadness is the hallmark of depression in both SSD and MDD, individuals with SSD are more likely to present with atypical neurovegetative features including increased sleep (Study 3); and (4) that depressive symptoms are highly interrelated with positive symptoms, and negative symptoms pertaining to deficits in motivation and interest, in the psychotic phase of SSD (Study 4). Rather than being conceptualised, assessed, and treated as a comorbidity akin to MDD, depression might be better conceptualised as intrinsic to SSD, with assessment and treatment needing to be tailored accordingly. Limitations included the use of assessment models developed in MDD to gain a better understanding of depression in SSD, and the cross-sectional design. Future mixed methods research is needed to gain a more in-depth and phenomenologically valid understanding of depression in SSD and, in turn, develop a new scale for its recognition and assessment. Then, using this new scale, research is needed to model the trajectory and psychophysiological mechanisms of depression in SSD. This would improve early and accurate recognition of depression in SSD and reveal when and how to treat it, and ultimately contribute to better outcomes for individuals with SSD.
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    Towards an Understanding of Cosmetic Surgery Stigma
    Bonell, Sarah ( 2021)
    Cosmetic surgery is extremely popular. Despite this, negative attitudes towards cosmetic surgery and its recipients prevail. This thesis contains five manuscripts that examine pervasive perceptions of cosmetic surgery in contemporary society. The first manuscript contained within this thesis empirically demonstrates that cosmetic surgery recipients face stigmatisation; namely, that recipients are assumed to be less warm, competent, moral, and human than non-recipients. The second manuscript is a narrative review that examines the cosmetic surgery paradox – a contemporary phenomenon whereby women are conflictingly both compelled to undergo cosmetic surgery and condemned for doing so. Specifically, this manuscript describes how unattainable beauty standards for women are responsible for popularising cosmetic surgery on a societal level while contributing to the individualistic stigmatisation of its recipients. Manuscript three further explains why cosmetic surgery recipients may face stigmatisation. By examining cosmetic surgery stigma through a moral lens, this manuscript suggests that preferences for ‘naturalness’ might drive the societal condemnation of cosmetic surgery (i.e., cosmetic surgery is wrong because it is unnatural). Manuscript four depicts cosmetic surgery recipients’ anecdotal lived experiences of stigmatisation. Findings from this manuscript suggest that women who undergo cosmetic surgery are aware of the stigmatisation they face, internalise this stigmatisation, and actively employ strategies to navigate and manage this stigma on a day-to-day basis. Finally, manuscript five examines whether intrasexual competitiveness compels women to derogate and socially exclude cosmetic surgery recipients. Contrary to our predictions, manuscript five demonstrates that intrasexual competitiveness does not motivate cosmetic surgery stigma. Overall, findings from these five manuscripts considerably broaden our understanding of cosmetic surgery stigma. In particular, this thesis suggests that cosmetic surgery recipients are stigmatised because of pervasive societal preferences for natural beauty and that recipients ongoingly manage experiences of stigmatisation. Taken together, findings provide building blocks upon which interventions for eradicating cosmetic surgery stigma may be built.
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    The Big Five: Towards a Taxonomy of Psychological Trait Scales
    Bainbridge, Timothy Francis ( 2021)
    Many personality psychologists argue that the Big Five (Goldberg, 1990) provides an organising framework for psychological traits. However, in the wider psychology literature, the Big Five is frequently not adopted as an organising framework for stand-alone psychological trait scales. In the current thesis, I aimed to: evaluate whether the Big Five could accommodate these stand-alone scales; examine whether scale users could navigate the Big Five effectively; and consider impediments to the wider adoption of the Big Five (or a comparable taxonomy, e.g., the HEXACO; Lee & Ashton, 2004). In Chapter 2, I developed a method to assess how well the Big Five could accommodate stand-alone scales. In Chapter 3, I applied this method in three convenience samples, followed by a community sample in Chapter 4. In Chapter 5, I evaluated the accuracy of psychological researchers predictions of associations between stand-alone scales and the Big Five domains to determine how well they could navigate the Big Five. In the General Discussion, I explored further challenges to the Big Five's wider adoption. In Chapter 2, various shortcomings with using Exploratory Factor Analysis and Extension Analysis for the present task were identified, before an Exploratory Structural Equation Modelling (Asparouhov & Muthen, 2009) approach was selected. Applying this method in Chapter 3, the Big Five accommodated over 70% of stand-alone scales, such that many of the scales assessed might reasonably be considered Big Five facets. Many stand-alone scales demonstrated incremental validity beyond the Big Five domains, but so did Big Five facets. This can be understood in terms of the bandwidth-fidelity trade-off. In Chapter 4, nearly half the stand-alone scales could be readily located within the Big Five. The result was less compelling than that of Chapter 3, but was likely attributable to methodological factors that diminished or obscured associations between the Big Five and stand-alone scales in the sample. In Chapter 5, psychological researchers were reasonably accurate regarding the locations of stand-alone scales within the Big Five. Based on these findings, I concluded that the Big Five would be an appropriate organising framework for stand-alone psychological trait scales, both in principle and in practice, and ought to be widely adopted as such. However, many researchers may remain indifferent to the Big Five if they perceive it to be of little benefit to their field, or hostile if they believe adopting the Big Five would undermine their fields' research programs. To counteract these objections, I argued that the wide adoption of the Big Five as an organising framework for stand-alone scales may accelerate scientific progress via reduced fragmentation or better measurement of existing constructs. I also suggested an integrative pluralism approach—whereby stand-alone scales with incremental validity beyond the Big Five continue to be used, but their relationships to the Big Five are acknowledged and incorporated into discussions of research outcomes. I finished by considering the scope of scales that ought to be included and the challenge posed by alternative frameworks.