Exploring the relationship between implicit self-esteem, paranoia, and trustworthiness judgements of faces : a systematic review and causal-interventionist study

Psychological theory and research has sought to explore paranoia, self-esteem, and trust extensively across clinical, social, behavioural, evolutionary, and neuropsychological fields. Understanding the role of these psychological mechanisms and the potential relationship between them is essential in order to develop psychological interventions for clinical practice. Research has found that negative self-esteem is associated with severe mental health difficulties such as depression and paranoia. In addition, paranoia is associated with mistrust and insecure attachment styles, which appear to interact with negative self-esteem. To contribute to our understanding of how psychological mechanisms may influence emotional and psychosocial functioning and the potential relationships between them, this research examined whether a novel evaluative conditioning paradigm would increase implicit self-esteem and implicit trust, and consequently reduce paranoia and depression. Part I of this thesis presents a systematic review which aimed to explore the relationship between paranoia and trustworthiness judgments of faces. Eleven relevant articles were included in this review; conceptualisation and operationalisation of paranoia and trust were examined and the relationship between these two variables assessed. Overall, the findings of this review were mixed regarding conceptualisation and operationalisation of paranoia and trustworthiness judgments of faces and the relationship between them. Study design, quality, conceptualisation, and measurement of the key variables did not appear to influence whether a relationship was found. This review was limited by the small number of eligible studies and the heterogeneity between study quality, designs, and analysis, and consequently a meta-analytic review was not possible. Future research is needed using consistent study designs, conceptualisations, and measures of paranoia and trust to further explore the relationship between the variables of interest and provide opportunities for a meta-analytic review. Future research would also benefit from incorporating additional measures of mood e.g., depression and anxiety, to control for potential confounding variables. Part II of this thesis presents an experimental causal-interventionist study which aimed to investigate whether a novel evaluative conditioning task would improve implicit self-esteem and trust and therefore decrease paranoia and depression. An analogue sample of 211 participants was randomly allocated into either the experimental evaluative conditioning task or an equivalent control conditioning task. Baseline trait measures of psychological difficulties and attachment were collected in addition to pre- and post- measures of implicit and explicit self-esteem, paranoia, trust, and attachment. Although the evaluative conditioning paradigm did improve implicit self-esteem, this did not result in improved trustworthiness judgements or decrease subclinical paranoia or depression. There was a marginal increase in explicit self-esteem for both the experimental and control conditions. Following the evaluative conditioning paradigm, attachment anxiety unexpectedly deteriorated. The study's findings that increasing implicit self-esteem did not improve trustworthiness judgements or reduce paranoia or depression contrasts with psychological research and theory. Consequently, replication to confirm the findings of this study in future research is necessary. In addition, future studies should seek to test this paradigm with a clinical sample. The limitations of this study are discussed, alongside clinical implications and recommendations for future research.