Young people face a number of important changes as they embark on their university studies and previous research has suggested that self-compassion and psychological resilience are likely to be the protective factors for young people during this transition point. To date, no research has focused on self-compassion, psychological resilience among Thai and British students. Furthermore we are yet to develop an understanding of how social media amongst other factors affects self-compassion and psychological resilience, in particular how social media use might help students to better deal with potential difficulties in their lives. The aim of this thesis was to explore the factors that affect self-compassion and psychological resilience among Thai and British university students and to explore the role that social media use has on these constructs. Using a mixed methods approach, a total of 767 University students (482 Thai and 285 British undergraduate students) completed a questionnaire examining the predictors of self- compassion and psychological resilience and this was then followed up with 42 in-depth semi structured interviews (21 Thai and 21 British undergraduate students). The results of the questionnaire showed that personal factors and social media factors were predictors of self-compassion in both Thai and British students. In addition, social support and perceived success influenced psychological resilience among Thai and British students. The qualitative data showed that Thai and British students had experienced similar kinds of problems, for example, academic problems and relationship difficulties. The findings highlighted the importance of family and friends for helping Thai and British students to deal with difficulties in life while teachers and social media also had a small but important role to play. Finally, the findings highlighted that the different cultural dimensions had a vital effect on understanding self-compassion, psychological resilience and social media use in Thai and British students. These findings provide insights for Thai and British university lecturers as to how to use social media to enhance self-compassion and psychological resilience in their students. They also provide beneficial information for Thai and British university lecturers and psychologists to develop programs to enhance Thai and British students’ self-compassion, psychological resilience and effective social media use. Finally, the findings of this thesis will help Thai and British university lecturers, counsellors or psychologists to assist vulnerable students in dealing with the difficulties they face in an appropriate manner.

Over the last decade, the nature of bullying has changed dramatically, moving from traditional, face to face to via communication technologies. The associated bullying behaviours and technologies is collectively known as ‘cyberbullying’. Cyberbullying is an increasing problem which results in negative outcomes for all involved. For victims, it is ubiquitous; there is no escape. Cyberbullying, has been directly and indirectly linked to an increased risk of suicide for both victims and bullies. It is therefore vital to explore what children, parents and teachers interpret as cyberbullying and how to design effective interventions to reduce cyberbullying and/or develop resilience and coping strategies. To date, research on cyberbullying has focussed on children in their teens. However, little is known about the perceptions of younger children particularly at the key transitions point from primary to secondary school. At this age, self-esteem decreases and peer support and influence become very important in determining behaviour. Technology use increases around this age and parental monitoring decreases. This thesis uses multiple methods to fully explore similarities and differences in perceptions and experiences between children before (aged 10-11 years) and after (aged 12-15 years) this transition and develops a behaviour change intervention to promote more positive behaviour online, increase resilience and self-efficacy. This thesis aims to develop ways for children to overcome adversity by developing their problem-solving skills and increasing their confidence levels to deal with a negative situation through building their cyberbullying resilience. Cyberbullying resilience can be strengthened through external factors such as a supportive environment, strong peer support and a sense of belonging and internal factors including high self-esteem, self-control and self-efficacy (Bozak (2013) as cited in Hinduja and Patchin (2017)). Initial findings suggested that cyberbullying is predominantly a female behaviour and that victims and bystanders are reluctant to seek adult intervention unless the situation is considered to be so extreme that they can no longer cope. Primary girls were found to be more likely to report a cyberbullying incident than secondary, even though there was no difference in their perception of the severity of the incident. This thesis adds to the literature by highlighting children, parents and teachers’ understandings and expectations around reporting and what these are. This thesis identifies age differences in relation to cyberbullying perceptions and reporting channels and presents a behaviour change intervention which increased self-efficacy and resilience levels. It is also applies a unique intervention approach by introducing implementation intentions with the intention to increase kind online behaviour in addition to building self-efficacy, self-esteem and cyberbullying resilience so that children have skills and strategies in place to deal with adversity online should the time come.

Type D personality is characterised by high levels of social inhibition and negative affectivity, and is traditionally associated with poor prognosis and negative outcomes in cardiac patients. Research has also demonstrated links between Type D personality and adverse health outcomes among other clinical populations, and in apparently healthy individuals. A number of psychophysiological mechanisms have been suggested to underpin the relationship, including sympathetic dysregulation and maladaptive immune activation. However, previous findings are relatively inconclusive, and further exploration of potential psychobiological mechanisms is warranted. This project therefore aims to elucidate the potential mechanisms underpinning the relationship between Type D personality and poor physical health in the general population. In the current project, physical symptom clusters were derived from an existing tool designed to assess everyday health complaints, in order to ascertain the relationship between specific physical symptom clusters and Type D. Subsequently, a cross-sectional online questionnaire-based study was conducted to assess the associations between Type D personality and physical symptoms, in addition to a number of psychological and behavioural outcomes identified in the literature. Relationships between Type D and specific stress-related symptom clusters were observed. Subsequently, a one-year follow up was conducted to determine the dynamic nature of the Type D-health relationship and the potential mediating factors involved. Type D was related to metabolic, gastrointestinal and cold/flu symptom clusters, and anxiety and stressful life events were found to play mediating roles. Given the findings regarding Type D and stress-related symptoms, the subsequent phase of the project comprised an experimental study, which objectively examined sympathetic arousal in response to an acute stress task, in addition to inflammatory activation. Findings indicated that sympathetic dysregulation may be involved in the Type D-health relationship. Finally, a positive writing intervention was implemented to assess whether the influence of Type D on physical symptoms may be attenuated by means of increasing positive emotions. The utility of the intervention was demonstrated for reducing cold symptoms in Type D individuals over one month. Overall, this project provides novel contributions to the literature on Type D and adverse health, demonstrating links with specific symptom clusters, further evidence of a potential mechanism of sympathetic dysregulation and the value of a positive psychology invention in Type D individuals.

Background: Females assess the quality of potential mates based on the expression and presence of evolved cues and signals. Recent evidence shows that social information gained by observing the mate choices of same-sex peers can also influence mating decisions of females, i.e. mate choice copying (MCC). In humans, much of the MCC literature has focused on confirming the expression of this behaviour in women. Whilst findings are mixed, most research concludes that women do engage in MCC. Recent years have seen a shift away from confirming MCC in humans towards understanding how MCC alters the perception of traits possessed by males. Aims: This thesis sought to expand upon this research arc in three novel ways. First, it examines the interaction between known biological modulators of mate choice and MCC. Second, it explores the interaction between participant individual differences and MCC. Third, it investigates how MCC influences the perception of traits that are likely to increase the probability that a given male is selected as a mate. Method: Facial photographs of attractive and unattractive men were presented to participants in one of three conditions: i) men alone, without an accompanying image of a woman, and described as romantically single; ii) men presented alongside an attractive woman and described as her romantic partner; and iii) men presented alongside an unattractive woman and described as her romantic partner. Participants rated the photographs of men on questions specifically related to the three aims of this thesis. Results: Age and hormonal fluctuations associated with ovulation did not significantly alter MCC behaviour. There were no significant differences in MCC between younger and older participants, or between women at high or low fertility. Men who benefitted from MCC were perceived as significantly more faithful potential partners and were perceived as easier to acquire mates than men not benefiting from MCC. However, when participant individual differences (e.g. socio-sexual orientation, self-perceived mating success, self-esteem, big 5 personality factors and the dark triad factors) were factored into the analysis, MCC effects disappeared. Conclusion: Overall, MCC failed to replicate in 6 out of 7 experimental chapters contained within this thesis. This lack of replication occurs for both the novel, never before tested questions, but also for questions commonly asked and replicated in wider MCC literature. Replication failure raises questions about the context in which MCC occur. I call for a meta-analysis of existent data to clarify effect size, heterogeneity, and possible publication bias.

The stilbene polyphenol trans-resveratrol has shown to interact with several mechanisms that may serve to preserve or even enhance cognitive function, either directly or indirectly. A small, but growing body of research has found resveratrol is capable of nitric oxide (NO)-mediated increases to cerebral blood flow (CBF), which, in turn, serve to increase access to the neural metabolic substrates (oxygen & glucose). To date, research has found increases in CBF and oxygen extraction resulting from oral resveratrol administration, yet these have not been found in conjunction with improved cognitive performance in young, healthy samples; questioning the CBF mechanism of resveratrol as an appropriate means to enhance cognitive performance. Additionally, it was hypothesized that the CBF effects of resveratrol may provide increased utility in naturally ageing populations, as such cohorts are noted to experience reductions to CBF and neural oxygen metabolism; which, in turn, is an acknowledged contributor of age-related cognition. To link the reduced neural oxygen availability suffered during ageing and subsequent poorer cognitive performance, the current thesis also aimed to test the use of hypoxia as a representative, experimental model for the cognitive ageing process. The purpose of this model was to provide clear and direct evidence that the CBF effects of resveratrol can function to attenuate reductions to cognition imposed via a compromised neural fuel supply. Therefore, the four acute, placebo-controlled, double-blind, crossover investigations of this thesis aimed to assess the efficacy of the resveratrol-mediated CBF effects to engender cognitive enhancement; in both young and older adults. The key findings from this thesis show that there is merit to a hypoxia model of cognitive ageing, evidenced by clear cognitive deficits that are also commonly observed with ageing cohorts. Furthermore, a single dose of resveratrol showed to increase fuel oxidation during cognitive performance when measured via indirect calorimetry. However, resveratrol was unable to provide increases to CBF (when measured by Near-Infrared Spectroscopy) or cognitive performance in hypoxia or in ageing populations. In fact, resveratrol was found to impair cognitive performance in the latter. The results of this thesis therefore do not support the argument that resveratrol can provide CBF-mediated cognitive enhancement in healthy, young or naturally ageing samples.

The acute stress response is an adaptive and necessary function which, when activated under appropriate conditions, promotes survival. However, studies have demonstrated that chronic over-activation of the systems that regulate the stress response leads to the dysregulation of the hormonal mediators, which can, subsequently, result in deleterious health outcomes. Whilst the psychobiological response to acute stressors has been explored extensively, literature assessing the anticipatory and recovery windows surrounding stressor exposure is currently in its infancy. It has been observed that the anticipatory period prior to exposure to a stressor can prolong the activation of the stress response; however less is known of the effects of delayed recovery following stress exposure. The present thesis addressed the question of whether anticipatory patterns differ between a naturalistic and laboratory stressor, by firstly developing an ecological and easily administered socially evaluative stressor paradigm, and using this stressor as a tool for a) assessing the psychobiological response to the novel stressor and b) assessing the anticipatory and recovery period following this stressor, through the collection of psychobiological data over four days (the day prior to exposure, the day of exposure, the day after and on a control day). A similar sampling protocol was applied to assess the anticipation period preceding a naturalistic stressor (skydiving). Individual differences, which may potentially exacerbate or buffer the negative effects of stress, were also explored within the context of these stressors. In addition to assessing anticipation of forthcoming stressful events, following recent suggestions that forthcoming positive activities may also elicit similar patterns of anticipatory responses, the current thesis also addressed the question of whether these anticipatory responses may represent a reaction to memory recall for an upcoming task, and not exclusively a response experienced prior to a stressful event. This was addressed by assessing the anticipatory period prior to the requirement to remember to complete a simple task in order to receive a reward. The findings indicate that the developed stressor successfully elicited a stress response, and was anticipated to be a forthcoming demanding situation. State anxiety was greater on the day of planned stressor exposure, as was stress and worry about the event. In the skydiving study, those who knew they would complete a skydive that day secreted greater levels of cortisol across the day compared to those who were unsure whether they would participate in a skydive or not, and those who knew for certain that they would not complete the skydive. The study assessing the psychobiological response to anticipation of a pleasant stimulus, however, revealed no significant effects. The exploration of a range of individual difference factors demonstrates the importance of appraisal of the event. That is, irrespective of the nature of the event, an individual’s perception of the event is an important determinant of psychological and biological responding. On the basis of the empirical findings of this thesis, it is concluded that both the laboratory and naturalistic stressors elicit some form of anticipatory response. This finding is in concordance with previous suggestions that the stress response can be observed prior to direct stressor exposure. Furthermore, exploration of the role of individual differences in the anticipation of novel events identified a number of characteristics which may serve to buffer or exacerbate the negative effects of prolonged stress on health outcomes. Finally, the findings from this thesis do not suggest that the anticipatory responses reported for stressors are extended to the anticipation of pleasant events, but that they may exclusively apply to stimuli perceived to be stressful and ultimately, a forthcoming demand. However, when individual differences are taken into account, it appears that the novelty of a forthcoming event in general may be more influential in appraisals of the event, rather than the nature of the task itself.

Self-medication of plant based foods and food extracts which have ostensible therapeutic benefits has considerably increased within non-clinical populations over the last two decades. The overarching reason for this rise in consumption is to improve health and cognitive performance. One such group of foods are flavonoid-rich berry fruits. In the literature, there has been a recent rise in evidence showing that the consumption of flavonoid-rich berries can modulate aspects of behaviour, especially memory, in animal models and in aged humans. Physiological parameters such as blood-flow and glucose levels; and biological mechanisms such as monoamine oxidase (MAO) activity and nitric oxide (NO) synthesis, which have the potential to impact human behaviour, are also shown to be manipulated by flavonoid compounds. The dark purple fruits of the blackcurrant (Ribes nigrum) are naturally high in flavonoids, however no literature assessing cognitive effects of their consumption is available. The main focus of this thesis was to assess the impact of standardised flavonoid-rich blackcurrant extracts upon cognitive performance and mood in healthy human participants. Two extracts were examined within the thesis, a freeze dried powder extract fortified to contain 30% anthocyanins (DelcyanTM) and a fresh from frozen cold pressed juice extract (Blackadder cultivar, Plant and Food Research Ltd). Utilising a series of randomised, between subjects, double bind studies, measures of memory, attention, executive function and psychomotor performance were implemented during the course of the thesis at various post-dose time points. Throughout the investigational chapters of the thesis, physiological parameters and potential mechanisms driving any behavioural changes were measured. Such measures included measures of central and peripheral haemodynamics, MAO inhibition, monoaminergic tone, prolactin secretion and post-prandial glucose profiles. Single doses of each of the blackcurrant extracts used in this thesis yielded positive results with effects of post-harvest extraction technique evident. Although no clear pattern of behavioural modulation was found after consumption of the blackcurrant extracts, there was some evidence to show increases in attention processes during cognitively demanding paradigms in young participants. No positive effects were evident upon any other cognitive paradigm. Physiological effects of acute blackcurrant supplementation included a modulation of post-prandial glucose profile and hemispheric dependent modulations of cerebral blood flow. Most strikingly, a pharmaceutical level inhibition of both monoamine oxidase isoforms and reductions in blood plasma prolactin were found. The findings of this thesis may have implications for enhancement of cognitive performance, attenuation in natural cognitive decline over the lifespan, and potentially, clinical applications in the treatment of neurological diseases.

Psychometric testing is widely used in the selection of employees. Many people also take psychometric tests in consultation with careers advisers for personal development purposes. This research examines the short-term negative reactions to the test and feedback process in terms of changes in Positive and Negative Affect and 'State' Self-Esteem. It has been suggested that in addition to the common sense assumption that individuals who perform badly on a test might be more inclined to react negatively to feedback, reactions might also be influenced by personality factors including Locus of Control and levels of Global Self-Esteem. In addition, there has been debate about the impact of feedback on the reactions of test takers to the test process. The results from a small scale pencil and paper based investigation are reported n56 and a much larger on-line investigation nr459. In both studies there were three levels of feedback: none, basic and detailed. Participants were identified as either having 'Internal' or 'External' Locus of Control and in the large study as 'Successful' or 'Failure' performers. Results from the small, initial study were inconclusive, but there was evidence in the main study that participants with an 'Internal' Locus of Control experienced more negative psychological effects than those with an 'External' Locus of Control. Specifically, the Internal Locus of Control group showed statistically a greater decline in State-Self-Esteem following the test and/or test and feedback process than their External counterparts. The level of detail in the feedback provided did not significantly affect the extent of any negative or positive psychological reactions, but Global Self-Esteem was confirmed as the factor which accounts for the largest portion of the variance in reactions. The implications for the use of psychometric testing in professional settings are discussed.

This thesis aims to provide an understanding of the perceived causes of Postnatal Depression (PND). Despite increasing research exploring the aetiology and risk factors for PND, to date, little research has explored how individuals perceive the causes of PND. The first part of this thesis reviews the literature on causal beliefs in adults in clinical, community and general population samples. Thirteen papers were critically appraised to reveal insights into these perceived causes. Beliefs were grouped into four emergent themes: (1) biological; (2) psychological; (3) social; and (4) cultural (including religious). The review identified a need to explore how PND is understood culturally, particularly amongst lay individuals from minority faith and ethnic groups. In accordance with these recommendations, the second part of this thesis is a Q-methodological study of the perceived causes of PND amongst British Muslim women of Arab origin. The sample comprised eleven participants recruited from a community organisation. Participants sorted 50 statements, each detailing a possible cause of PND, according to how much they believed them to be causes of PND. Findings identified two clear and distinct accounts: stress-generation and diathesis-stress, significant in causing PND. Although both accounts were clearly embedded in faith and values, the viewpoints operated with a subtly different interpretation of the role of faith in relation to PND. The third paper provides a reflective commentary on the research process, including a methodological critique of the research project and reflections on the personal impact of the research on the researcher. Contrary to the dominant biomedical model, the thesis highlights the existence of wide-ranging, multi-factorial explanatory models for PND. Eliciting and understanding these causal models can help to engage clients and provide culturally sensitive interventions.

This thesis consists of three chapters; the first is a literature review, Chapter Two is an empirical paper and the final paper is a reflective account of the research process. Chapter One details a review of the existing literature concerning Internet-based interventions for addressing eating and weight issues. An overview of the available programs and a methodological critique of the current research are provided. The findings are summarised in terms of clinical implications and recommendations for further exploration are given. The empirical paper in Chapter Two reports on a study examining the use of a podcast in informing young people about weight issues. An Internet-based podcast intervention was provided to participants aged 14-25 years, who had completed a set of questionnaires concerning weight concerns, social anxiety, mood, perfectionism, self-esteem and substance use. Post and follow-up data were also collected in order to examine any effects of the intervention. Results demonstrated that after listening to the podcast, participants demonstrated significant improvements on a number of the measures, most of which were maintained at follow-up. Significant differences were found between participants with high weight concerns and those with low weight concerns on a selection of measures. The discussion includes clinical implications and potential future research directions. The final chapter contains reflections on the research process, including; methodological considerations, personal considerations and future directions. Due to the personal nature of this account, it has been written in the first person narrative. All papers have been written in accordance with guidance for authors provided by The British Journal of Clinical Psychology (see Appendix 2).