<p>Mindfulness is defined as a fundamental way of being, a way of relating to all of one‟s experiences whether positive, negative, or neutral, with an attentive, curious, and nonevaluative mindset (Kabat-Zinn, 2003; Williams, Teasdale, Segal, & Kabat-Zinn, 2007). The basic premise underlying mindfulness is that accepting moment-to-moment experiences as they arise, with an open-minded disposition, helps protect against psychological symptoms such as anxiety, depression, stress, and adverse ruminative thoughts (Baer, 2003; Hofmann, Sawyer, Witt, & Oh, 2010). In addition, mindfulness is also thought to enhance psychological health and wellbeing, such as increases in emotional intelligence, body image, and positive mental health (Bohlmeijer, ten Klooster, Fledderus, Veehof, & Baer, 2011; Stewart, 2004). Extant mindfulness literature has largely focused on the outcomes that are associated with mindfulness-based interventions designed to enhance an individual‟s state of mindfulness, though, less is known about naturally occurring dispositional mindfulness. According to some researchers, mindfulness manifesting as a trait (or individual difference characteristic) is an inherent human capacity that varies between individuals (Brown & Ryan, 2003; Kabat-Zinn, 1990). To examine the complexities of trait mindfulness, it is necessary to have a comprehensive understanding of the operationalisation of the construct. To date, however, methods for assessing mindfulness have received little attention in psychological research (Baer, Smith, Hopkins, Krietemeyer, & Toney, 2006). Across a series of three empirical studies (Chapters 2 through 4), this thesis aimed to explore the naturally occurring construct of trait mindfulness using two measures designed to capture this multifaceted phenomenon – the Five-Facet Mindfulness Questionnaire (FFMQ; Baer et al., 2006) and the Trait Toronto Mindfulness Scale (Trait TMS; Davis, Lau, & Cairns, 2009). Study 1 (Chapter 2) began with a psychometric analysis of the FFMQ, and then explored how the tendency to be mindful related to both positive and negative psychological outcomes. Contrary to expectations, a confirmatory factor analysis of the FFMQ in this sample yielded a 2-factor model of mindfulness (Nonjudging Awareness and Describing) as opposed to the five factors proposed by Baer et al. (2006). Further analyses revealed that the factor of Nonjudging Awareness appeared to be the most potent aspect of mindfulness that positively predicted happiness, life satisfaction, and adaptive coping (positive psychological outcomes) and negatively predicted depression, anxiety, and maladaptive coping (negative psychological outcomes). In Study 2 (Chapter 3), both the FFMQ and the Trait TMS were compared and tested for factor structure across three points in time on a community sample of individuals (N = 319). Both measurement invariance and convergent validity were explored, with results supporting expectations. First, results yielded a 5-factor structure of the FFMQ and a 2-factor structure of the Trait TMS. Second, factorial invariance on both mindfulness measures was evidenced across three time points. Third, results indicated moderate construct overlap between these two trait measures of mindfulness, i.e., they tapped a similar construct, as was expected. Study 3 (Chapter 4) sought to extend on the previous two studies‟ findings by 1) exploring whether trait mindfulness was positively predictive of positive psychological outcomes and negatively predictive of negative outcomes across time, and 2) comparing the psychological functioning of two groups – individuals with and without meditation experience – across time. Using the same sample from Study 2, trait mindfulness, as measured by the FFMQ and Trait TMS, supported hypotheses, though some predicted findings appeared to be manifested between the second and third time points only. Moreover, results indicated that meditation experience may protect against maladaptive psychological outcomes such as depression and anxiety, while increasing feelings of subjective happiness and life satisfaction (supporting traditional meditation ideology and current empirical literature). In combination, the present research supports and contributes novel perspectives to the existing body of mindfulness literature by suggesting that establishing ways to amplify the naturally occurring trait of mindfulness, although challenging, will prove fertile within Western clinical psychology, which looks to influence an individual‟s psychological wellbeing. Chapter 5 concludes this thesis with a discussion of the implications of the combined series of studies. Strengths and limitations of this research were considered, and future directions were proposed.</p>
How Well do Covariates Perform When Adjusting for Sampling Bias in COVID-19 Research? Insights from Multiverse Analyses
