Conscientiousness, Health and Longevity: Exploring explanatory mechanisms

Conscientiousness is positively associated with health and longevity. Evidence has suggested that conscientiousness can influence health via engagement in health behaviours. More recently, research has focussed upon alternative pathways through which conscientiousness may convey its desirable effects. Questionnaire methods were utilised to examine the association between conscientiousness and health behaviours (study 1). Behavioural intention was explored as a mediator of the conscientiousness–fruit and vegetable consumption relationship, with results indicating that behavioural intention fully mediated the relationship. Conscientiousness was also shown to predict health behaviour guideline adherence, when health behaviours were examined independently and simultaneously (study 2). Findings indicated greater levels of adherence in individuals high in conscientiousness. Factor analysis revealed that the items employed to measure the facets of industriousness, order, self-control, virtue and traditionalism are reliable and represent separate lower order facets of conscientiousness. Meanwhile, the items employed to measure the facet of responsibility require revision. Study 3 assessed psychological and physiological reactivity in response to stress in individuals with different levels of conscientiousness. Differential effects were seen between the conscientiousness groups, and primary appraisals were identified as being important for dealing with anticipated stress physiologically. Daily diaries and multi-level modelling were employed to assess the effects of daily hassles on unhealthy between-meal snacking in individuals high and low in conscientiousness (study 4). An implementation intention based intervention was also delivered, and experimental condition and conscientiousness were assessed as moderators of the daily hassle–unhealthy snacking association. Conscientiousness was shown to moderate the relationship with a greater association seen between daily hassles and unhealthy snacking in individuals low in conscientiousness. Condition also moderated this relationship, with individuals assigned to the active control condition consuming fewer unhealthy snacks on more stressful days. This thesis has provided evidence to support the roles of behavioural intention and stress in the conscientiousness-health association, and has highlighted multiple relations between these factors