Trait procrastination undermines outcome and efficacy expectancies for achieving health-related possible selves.

People often fail at following through with their health behaviour goals. How health goals are cognitively represented holds promise for understanding successful health behaviour change. Health-related possible selves (HPS) reflect cognitive representations of a future self that people may wish to achieve (hoped-for-HPS) or avoid (feared-HPS), that can promote health behaviour change. However, success depends on the strength of the efficacy and outcome expectancies for achieving/avoiding the HPS. Personality traits linked to poor self-regulation are often not considered when assessing the potential self-regulatory functions of HPS. The current study addressed this issue by examining the associations of trait procrastination with efficacy and outcome expectancies for hoped-for-HPS and feared-HPS, and health behaviour change intentions and motivations in a community sample (N = 191) intending to make healthy changes in the next 6 months. Trait procrastination was associated with weaker intentions and motivations for health behaviour change, and lower efficacy and outcome expectancies for hoped-for-HPS, but not feared-HPS. Bootstrapped multiple mediation analysis found significant indirect effects of procrastination on health behaviour intentions, through outcome, but not efficacy, expectancies for hoped-for-HPS. Results suggest that issues in imagining a hoped-for-HPS can be achieved are linked to weak intentions for health behaviour change for those with chronic self-regulation difficulties. Research into interventions that strengthen feeling connected to hoped-for-HPS is recommended.