Dwyer, Patrick C.2015-11-022015-11-022015-08https://hdl.handle.net/11299/175125University of Minnesota PhD dissertation. August 2015. Major: Psychology. Advisors: Mark Snyder and Alexander Rothman. 1 computer file (PDF): vii, 127 pages.Most of the research examining the influence of gratitude expressions on compliance has focused on their benefits, but some empirical and anecdotal evidence suggests that they can both facilitate and inhibit compliance with requests. This dissertation seeks to understand when and why gratitude expressions enhance compliance and also when and why they may lead to diminished compliance. Two online experiments of adult participants tested hypotheses based on self-determination theory and the persuasion knowledge model. Motivation type and persuasion awareness were hypothesized to moderate the influence of gratitude expressions on compliance, and perceptions of sincerity, basic need support, and differences in state motivation were hypothesized to mediate these effects. Results suggest that gratitude expressions increase compliance through affecting perceptions of sincerity and by supporting relatedness needs. However, results also suggest that gratitude expressions do not always enhance compliance, and can sometimes lead to diminished compliance. Motivation type and persuasion awareness were both found to moderate the influence of gratitude expressions on compliance, and these effects were mediated by differences in state motivation. This research broadens our understanding of gratitude in social contexts by showing that expressions of gratitude can not only facilitate compliance with requests, but also sometimes lead to reductions in compliance. It demonstrates when each of these outcomes is more likely to occur, and it also contributes by uncovering some of the psychological dynamics underlying these influences.enSocial psychologyEmotionGratitudeMotivationPersuasionSocial influenceSocial psychologyThesis or Dissertation