<p>Research within the psychology of religion has illustrated the importance of both religious belief and religious belonging for facilitating cooperative behaviour. Specifically, the supernatural punishment hypothesis (Johnson, 2016; Johnson & Krüger, 2004) and identity fusion (Swann et al., 2009; Whitehouse, 2018) discuss belief and belonging, respectively. This thesis examines the connection of these two areas, with a focus on the understudied religious concept of karma. In Study 1, 193 participants took part in an online questionnaire, with a five-condition between subjects design, that investigated the content of religious belief by using karma and god related religious priming stimuli (images and vignettes) to influence individual’s belief. None of the four experimental conditions were found to change responses on belief in supernatural agents or karma. Belief in god/karma was associated with endorsement of both a punitive and benevolent god/karma. However, when both endorsements were included in the model, only benevolent endorsement was significant. In Study 2, 402 participants took part in a three-condition mixed-methods design with six repeated trials of a voluntary contribution task, which investigated how karma and god related religious priming stimuli (vignettes) influenced cooperative behaviour. Mixed methods analysis revealed that those in the karma condition had higher cooperative tendencies than those in the neutral condition, but did not differ from the god condition. Belief in supernatural agents did not affect how individuals were affected by the god condition. However, those with higher belief in supernatural agents and higher identity fusion were the least cooperative within the karma condition. Contrary to what was predicted, increased belief in karma predicted un-cooperative behaviour in the karma condition. These and other important findings are discussed with focus on the New Zealand context and how the findings from this thesis contributes to the supernatural punishment and identity fusion literature, by highlighting implications, limitations, and areas of focus for future research.</p>