Concerns over students engaging in various forms of academic misconduct persist, especially with the post-COVID-19 rise in online learning and assessment. Research has demonstrated a clear role of the personality trait psychopathy in cheating, yet little is known about why this relationship exists. Building on the research by Curtis et al. ("Personality and Individual Differences," 185, 111277, 2022a), this study tested an extended Theory of Reasoned Action (TRA) model, including psychopathy as a precursor to attitudes and subjective norms, and measures of anticipated moral emotions (shame and guilt), to predict cheating intentions and cheating behaviours. A cross-sectional survey was administered online to university students from around the globe (n = 257). Results from a serial mediation analysis revealed that psychopathy predicted academic misconduct behaviours indirectly through attitudes, subjective norms, anticipated guilt (but not anticipated shame), and intentions. These findings indicate that cheating may be reduced by modifying attitudes to cheating, subjective norms regarding cheating, and anticipated feelings of guilt related to engaging in academic misconduct. In addition, the results revealed high rates of several forms of cheating, particularly in unsupervised online tests, which have been used more widely since the COVID-19 pandemic. This finding raises concerns regarding the poor security of such assessments.