Abstract: Non-social pattern-deviancy aversion refers to negative emotional reactions to stimuli violating regular patterns, whereas social-deviancy aversion denotes negative attitudes toward minority groups. Three experiments investigated how non-social pattern-deviancy aversion influences prejudice against homosexuality and its underlying mechanisms. Study 1 established a significant positive correlation between non-social pattern-deviancy aversion and social-deviancy aversion. Study 2 manipulated non-social pattern deviancy aversion and demonstrated its causal impact on homosexual prejudice, with social-deviancy aversion mediating this relationship. Study 3 revealed that the predictive effect of non-social pattern deviancy aversion on prejudice was moderated by group size, such that stronger prejudice emerged when homosexuals were categorized as a numerical minority. These findings collectively demonstrated that nonsocial pattern-deviancy aversion exacerbates discrimination by activating intergroup bias toward minority
groups, particularly under minority-group contexts. This research enhances understanding of cognitive mechanisms underlying prejudice and informs theoretical frameworks for bias reduction interventions.

Key words: prejudice against homosexuals, group bias, nonsocial pattern deviancy aversion, social deviancy aversion, group-size