Across borders and time : testing the competing perspectives of system justification : a thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Psychology at Massey University, Albany, New Zealand

Abstract

Why do people defend societal systems that perpetuate inequality and injustice? This question is increasingly relevant in today’s geopolitical climate, amid growing tensions between calls for progressive social change and maintenance of a traditional, sometimes polarized, status quo. System Justification Theory (SJT) posits that individuals are motivated—due to both dispositional and situational factors—to defend and justify existing social, economic, and political systems, even when doing so may conflict with their self- or group-interests. Competing theories, however, argue that system justification is largely a reflection of those interests. This thesis tests these competing perspectives on system justification across countries and time through four studies, using a consistent four-item measure of general system justification for comparability.

Study 1 examined SJT’s status-legitimacy hypothesis in China and the United States, using both subjective and objective indicators of socioeconomic status (SES). Subjective SES consistently positively predicted system justification across cultures and time, aligning with self- and group-interest explanations. Objective SES, however, showed only weak and inconsistent support for SJT in China. Study 2 expanded the scope cross-culturally, comparing SJT to the social identity perspectives and Social Dominance Theory, using data from 42 countries. Results largely favored self- and group-interest explanations over SJT across cultures. Study 3 tested SJT’s claim that system justification provides psychological benefits in the form of enhanced psychological wellbeing using four waves of longitudinal data. Bidirectional cross-lagged panel modeling showed that system justification predicted greater subjective SES via increased life satisfaction over time, but not vice versa, supporting SJT’s claim that system-justifying beliefs can confer psychological benefits independent of materials self-interest. However, when assessing this model using more robust longitudinal techniques, no such effect was observed. Study 4 used a longitudinal quasi-experiment centered around New Zealand’s 2023 general election to compare SJT with the Social Identity Model of System Attitudes (SIMSA). Results showed that system justification generally coincided with self- and group-interests among electoral winners and losers in line with SIMSA. However, among disadvantaged electoral losers, perceived system threat [of SJT] better explained continued system justification than did optimism about the future [of SIMSA], providing stronger support for SJT.

Overall, this thesis demonstrates that system justification arises from a complex interplay of individual, situational, ideological, and societal factors. While system justification often reflects self- and group-interests, under certain conditions it functions as an ideological mechanism that can conflict with these very interests to uphold societal structures – especially when those structures are perceived to be under threat. This supports the view of system justification as both an ideological disposition and a palliative mechanism, sustaining societal structures despite inequality. Such insights highlight the challenge of addressing systemic injustice and underscore the need to frame social change in ways that align with psychological motivation and a desire for stability.