To investigate the existence of an autonomous system justification motive that guides human behavior, we tested the dissonance-inspired strong system justification thesis: that the cognitive effort expended to justify societal systems on which people depend, is greater amongst the disadvantaged than amongst the advantaged when their group identities are weak in salience/strength. Using a novel pupil dilation paradigm to tap cognitive effort, we exposed an ethnic minority group (N-total = 263) to depictions of their ingroup as disadvantaged or advantaged after they had stated four things they liked about their ethnic group (strong group identity salience) or grandmother (weak group identity salience). We then measured fluctuations in their pupil diameter as they contemplated support for societal systems that were either relevant (high dependency) or irrelevant (low dependency) to their ethnic group. Results revealed that pupil sizes were larger in the group disadvantage condition than in the group advantage condition-indicating greater cognitive effort-but only when group identity was salient (Experiment 1) or when group identification was strong (Experiment 2). These effects occurred only for high dependency systems. Combined, this evidence contradicts the system-justification thesis, and questions the existence of an autonomous system justification motivation in humans.