People see what they believe, not vice versa, when it comes to social injustice.

And this mind-altering trick of perception keeps moral outrage at bay, especially among the rich, a new psychological study suggests.

By reducing outrage, this mental hoodwink also impedes social change because it inhibits people from taking action, allowing injustices to persist, said lead researcher Cheryl Wakslak of New York University.

Research has shown that people become emotionally distressed when confronted with inequality. The privileged minority is particularly affected, and they are likely to have a nagging worry that their cash and prizes are undeserved.

To keep a clean conscience and legitimize privilege, individuals often alter their perceptions of the status quo.

The details of how that mental distortion provides the relief, however, remained a mystery until now.

Mind benders

To get at those details, Wakslak and her colleagues presented survey questions and scenarios involving just and unjust situations to about 100 undergraduate students.

Participants read brief statements that involved inequality and injustice, after which they reported the emotional distress they felt.

Participants who opposed additional equality measures felt less emotional distress - focused both outward (anger and sympathy) and inward (sadness and guilt). The scientists defined moral outrage as outward-focused distress.

Sunshine state of mind

In another experiment, the team divided high-income individuals into two groups. One group read rags-to-riches stories, which painted rosy, unrealistic images of the world. The other half read essays about innocent victims, which highlighted the unfairness of the judicial system.

In post-reading questionnaires, participants who had read the heroic stories showed less moral outrage and reported better moods than the subjects exposed to the innocent-victim narratives.

They also found a link between the level of moral outrage and willingness to support community-service programs. When outrage was dampened, subjects were less likely to endorse initiatives aimed at boosting social equality.

"We assume that people care about justice, at least to some degree, and are bothered by potential departures from fairness," the scientists wrote in a report of their work published in the current issue of the journal Psychological Science. "In order to maintain their perceptions of the world as just, however, people do not necessarily strive to make changes that will increase the overall amount of fairness and equality in the system."