In 1968, following the murder of civil rights leader Martin Luther King, teacher Jane Elliott tried discussing issues of discrimination, racism, and prejudice with her third grade class in Riceville, Iowa.

Not feeling that the discussion was getting through to her class, who did not normally interact with minorities in their rural town, Ms. Elliott began a two-day "blue eyes/brown eyes" exercise to reinforce the unfairness of discrimination and racism: Students with blue eyes were given preferential treatment, given positive reinforcement, and made to feel superior over those with brown eyes for one day; the procedure was reversed the next day, with Ms. Elliott giving favourable preference to brown-eyed students.

As a result, whichever group was favoured by Elliott performed enthusiastically in class, answered questions quickly and accurately, and performed better in tests; those who were discriminated against felt more downcast, were hesitant and uncertain in their answers, and performed poorly in tests.