...about anything, really.
http://www.psych.umn.edu/courses/spring07/borgidae/psy5202/readings/lord,%20ross%20&%20lepper%20(1979).pdf
Biased Assimilation and Attitude Polarization: The Effects of Prior Theories on Subsequently Considered Evidence
Charles G. Lord, Lee Ross, a n d Mark R. Lepper
Stanford University