Effects of evidence on attitudes: Is polarization the norm?

A 1979 study by Lord, Ross, and Lepper has been widely cited as showing that examination of mixed evidence on a topic leads to polarization of attitudes. The polarization phenomenon, we suggest, in fact encompasses two distinct change patterns-a shift from an initially moderate to a more extreme position (regarded here as genuine polarization) and a shift from an initially neutral to a moderate position (which might better be termed ''articulating a position''). The findings reported here indicate that genuine polarization is a real but infrequent outcome of exposure to mixed evidence. In addition, we offer data in support of the view that the effective component of such interventions is simply cognitive engagement, rather than exposure to new evidence.