Social Judgment Theory and Working Assets®Displacement and attitude change, which involve assimilation and contrast, are not to be confused. Positive attitude change refers to a person's change in the direction of the communication. Negative attitude change, sometimes called the boomerang effect, is said to occur when a person changes away from a position advocated rather than toward it.
Mary T. Flores, University of Arizona
http://www.ic.arizona.edu/~comm300/mary/interpersonal/SJ_Utne.6.html