APA Dictionary of Psychology

a theory of attitude change postulating that the magnitude of persuasion produced by a particular message depends on how much the position advocated in the message differs from a person’s attitude. Persuasion is likely to be greatest when a message advocates a position that a person finds neither clearly acceptable nor clearly objectionable. See also latitude of acceptance; latitude of noncommitment; latitude of rejection. [attributed to U.S. psychologists Carolyn Wood Sherif (1922–1982), Muzafer Sherif, and Carl I. Hovland]