We examined the process of becoming suspicious and discovering ulterior motives. Participants read about a likable behavior, then sequentially received ten cues about potential ulterior motives of the actor. Participants were asked to think aloud while they were reading. Their thoughts were coded. We expected that the general impression of the actor would gradually become more negative, whereas suspicion would first increase and later decrease, concomitant with increased certainty that ulterior motives were indeed involved. Confirming our hypotheses, we found a linear effect for general impression and a quadratic effect for suspicion. Discussion focuses on the development of suspicion as a process and on the relevance of our findings to other settings in which multiple hypotheses are entertained.There is ample evidence that most people cannot distinguish honest from deceptive behavior of others (Anderson, DePaulo, Ansfield, Tickle, & Green, 1999;DePaulo & Friedman, 1998;Ekman & O'Sullivan, 1991;Malone & DePaulo, 2001). One of the reasons why people are so poor at detecting deception is a pervasive truthfulness bias: People tend to accept everything they see at face value. Gilbert, Tafarodi, and Malone (1993) proposed that people cannot comprehend something without accepting it as true (cf. Gilbert, 1991). People do have the power to assent, reject, and to suspend their judgment, but only after they have initially believed the information to which they have been exposed.
242Social Cognition, Vol. 23, No. 3, 2005, pp. 242-256 This research was supported by NWO grant 575-12.030/1. We would like to thank Steven Fein and Laurie Rudman for their helpful comments and suggestions.