According to cognitive-experiential self-theory (CEST), individuals have 2 systems for processing information, a rational system and an experiential system. Research conducted under norm theory (NT) has provided impressive evidence of an if only (IO) effect associated with postoutcome processing of aversive events that are highly consistent with formulations in CEST. Two studies involving vignettes adapted from NT were conducted that tested 4 hypotheses and corollaries derived from CEST. It was demonstrated, in support of hypotheses, that the IO effect can be obtained with ratings of one's own and of a protagonist's specific behaviors, as well as with ratings of a protagonist's diffuse emotions (the usual procedure); that a rational orientation decreases the IO effect; that increasing the intensity of outcomes increases it; and that priming the experiential system reduces people's ability to subsequently think rationally. The theoretical and research implications of these findings are discussed.