The source effect: person descriptions by self versus others have differential effects on impression formation.

Self-presentation via favorable self-descriptions may not lead to the desired impression, whereas positive descriptions by others may be more effective because they seem less susceptible to motivated bias. In four experiments, we investigated whether person descriptions have more impact on impressions when provided by third parties than by targets themselves. Results showed that target impressions were consistently more in line with the target description when positive sociability-related or positive competency-related information was given by a third party than by the target. This source effect always occurred for ratings of claimed traits. In addition, ratings of the target's sociability were also affected when the claim was about competency. Source effects were not obtained for negative self-descriptions. The results are discussed in terms of the presumed underlying process on the basis of mediation data.