Why, how and when does mood influence positive testing, that is, the selection of matching questions, when people actively search for information about others they meet? In four experiments, we demonstrated that happy mood increased positive testing compared to sad mood. Experiment 1 showed that happy participants were more strongly motivated to get along and smooth the interaction to come than sad ones. In addition, evidence was provided by a mediation analysis that happy mood increased the preference for positive testing because of such an improved motivation to get along. Furthermore, Experiment 2 showed that happy participants' preference for positive testing vanished when cognitive resources were limited. The preference for positive testing appeared under happy mood only when the context made salient the goal to get along (Experiments 3 and 4). Together, these results suggest that positive testing in a social-hypothesis testing paradigm may have social values. Copyright © 2009 John Wiley & Sons, Ltd.