People often have to judge the social motives of others, for example, to distinguish truly prosocial people from those merely trying to appear prosocial. Gaze can reveal the motives underlying social decisions, as decision-makers dedicate more attention to motive-relevant information. So far, eye-tracking has mainly been used as a passive tool for the researcher; in contrast, we also provide (real -time) eye-tracking information to the participants. We extend the use of eye -tracking and apply it as a communication device to study social signaling. We find that untrained observers can judge the prosociality of decision -makers from their eye-tracked gaze alone, but only if there are no strategic incentives to appear prosocial. When gaze is strategic because decisionmakers have an incentive to appear prosocial, the cues of prosociality are invalidated, as both individualistic and prosocial decision -makers put effort into appearing more prosocial. Overall, we find th at gaze carries information about a person's prosociality, but also that gaze is malleable and affected by strategic considerations.