Evaluating Faces on Trustworthiness After Minimal Time Exposure

Abstract

Previous studies have shown that trustworthiness judgments from facial appearance approximate general valence evaluation of faces (Oosterhof & Todorov, 2008) and are made after as little as 100 ms exposure to novel faces (Willis & Todorov, 2006). In Experiment 1, using better masking procedures and shorter exposures, we replicate the latter findings. In Experiment 2, we systematically manipulate the exposure to faces and show that a sigmoid function almost perfectly describes how judgments change as a function of time exposure. The agreement of these judgments with time-unconstrained judgments is above chance after 33 ms, improves with additional exposure, and does not improve with exposures longer than 167 ms. In Experiment 3, using a priming paradigm, we show that effects of face trustworthiness are detectable even when the faces are presented below the threshold of objective awareness as measured by a forced choice recognition test of the primes. The findings suggest that people automatically make valence/trustworthiness judgments from facial appearance.