People automatically evaluate faces on multiple trait dimensions, and these evaluations predict important social outcomes, ranging from electoral success to sentencing decisions. Based on behavioral studies and computer modeling, we develop a 2D model of face evaluation. First, using a principal components analysis of trait judgments of emotionally neutral faces, we identify two orthogonal dimensions, valence and dominance, that are sufficient to describe face evaluation and show that these dimensions can be approximated by judgments of trustworthiness and dominance. Second, using a data-driven statistical model for face representation, we build and validate models for representing face trustworthiness and face dominance. Third, using these models, we show that, whereas valence evaluation is more sensitive to features resembling expressions signaling whether the person should be avoided or approached, dominance evaluation is more sensitive to features signaling physical strength/weakness. Fourth, we show that important social judgments, such as threat, can be reproduced as a function of the two orthogonal dimensions of valence and dominance. The findings suggest that face evaluation involves an overgeneralization of adaptive mechanisms for inferring harmful intentions and the ability to cause harm and can account for rapid, yet not necessarily accurate, judgments from faces.emotions ͉ face perception ͉ social cognition T he belief that the nature of the mind and personality could be inferred from facial appearance has persisted over the centuries. References to this belief can be dated back to ancient Greece, Rome, and China (1). In the 19th century, the pseudoscience of physiognomy reached its apogee. Cesare Lombroso, the founder of criminal anthropology, argued that ''each type of crime is committed by men with particular physiognomic characteristics''. For example, ''thieves are notable for their expressive faces and manual dexterity, small wandering eyes that are often oblique in form, thick and close eyebrows, distorted or squashed noses, thin beards and hair, and sloping foreheads'' (2). Lombroso provided his ''scientific'' testimony at several criminal trials.Although modern science, if not folk psychology (3), has largely discarded such notions, trait evaluations from faces predict important social outcomes ranging from electoral success (4-6) to sentencing decisions (7,8). Studies show that people rapidly evaluate faces on multiple trait dimensions such as trustworthiness and aggressiveness (9, 10). For example, trait judgments can be formed after as little as 38-ms exposure to an emotionally neutral face (10). Studies also show that the amygdala, a subcortical brain region critical for fear conditioning and consolidation of emotional memories (11), plays a key role in the assessment of face trustworthiness (12-15).Why do mechanisms for rapid spontaneous face evaluation exist if they do not necessarily deliver accurate inferences? This apparent puzzle from an evolutionary point of view can be resolved b...