The functional basis of face evaluation explores how people automatically assess faces on multiple trait dimensions, such as trustworthiness and dominance, which predict important social outcomes. Using behavioral studies and computer modeling, the authors developed a 2D model of face evaluation based on two orthogonal dimensions: valence (positive/negative) and dominance (strong/weak). These dimensions were identified through principal components analysis of trait judgments of emotionally neutral faces. Valence evaluation is sensitive to facial cues resembling expressions signaling whether to approach or avoid someone, while dominance evaluation is sensitive to cues signaling physical strength or weakness. The findings suggest that face evaluation involves overgeneralization of adaptive mechanisms for inferring harmful intentions and the ability to cause harm, leading to rapid but not necessarily accurate judgments. The model was validated using data-driven statistical models for face representation and showed that important social judgments, such as threat, can be reproduced based on these dimensions. The study also revealed that facial cues related to physical strength and maturity are more influential in dominance evaluation than in valence evaluation. The results highlight the importance of facial features in social cognition and provide a framework for understanding how faces are evaluated in terms of their perceived traits. The findings have implications for understanding social judgments and the role of facial appearance in human behavior.The functional basis of face evaluation explores how people automatically assess faces on multiple trait dimensions, such as trustworthiness and dominance, which predict important social outcomes. Using behavioral studies and computer modeling, the authors developed a 2D model of face evaluation based on two orthogonal dimensions: valence (positive/negative) and dominance (strong/weak). These dimensions were identified through principal components analysis of trait judgments of emotionally neutral faces. Valence evaluation is sensitive to facial cues resembling expressions signaling whether to approach or avoid someone, while dominance evaluation is sensitive to cues signaling physical strength or weakness. The findings suggest that face evaluation involves overgeneralization of adaptive mechanisms for inferring harmful intentions and the ability to cause harm, leading to rapid but not necessarily accurate judgments. The model was validated using data-driven statistical models for face representation and showed that important social judgments, such as threat, can be reproduced based on these dimensions. The study also revealed that facial cues related to physical strength and maturity are more influential in dominance evaluation than in valence evaluation. The results highlight the importance of facial features in social cognition and provide a framework for understanding how faces are evaluated in terms of their perceived traits. The findings have implications for understanding social judgments and the role of facial appearance in human behavior.