Our work at the Rutherford Lab is experimental psychology motivated by evolutionary theory. What are the psychological adaptations shared by all humans that solve the adaptive problems of our ancestral environment? Specifically, we work on the questions of Social Perception and Social Perceptual Development. We study animacy perception, because discriminating what in the world is animate is the first developmental step in social cognition. We study face perception and the perception of emotional facial expressions, and we are exploring the development of categorical perception of emotional expressions. Once we know what social perceptual skills develop in the first years of life, we can develop tests for atypical development. Using eye tracking technology, we are finding very early markers of autism spectrum disorders, including how infants at risk for autism use motion information in animacy perception, the perception of faces, and the perception of emotional facial expressions, and how infants use facial eye gaze to capture attention.