Susan Goldin-Meadow is the Beardsley Ruml Distinguished Service Professor in the Departments of Psychology and Comparative Human Development, and the Committee on Education at the University of Chicago. She received her Ph.D. from the University of Pennsylvania, where she worked with Rochel Gelman and Lila Gleitman. Her research is two-pronged: (1) The home-made gestures, called homesign, that profoundly deaf children create when not exposed to sign language. Homesign offers us insight into the skills that children themselves bring to language learning, and into the linguistic properties that conventional sign languages are likely to have had at the earliest stages of their creation. (2) The gestures hearing speakers around the globe spontaneously produce when they talk. These co-speech gestures provide insight into how we talk and think.