Historical research by Peter J. Snyder, Ph.D., reveals more of Charles Darwin’s thinking when he completed what may be the first example of a prospective "single-blind" study of human perception of emotional expression. Through scrutiny of Darwin's work, including previously unpublished handwritten notes on his experiments, Snyder explains how this early experiment has direct implications to current work today in the areas of schizophrenia, autism spectrum disorders and other neuropsychiatric conditions. Credit: Randy Beever, Lifespan