She completed her B.Sc. at the University of Toronto in 1997 and her Ph.D. at the University of Chicago in 2002. Following a post-doctoral fellowship, she took her first faculty position in 2003. In 2007, Sommerville was named a Kavli Foundation Fellow. Her research focuses on the origins of social cognition in infancy and early childhood. Sommerville currently receives funding from the National Institute of Child Health and Development and the John Templeton Foundation.