Gilly is an Evolutionary and Developmental Psychologist based at Birkbeck, University of London. She is the director of the Comparative Cognition Group investigating the behaviours and brain organisation of children, gorillas and chimpanzees focusing on how cognitive abilities evolve and develop over time and across species. She is a former Daphne Jackson Trust Research Fellow and the founder and director of the Me, Human project which regularly engages in public outreach and education and advocates for women and girls in science. Gilly is the Deputy Dean for the School of Science.