After completing a PhD at the University of Cambridge, Riva Joyti Riley returned to the USA for the President’s Postdoctoral Fellowship program at the University of Maryland. Her research and teaching are focused on social behavior and its consequences for individuals and groups. She is especially interested in how individuals can use their own social influence to change their social environment, and how social influences impact social evolution. Evolution, which is often described as survival of the fittest, has so often produced incredibly cooperative species, and so she studies a delightful little fish, Cory catfish, to help understand how social influences can modify evolution and ecology and lead to complex social behaviors (as happened in humans).