Rosalie Alberta Rayner (September 25, 1898 – June 18, 1935) was an undergraduate psychology student, then research assistant (and later wife) of Johns Hopkins University psychology professor John B. Watson, with whom she carried out the study of a baby later known as "Little Albert." In the 1920s, she published essays and co-authored articles and a book with Watson about child development and familial bonds. Rayner was born in Baltimore, Maryland, on September 25, 1898. Her father and grandfather, Albert William Rayner and William Solomon Rayner, respectively, were successful businessmen. Her mother, Rebecca Selner Rayner, and father had one other daughter, Evelyn. Albert William Rayner made a living dealing with railroads, mining, and shipbuilding. The Rayner family also supported Johns Hopkins University, to which they contributed $10,000 toward research. Rayner's uncle, Isidor Rayner, was also a prominent public figure. Isidor worked as a senator in Maryland and managed public inquiries into the sinking of the Titanic, in addition to serving as Attorney General of Maryland for four years. Rosalie Rayner continued her education at Vassar College in New York, where she graduated with a Bachelor of Arts degree in 1919. At Vassar, she was a classmate of Mary Cover Jones, who became a prominent psychologist with a focus on lifetime development. Upon graduation, Rayner enrolled at Johns Hopkins University but failed to take any classes. She was hired as an assistant to John B. Watson, who is best known for pioneering the approach to behaviorism. Behaviorism is a term that Watson introduced into the field of psychology to describe the goal of predicting and controlling observable behaviors. Rayner and Watson aimed to make family life reflect an empirical environment, based on the belief that behaviors were not hardwired at birth, but instead were acquired through conditioning. Rayner and Watson claimed to have studied over 500 children, with the Little Albert experiment being their only attempt at a psychological experiment (it would not be categorised as an experiment today).