Experimenter Expectancy Effect On Children in a Classroom Setting Rosenthal and Jacobson (1966) sought to test the experimenter expectancy effect by examining how much of an outcome teachers' expectancies could have on a group of children. Earlier investigations in this area were also conducted by Rosenthal (1963). He worked with children in a research lab, giving each one a rat and telling them it was either bred for intelligence or for dullness. The children were put in charge of teaching the rats how to learn mazes. Rosenthal's results showed that the rats that were believed by the students to be smart, were able to learn the mazes mu