Experiments have shown that in behavioral research employing human or animal Ss, E’s expectancy
can be a significant determinant of S’s response (Rosenthal, 1964, in press). In studies
employing animals, for example, E’s led to believe that their rat Ss had been bred for superior
learning ability obtained performance superior to that obtained by Es led to believe their rats had
been bred for inferior learning ability (Rosenthal & Fode, 1963; Rosenthal & Lawson, 1964). The
present study was designed to extend the generality of this finding from Es to teachers and from
animal Ss to school children.