The psychologist Robert Rosenthal told student researchers that some rats in a study would learn a task quickly and others would learn the task slowly. In reality, there was no difference in the rats’ ability to learn the task. When the students tested the rats, the animals’ learning matched what the students were told. These results reflect:______.
a. the Hawthorne effect
b. the directionality problem
c. the experimenter expectancy effect
d. the third variable problem