Two groups of graduate students were given rats and instructed to teach the rats how to run mazes. Group 1 was told that they had "very smart" rats that should learn quickly. Group 2 was told that they had "very stupid" rats that should learn slowly. In actuality, neither group was any different, and the rats were randomly assigned. In spite of that, when the experiment concluded, the rats taught by Group 1 had learned the maze much more quickly. How can that be explained?
A) experimenter effect
B) placebo effect
C) subject bias
D) treatment effect

Question

Quizplus · Accepted Answer

The difference in the rats' performances can be explained by the experimenter effect, which refers to the unintentional influence that an experimenter's expectations or biases can have on the outcome of an experiment. Group 1 may have inadvertently given the rats more positive reinforcement or encouragement, while Group 2 may have unknowingly given their rats less attention or motivation due to their perceived lower intelligence.

Two Groups of Graduate Students Were Given Rats and Instructed