In a Classic Experiment,psychology Students Were Assigned to Work Either

Multiple Choice

In a classic experiment,psychology students were assigned to work either with "bright" rats or with "dull" rats,described as such by the experimenter.After a series of tests,the students' results showed that the "bright" rats had outperformed the "dull" rats.However,in fact,all the rats were of the same strain and breed;there were no preexisting differences between the groups.What caused the difference in their performance?

A) By chance,the rats in one group actually were brighter than those in the other group.
B) Demand characteristics in the experiment cued the rats about how to perform in the mazes.
C) The students' expectations about the rats' performance influenced their observations and behaviours.
D) The students looked at average scores,rather than at each rat's individual score.