Dr. Robert Rosenthal of Harvard University conducted this experiment in a San Francisco Bay area school:
At the beginning of the school year, the principal called three teachers into his office.
He said to the teachers, "As a result of your teaching excellence over past years, we’ve come to the conclusion that you are the best teachers in this school. As a special reward to you, we’ve identified three classes each with 30 of the brightest students in this school—the students with the highest IQ’s. We're going to assign them to you to teach for the entire year.
"Now, we don't want to be accused of discrimination, so it's very important that you don’t tell these children in any way that you know they've been selected for a screened class. And second of all, we're not going to tell their parents, because we don't want to cause any complications there. I expect you to teach exactly the same way you normally do, using exactly the same curriculum. And I expect you to get very good results with these students."
The results: At the end of the school year, these students led not only the school, but the entire school district in academic accomplishment.
Calling the three teachers into his office, the principal said, “Well, you've had a very good year."
"Yes, we have. It was so easy!" replied the teachers. "These children were so easy to teach. They were so eager to learn. It was such a pleasure to teach them."
"Well, maybe I'd better tell you the truth," said the school principal.
"This has been an experiment. These 90 children were chosen out of the school population at random. When I assigned them to your class at the beginning of the year, I had no idea what their IQ’s were at all."
"That's incredible!" exclaimed the teachers. "But how could it be that they scored so high? They did so well. They got such good grades. Ah hah! Yes! It must be because we are such excellent teachers."
At which the principal said, "And I think I should also tell you the other side of the experiment. At the beginning of the school year, we put all the teachers' names in a hat, and yours were the first three names that were drawn."
You can understand why these average students did so well if you understand the Tao of Positive Expectations: you achieve what you expect to achieve and what others expect you to achieve.