You Get What You Expect

by Site Author

You give an undergrad two lab rats. You tell him that one lab rat is a rat prodigy, capable of racing through a maze faster than any other rat. You tell him that the other lab rat is just an ordinary rat. The undergrad then times how long it takes each rat to make it through a maze. He is not at all surprised when the prodigy finishes an average of 1.12 minutes faster than the other rat.

But—here’s the kicker—the lab rat you labeled a genius was randomly assigned that label. It could have just as easily been the other rat. And yet, when you repeat the experiment over and over, the lab rat you randomly label as faster always finishes first.

Did the lab rat overhear you call it a genius? Did the label boost its little lab-rat self esteem? Not quite. What happened is that the undergrad treated the genius lab rat more carefully: he gently cradled the lab rat in his hands; he took care not to startle it; he stroked its little lab-rat head. Those little gestures soothed the lab rat, and soothed lab rats make for faster lab rats.

This is the 1963 Rosenthal-Fode experiment, which proved the existence of “experimenter-expectancy effects.” When you expect a lab rat to be bright, you treat it differently, and your expectations end up being met.

One implication of Rosenthal and Fode’s study was that experiments need to be double blind. If research assistants are not blinded—if they know which subject is treated and which is not—then their expectations may affect how they treat the subjects, and so may bias the results of the experiment.

But Rosenthal thought the implications of experimenter-expectancy effects were much more profound than just that. He thought—and eventually proved—that the effect applies not only to lab rats but also to people. If you tell teachers that some of their students are especially bright, the teachers treat those students differently, and the children end up learning more as a result.

Expecting greatness can itself lead to greatness. But, conversely, expecting problems leads to problems. Rosenthal’s research made him passionately opposed to IQ tests, because they label some as more promising than others, and those labels have an effect on their own. He argued that managers, school principals, and coaches should all examine their expectations—that just a shift in what they expect can make a difference.

This is all the story of the self-fulfilling prophecy, of the bad kid who stays bad once he realizes that he’s known for being bad. It’s the story of of what happens when we label and categorize teenagers: sluts, jocks, and nerds. It’s the story of how the hierarchies we thought in high school were concrete and rigid were only real because we took them so seriously.

Reading about Rosenthal’s work makes me think of my two young daughters, already awash in the dolls, dresses, and kid nail polish they receive each birthday and holiday. No one ever gives them toy train sets or tools. I ask myself what I expect from them, because, as Rosenthal taught us, expectations matter.