One of the most revealing studies of human nonverbal communication was performed using an animal with which humans rarely share their homes, at least not intentionally: the rat. In that study, students in an experimental psychology class were each given five of those creatures, a T-shaped maze, and a seemingly simple assignment.6 One arm of the T was colored white, the other gray. Each rat’s job was to learn to run to the gray side, at which time it would be rewarded with food. The students’ job was to give each rat ten chances each day to learn that the gray side of the maze was the one that led to food and to objectively record each rat’s learning progress, if any. But it was actually the students, not the rats, who were the guinea pigs in this experiment. The students were informed that through careful breeding it was possible to create strains of maze-genius and maze-dummy rats. Half the students were told that their rats were the Vasco da Gamas of maze explorers, while the other half were told that theirs had been bred to have no sense of direction at all. In reality, no such selective breeding had been performed, and the animals were effectively interchangeable, except perhaps to their mothers. The real point of the experiment was to compare the results obtained by the two distinct groups of humans, to see if their expectations would bias the results achieved by their rats.
The researchers found that the rats the students thought were brilliant performed significantly better than the rats believed to be on the dumb side. The researchers then asked each student to describe his or her behavior toward the rats, and an analysis showed differences in the manner in which students in each group related to the animals. For example, judging from their reports, those who believed their rats to be high achievers handled them more and were gentler, thereby communicating their attitude. Of course, that might have been intentional, and the cues we are interested in are those that are unintentional and difficult to control. Luckily, another pair of researchers shared that curiosity.7 They essentially repeated the experiment but added an admonishment to the students that a key part of their task was to treat each rat as they would if they had no prior knowledge about its breeding. Differences in handling, they were warned, could skew the results and, by implication, their grade. Despite these caveats, the researchers also found superior performance among the rats whose handlers expected it. The students attempted to act impartially, but they couldn’t. They unconsciously delivered cues, based on their expectations, and the rats responded.
It’s easy to draw analogies with how unconsciously communicated expectations might also affect human performance, but are they accurate? One of the researchers in the rat study, Robert Rosenthal, decided to find out.8 His plan was to again have his students conduct an experiment, but this time they would experiment on people, not rats. That, of course, involved altering the experiment to be better suited to human subjects. Rosenthal came up with this: he asked the student experimenters—who were themselves the true subjects of the experiment—to show their subjects photographs of people’s faces and request that they rate each face on the degree of success or failure they felt it reflected. Rosenthal had pretested a large set of photos, and he gave his students only those photos that had been judged as neutral. But that’s not what he told them. He said he was trying to duplicate an experiment that had already been performed, and he told half the experimenters that their stack of photos depicted faces that had been rated as successful, and the other half that theirs were rated as failures.
In order to make sure the student experimenters did not use any verbal language to communicate their expectations, Rosenthal gave them all a written script to follow and warned them not to deviate from it in any way or speak any other words. Their job was merely to present the photos to their subjects, read the instructions, and record their subjects’ responses. One could hardly take stronger precautions to discourage experimenter bias. But would their nonverbal communication nevertheless flag their expectations? Would the human subjects respond to these cues just as the rats had done?
Not only, on average, did the students who expected their subjects to accord high success ratings to the photos obtain such ratings but, in addition, every single student who had been led to expect high ratings obtained higher ratings from their subjects than did any of those expecting low ratings. Somehow they were subliminally communicating their expectations. But how?
A year later, another set of researchers repeated Rosenthal’s study, with a twist.9 During the course of that study, they recorded the experimenters’ instructions to their subjects. Then they conducted another experiment, in which they eliminated the human experimenters and instead communicated the instructions to the subjects using the tape recordings, thus getting rid of all cues other than those that could be transmitted through the sound of the voice. Again the results were biased, but only about half as much. So one important way the experimenters’ expectations were communicated was through the inflection and tonal quality of their voices. But if that is just half the story, what’s the other half? No one knows for sure. Over the years, many scientists have tried to find out by doing variants of the experiment, but though they confirmed the effect, none was ever able to specify any more precisely just what the other nonverbal signals were. Whatever they were, they were subtle and unconscious and probably varied considerably among the individuals.
The lesson learned has obvious applications in our personal and professional lives, with regard to our family, our friends, our employees, our employers and even the subjects being interviewed in a marketing focus group: whether or not we wish to, we communicate our expectations to others, and they often respond by fulfilling those expectations. You can probably think of expectations, whether stated or not, that you have regarding most people you interact with. And they have expectations of you. That’s one of the gifts I received from my parents: to be treated like the Vasco da Gama rats, to be made to feel as if I could navigate my way to success in whatever I set out to do. It’s not that my parents talked to me about their belief in me, but I somehow felt it, and it has always been a source of strength.