Believe you can do a thing, or believe you cannot. In either case you're right.
By 1954, many people had come close to running a mile in under four minutes. Times of 4:03, 4:02 and even 4:01 had been posted. But 4:00 seemed to be the limit. People started believing it was physically impossible--no matter how much training or ability--for a human to run a mile in under 4 minutes. Many scientists and doctors agreed.
Then on May 6, 1954, Roger Bannister ran a mile in less than 4 minutes--to the shock of the world. Asked how he'd accomplished the impossible, Bannister answered, "It was never a physical barrier, it was a mental barrier." Bannister believed he could run as fast as he did. Once Bannister proved it could be done, other runners believed it, too. Within one year, 37 runners broke the belief barrier to run a sub 4-minute mile. The year after that, 300 other runners did the same thing.
Before they became management and educational buzz words, Henry Ford captured the concept of "self-fulfilling prophecy" when he said,
"Whether you believe you can do a thing or not, you are right."
Today there's little doubt in business, athletics, education, the military and law enforcement that people's beliefs and expectations can incredibly affect their own performance. But, as a leader or trainer, can your beliefs about the officers, recruits and staff you lead or train, affect their performance? And, if so, how?
The Pygmalion Effect aka The Self-Fulfilling Prophecy
The Pygmalion Effect has been so studied and documented that it is a mainstay in business schools and teacher training programs. The term comes from a Greek myth about a sculptor named Pygmalion. Much later, George Bernard Shaw wrote a play loosely based on the myth, from which the musical and movie My Fair Lady was adapted. There's a web link below where those inclined can read more about the myth, the play, and the musical.
The management and teacher training concept is this. We treat people, consciously or unconsciously, consistent with our beliefs about them. In response, they act in a manner consistent with our beliefs--even if those beliefs are inaccurate. Their responding behavior then confirms our beliefs and becomes a self-fulfilling prophecy--for us and them.
Oft-repeated class experiments establish that when teachers are led to believe that some children are bright, gifted, quick learners, the performance of those children can be improved by as much as twice that over other children in the class. Similarly, when a teacher is told those same children are slow, dull learners, their performance significantly decreases.
Comparable experiments have been documented in the work world. Researcher Albert King conducted an experiment on the power of managers' beliefs. In the experiment, the president of a company separately gave four managers of comparable plants identical changes in work procedures. The president individually told the managers of plants one and two that he expected the new procedures to increase productivity, but have no effect on morale (as measured by grievances, absences and turnover). He advised the managers of plants three and four that he expected the same procedures to have no effect on productivity, but would increase morale.
What do you think happened? Across the nation, law enforcement leaders and trainers respond that morale and productivity went up in all the plants. They reason that in plants three and four, when morale went up, productivity increased as a result, and that in plants one and two, when productivity increased, workers were more satisfied. Instead, the results in all four plants were exactly what the president told the managers he believed they would be.