The Case of the Hypnotized Salesman

In the book, Secrets of Successful Selling, John D. Murphy tells how Elmer Wheeler used Lecky's theory to increase the earnings of a certain salesman:
"Elmer Wheeler had been called in as a sales consul­tant to a certain firm. The sales manager called his atten­tion to a very remarkable case. A certain salesman always managed to make almost exactly $5,000 per year, regard­less of the territory they assigned to him or the commis­sion he was paid.
"Because this salesman had done well in a rather small territory, he had been given a larger and much better one. But the next year his commission amounted to almost the same amount as that he had made in the smaller one— $5,000. The following year the company increased the commission paid to all salesmen, but this salesman still managed to make only $5,000. He was then assigned one of the company's poorest territories—and again made the usual $5,000.
"Wheeler had a talk with this salesman and found that the trouble was not in the territory but in the salesman's own valuation of himself. He thought of himself as a $5,000-per-year man and as long as he held that concept of himself, outside conditions didn't seem to matter much.
"When he was assigned a poor territory, he worked hard to make that $5,000. When he was assigned a good territory, he found all sorts of excuses to coast when the $5,000 was in sight. Once, when the goal had been reached, he got sick and was unable to work any more that year, although doctors could find nothing wrong with him and he miraculously recovered by the first of the next year."