Contrary to popular opinion, the qwerty design was not actually invented to slow typists down. Rather, the layout was intended to place common two-letter combinations on opposite sides of the keyboard. On manual typewriters, each key is mechanically connected to a lever that has the reversed image of a letter on it. If a typist were to hit two keys on the same side of the keyboard in rapid succession, the second lever on its way up would hit the first on its way down, the keys would become stuck together, and the typist would have to stop typing and unstick the keys. The qwerty layout was a clever design that minimized this problem.
Most people learn to type on a qwerty keyboard.
Most people are reluctant to switch because they're afraid of how long it will take them to learn the new arrangement. Since typists were scarce during the war, the U.S. Navy selected fourteen typists for a 1944 study to assess whether Dvorak retraining would be feasible. Dvorak found that it took an average of only 52 hours of training for those typists' speeds on the Dvorak keyboard to reach their average speeds on the qwerty keyboard. By the end of the study their Dvorak speeds were 74 percent faster than their qwerty speeds, and their accuracies had increased by 68 percent. Dvorak believed that hurdling and awkward keystroke combinations were responsible for most of the common errors typists make.