Abstract
The theory proposes a nonconscious mechanism that uses stored information (motor memory) to channel existing nervous impulses from brain waves and general afferent stimuli into the appropriate neuromotor coordination centers, subcenters, and efferent nerves, thus causing the desired movement. A consequent hypothesis requires that the simple reaction time will become longer when the response movement is required to be of greater complexity. Data obtained on college men and women, and 12- and 8-year-old boys, are in agreement with the hypothesis. Replacing a very simple finger movement with an arm movement of moderate complexity slows the reaction by about 20 percent; additional complexity produces a further slowing of 7 percent. The speed of the arm movement is considerably faster in college men than in younger boys or in college women. The correlation between reaction time and speed of movement averages approximately zero. Individual differences in ability to make a fast arm movement are about 70 percent specific to the particular movement being made; “general ability for arm speed” occurs only to the extent of 30 percent.