Handedness as a function of test complexity.

Handedness as a function of test complexity was investigated with two tests, Dotting and Tapping-on-squares. For each one three levels of complexity were established by varying radius (Dotting) and square sides (Tapping-on-squares). Administration of the different complexity levels to a total of 310 third and fourth grade boys and girls showed that the rate of left-handedness increased from 6% to 16% with decreasing level of test complexity. It is concluded that optimal classification of handedness is only made possible by maximal levels of test complexity, which have to be established empirically for different populations.