Reading/writing vs handedness influences on line length estimation.

Left- and right-handed school children with differing reading/writing experiences (unidirectional left-to-right vs bidirectional) were asked to draw 3-cm lines from right-to-left or from left-to-right with each hand. With either hand, lines drawn from left to right were more accurate than those drawn from right to left, particularly for right-handed left-to-right users; bidirectional readers showed no directional bias. Moreover, bidirectional readers were more accurate than unidirectional readers. The findings support a greater influence of directional scanning effects than handedness on the task of line length estimation.