FIGURE 4.

Distribution of directional asymmetry values. These histograms illustrate the distribution of directional asymmetry values ${\left(\overline{L-R}\right)}_i$ for the 182 bilateral linear distances in the sagittal and control groups. A dotted line indicates the axis of symmetry at a directional asymmetry score of zero. In both samples, the mean directional asymmetry was less than zero, and negative values were more extreme, indicating a right-side bias (i.e., bilateral linear distances tend to be greater on the right side).