Ambilaterality: definition from handedness preference questionnaires and potential significance.

Defining handedness according to the results of preference questionnaires is operational. Most often, handedness is defined according to the extremes of the handedness range or equal divisions of the entire handedness range. These definitions may exclude ambilateral (ambidextrous) subjects from analysis or may fail to separate out subjects with intermediate handedness scores. Examples from the literature are presented to show that subjects with handedness scores in the weak right-handedness range may have characteristics that distinguish them from subjects in other segments of the handedness spectrum. Handedness studies should assess the middle handedness range using a scoring method which identifies subjects in this range.