Which Handedness: Preference or Performance?

Two ways of measuring handedness, questionnaires and hand-efficiency tests, are compared. A method for combining performance scores of 128 children from different hand-efficiency tests to obtain a single handedness score based on efficiency is presented. Handedness classifications according to different thresholds of preference as well as of performance are shown. To select pure right- or left-handers, it is argued that handedness should be established simultaneously through preference questionnaires and performance tests and that only subjects falling simultaneously into the same category on both measures be kept. Advantages and disadvantages of each classification are discussed as well as the relations between efficiency and motor control of upper limb and hand.