Hand preference and components of I.Q

An account is given of the hand preferences (measured by questionnaire) of 687 individuals living in a Cambridge suburb. The proportions of right, mixed and left handers differed according to the classification used. Verbal and Performance I.Q. component scores were examined in relation to hand preference. For all classifications, left handers' overall Verbal I.Q. was significantly higher than their Performance I.Q. score, whereas right and mixed handers' Performance I.Q. scores were greater than their Verbal I.Q.s. Left handers scored higher than right and mixed handers on Verbal I.Q. but lower on Performance I.Q. The relationships between patterns of handedness, I.Q. component scores and cerebral dominance are discussed.