Hand preference in patients with allergy, juvenile cancer, and schizophrenia.

Patients with allergy (n = 50), juvenile cancer (n = 50), and schizophrenia (n = 37), and nonpatient controls (n = 200) were asked to indicate their hand preferences on a 7-point scale (1 = left always, 7 = right always) for the 32-item Waterloo Handedness Questionnaire. Except for patients with schizophrenia, who exhibited a higher incidence of mixed hand preference, groups showed a clear rightward bias. Further analyses suggested that mixed hand preference in schizophrenia was evident more often for unskilled than skilled hand activities.