Previous research reported an association of handedness with a variety of neurologic, psychiatric, and immunologic diseases. Most of these studies assessed handedness via questionnaire. This association might therefore result from response bias.Methods
Participants (n=422) completed 2 standard questionnaires to assess handedness and hypochondriasis: the Edinburgh Handedness Inventory and the Whiteley Index. Subjects with past or present neurologic, psychiatric, or immunologic disease or any severe disease were excluded. Separate analyses were made for the overall sample and 2 subsamples with and without a reported medical history of nonsevere diseases.Results
The distribution of handedness is different for subjects with lower versus higher hypochondriac traits: higher scores of hypochondriac traits are associated with weaker right or left-handedness. The subsample reporting a history of nonsevere diseases had even stronger hypochondriac traits and less extreme handedness scores compared with the other subsample.Conclusions
Handedness scores derived from questionnaires are affected by information bias. Future medical and psychologic research on handedness should control for this bias or use empirical methods to assess hand preference.