Note on criteria for writing posture used to test Levy and Reid's cerebral organization hypotheses.

Apparent ambiguities in Levy and Reid's writing posture criteria and dissimilar criteria used by other investigators are discussed. Classification of inverted writing postures by a diagram which, as Levy and Reid indicated in 1976, depicts typical writing positions is questioned because their 1978 paper suggests that these diagrammed positions were only an intermediary stage in the classification of some inverters. Results of studies using dissimilar criteria for writing posture appear to be difficult to compare because subjects who may differ in cerebral organization might be placed in the same category. Some of these studies introduced another possible source of confounding because different tasks were used to test lateralization of function. Since different tasks seem to study distinctive facets of language, lateralization of one function in sinistrals, thought to be less lateralized than dextrals, does not predict lateralization of any other function. These considerations suggest that an adequate test of Levy and Reid's ideas concerning the relationship among handedness, hand posture during writing, sex, and cerebral organization requires the development of a standard set of valid criteria for writing posture.