Manual-skill measures of handedness proposed by Beck (J. Psychol., 1936, 2, 259-272) were compared with a battery of preference tests to determine whether or not the same principal function (laterality, or dominance) was tested by each type of test. The preference measures, which included throwing, near and far reaching for objects, and brushing imaginary lint from clothing, intercorrelated at a level interpreted as showing some common determiners, assumed to be laterality of function. The motor-skill measures did not correlate closely enough with each other or with the preference tests to indicate significant communality. However, when each of the two batteries was pooled the correlation between them was .45, indicating that in a general way the tests were sampling similar behavior; but this level of correlation certainly does not permit substitution of either battery of tests for the other. (PsycINFO Database Record (c) 2006 APA, all rights reserved)