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The current research investigates sources of variability in subjects ’ asymmetry scores on commonly used laterality tasks. In particular, subjects ’ asymmetry scores on four bilateral tachistoscopic tasks and one free-vision task were entered into a principal component analysis (PCA) in order to investigate components that explain the maximum variance of the sample. The results indicate that about half of the variation (45.2%) in asymmetry scores on both tachistoscopic and free-vision tasks is attributable to individual differences in characteristic per-ceptual asymmetry. The amount of variance explained by this characteristic perceptual asymmetry component is similar in a sample of dextrals and a sample of sinistrals. No significant relation was revealed between individual differences in characteristic perceptual asymmetry and performance on various verbal and spatial cognitive tasks. 0 1990 Academic Press, Inc. Perceptual asymmetries of normal dextrals as indexed by laterality tasks (e.g., dichotic listening, lateralized tachistoscopic presentation) are We are grateful to the Spencer Foundation for supporting this research. We thank Jerre Levy, Howard Nusbaum, and Steven Shevell for helpful comments and suggestions on an earlier version of this article. Address all correspondence and requests for reprints t