Lexical decision, pronunciation, and category verification response times (RTs) to natural object and trait hierarchies were measured. Prime and target words consisted of both superordinate and subordinate object and trait category members. Trait words were categorized as desirable and undesirable (Hampson, et al., 1986). Subjects' RTs to object and undesirable trait words displayed similar patterns. In all experiments, RTs to natural-object subordinate target words were significantly more rapid compared to superordinate words. This same pattern was also true for the undesirable traits, but reached significance in only the lexical decision task. The facilitation effect of the prime reached significance for the natural-objects in the category verification experiment and for the undesirable traits in the lexical decision experiment. This pattern of facilitation by the prime were consistent for natural-objects and undesirable traits across all experiments. In each experiment the opposite pattern of results were found for desirable traits. In the pronunciation and lexical decision experiments RTs to desirable superordinate trait words were significantly more rapid compared to desirable subordinate trait words. In all experiments the facilitation by desirable superordinate trait word primes was significantly greater compared to undesirable superordinate trait words. Post-experiment questionnaires indicated that subjects' judgment of the logical hierarchy entailment asymmetries were highly consistent with the norms. Regression analysis of subjects' judgments of the logical entailment between category stimulus pairs indicated no significant systematic relationship. Implications for research on attribution, category memory, and clinical research on cognitive assessment are discussed.