Danger and Usefulness affect word recognition (e.g., Wurm & Vakoch, 2000), and a related construct affects memory (e.g., Nairne, Thompson, & Pandeirada, 2007). We tested hypotheses about differential effects of these dimensions, based on the relevance of concepts relative to the time perceptual systems underwent selection pressures. In two experiments participants made auditory and visual lexical decisions for nouns rated on Danger, Usefulness, and "Ancientness. " Danger interacted with Ancientness in both auditory and visual processing. Increasing Danger led to faster RTs and better accuracy only for words judged to have ancient relevance. Interactions with participant gender were seen in both auditory and visual analyses. Consistent with Wurm, Whitman, Seaman, Hill, and Ulstad (2007), men's but not women's auditory performance improved with increasing Danger. The beneficial effect of Usefulness on accuracy was greater for women than for men in both experiments. Danger and Usefulness effects seem to reflect a general principle underlying human cognition.Individuals are bombarded with environmental stimuli, and how one perceives these stimuli allows for their categorization. This leads to the maintenance of an organized and coherent view of the world. While many of the types of stimuli have changed, this task is the same as that our early ancestors faced, although the consequences then were frequently much more severe for any errors in categorization. It seems reasonable to surmise that those who survived to live another day were able to do so in part because of their ability to quickly and correctly categorize stimuli that were relevant to their continued existence. In fact, many of our species'