A stimulus from one category increased the rated similarity of two stimuli from another category. In addition, “different” responses, but not “same” responses, to same-category stimuli became slower when they occurred in blocks of trials with a stimulus from a second category. Another experiment employed figural stimuli in which two small disks and a large or very large (extreme) disk were simultaneously present. The extreme disk led to slower “different” and faster “same” responses to the two small disks. Slow “different” and fast “same” responses may indicate high perceived similarity. Consequently, both the second-category stimulus and the extreme disk, although logically irrelevant, may have increased the perceived similarity of more related stimuli. It is concluded that the second-category stimuli and the extreme disk functioned as conventional anchors. The results also call into question memorial and criterial variance theories and support category-superordinate and distance-density theories of the anchor-range effect.