Subjects were exposed to a word-picture association training phase in which each of 2 arbitrary nonsense syllables printed in blue and red font, respectively, were paired with either sexual or aversive photographic images. Subjects were then exposed to an equivalence training procedure that led to the formation of 2 3-member equivalence relations, each containing 1 of the 2 nonsense syllables in their respective color fonts, and 2 novel nonsense syllables in black font. In effect, equivalence class 1 (blue) was associated with sexual images, while equivalence class 2 (red) was associated with aversive images. Subjects were then exposed to a 2-block test in which sexual and aversive images and all members of the trained equivalence relations, presented in black font, were employed. In 1 block, subjects were instructed to produce responses that were compatible with their laboratory history. Specifically, subjects were instructed to produce the same operant response on a computer keyboard upon the presentation of both sexual images and members of equivalence class 1 (blue), and to produce another common response upon the presentation of aversive images and members of equivalence class 2 (red). In the second block of the test the instructions were juxtaposed such that subjects were required to produce common responses to members of classes that were not previously associated with one another (e.g., sexual images and members of equivalence class 2, red). Differences in the fluency of performances across both blocks of the final test were sensitive to subjects' relational and conditioning histories. That is, subjects produced significantly more correct responses during block 1 of the test compared to block 2. Such findings lay the foundation for the development of functionally understood behavioral tests and provide a functional-analytic model of the widely used implicit Association Test. (Contains 2 figures and 1 table.)