Symmetry suppression was conducted for five subjects who demonstrated a tendency to derive equivalence relations based on conditional discrimination training in a match-to-sample procedure. Symmetry suppression was applied in three consecutive sessions in which symmetrical responses were suppressed for one stimulus class in the first condition, two stimulus classes in the second condition, and all three stimulus classes in the final condition. Symmetry suppression slowed the emergence of transitivity for two subjects and prevented it for the other three. Results indicated that unplanned features of stimulus configurations emerged as discriminative variables that controlled selection responses and altered the function of consequent stimuli. Disruption of cognitive development by conflicting contingencies in natural learning environments is discussed.