Effects of prior conditional discrimination training, symmetry, transitivity, and equivalence testing on the emergence of new equivalence classes

Prior studies have shown that the establishment of equivalence classes using the simple-to-complex protocol significantly enhanced the emergence of other new equivalence classes under the simultaneous protocol (yield). The current experiment showed how those enhancement effects were influenced by each component of the protocol used to establish the initial equivalence classes. Yield during the simultaneous protocol was not improved following the prior establishment of other baseline conditional discriminations alone. The prior establishment of the conditional discriminations plus symmetry testing produced a small increment in yield. The prior establishment of conditional discriminations plus transitivity testing produced a very large increment in yield. The prior establishment of conditional discriminations plus transitivity and symmetry testing, or symmetry, transitivity and equivalence testing (i.e., equivalence class formation) did not produce further increments in yield. Thus, the enhanced emergence of new equivalence classes under the simultaneous protocol was due to prior demonstrations of transitivity rather than to the prior establishment of other equivalence classes. Some possible behavioral processes responsible for these effects are discussed.