Abstract
The robust vocabularies acquired by neurotypical children are impossible to account for by direct instruction alone, and as such incidental acquisition must play a role. A variety of explanations for the source of this exponential language growth have been put forth by theorists across related disciplines. We provide our general reflections on interactions that exist among the possible sources of incidental language acquisition that have been put forth by both behavior-analytic and cognitive perspectives. We first consider the behavior-analytic perspectives of bidirectional naming (BiN), stimulus equivalence (SE), and relational frame theory (RFT). Next, we consider the cognitive perspective of fast mapping. We also provide comparisons between the behavior-analytic principle of exclusionary performance, and the cognitive principles of mutual exclusivity and the principle of contrast as additional sources for incidental acquisition of novel object–word labels and meanings. We reflect on points of contact and departure between these cross-disciplinary theories of human language and cognition.