The purpose of this paper is to introduce how contemporary behavioral psychology approaches intelligence and higher-order cognitive tasks, as instances of so-called arbitrarily applicable relational responding (AARR). We introduce the contemporary theory Relational Frame Theory (RFT), that suggests that key properties of AARR are mutual entailment, combinatorial entailment, and transformation of stimulus function. Furthermore, AARR are contextually controlled and developed through multiple-exemplar training. We explain these concepts and provide examples of how RFT uses this framework to explain complex cognitive tasks such as language, analogies, a sense of Self, and implicit cognition. Applications of RFT are surveyed. Finally, the relevance of RFT for the AGI audience is discussed.