Both ACT & its underlying pure behavioral science (RFT) are based on "contextual" underlying assumptions.  It is a world view in which any event is interpreted as an ongoing act inseparable from its current and historical context and in which a radically functional approach to truth and meaning is adopted. These two aspects represent contextualism’s root metaphor and truth criterion, respectively. Contextualism has its roots in philosophical pragmatism, and is also closely related to the view known as selectionism.


There is a strong empirical and conceptual relationship between language and derived stimulus relations. An empirical relationship does not indicate that derived stimulus relations depend upon language or that such relations are mediated by language. When two dependent variables are correlated, one conservative strategy is to determine whether both variables are reflective of the same basic underlying psychological process. If the two areas do overlap at the level of behavioral process, then questions about human language may also be questions about derived stimulus relations, and vice versa.

This is the basic theoretical and empirical research strategy of RFT. The overarching aim of this behavioral research has been to integrate a range of apparently diverse psychological phenomena including, for example, stimulus equivalence, naming, understanding, analogy, metaphor, and rule-following.

Relational Frame Theory adopts the view that the core defining element in all of these, and many other inherently verbal activities, is arbitrarily applicable relational responding, and moreover that such responding is amenable to a learning or operant analysis.

RFT treats relational responding as a generalized operant, and thus appeals to a history of multiple-exemplar training. Specific types of relational responding, termed relational frames, are defined in terms of the three properties of mutual and combinatorial entailment, and the transformation of functions. Relational frames are arbitrarily applicable, but are typically not necessarily arbitrarily applied in the natural language context.

Mutual entailment refers to the derived bidirectionality of some stimulus relations, and as such it is a generic term for the concept of "symmetry" in stimulus equivalence. "Mutual entailment" applies if stimulus A is related to another stimulus B in a specific context, and as a result a relation between B and A is entailed in that context. Combinatorial entailment refers to instances in which two or more relations that have acquired the property of mutual entailment mutually combine. Combinatorial entailment is the generic term for what is called "transitivity" and "equivalence" in stimulus equivalence. Combinatorial entailment applies when, in a given context, A is related to B and B is related to C, and then in that context a relation is entailed between A and C and another between C and A. For example, if A is bigger than B, and B is bigger than C, then a bigger-than relation is entailed between A and C, and a smaller-than relation is entailed between C and A. A transformation of stimulus functions applies when functions of one event in a relational network is altered based on the functions of another event in the network and the derived relation between them. Mutual and combinatorial entailment are regulated by contextual cues (C rel). The transformation of stimulus functions are regulated by additional contextual cues (C func).

The development of relational responding can be organized into a rough list that gradually becomes more and more complex. We are not presenting this list as a set of stages or steps, and we would expect them to be sequenced only in broad terms and even then only if the training history is typical. Nevertheless, this list gives a sense of the complexity that emerges from the small set of core concepts in Relational Frame Theory.

  • Simple examples of verbal understanding
  • Contextually controlled mutual entailment in additional types of stimulus relations
  • Contextually controlled combinatorial entailment in additional types of stimulus relations
  • Contextually controlled transformation of stimulus functions in additional types of stimulus relations
  • Integration of these into additional relational frames
  • Simple examples of genuinely verbal governance of behavior by others
  • Conditional contextual control over the participation of given elements in relational frames
  • More complex examples of verbal understanding
  • Verbal governance of the behavior of others (e.g., verbal mands and tacts)
  • Transformation of stimulus functions across relational networks
  • Increasing acquisition of specific participants in specific relational frames (e.g., vocabulary)
  • Complex interactions between relations (training in one influences development of another)
  • Elaborated and increasingly subtle contextual control over relational responding (e.g., syntax; number of relational terms)
  • Nonarbitrary properties serve as a relational context for arbitrarily applicable relational responses
  • With acquisition of equivalence, time or causality, and evaluation, the development of relational sentences that function fully as rules
  • Relating relational networks
  • Transformation of stimulus functions based on the relating of relational networks
  • Relating relational networks under the control of nonarbitrary properties of the environment
  • Regulation of the behavior of the listener through the establishment of relational networks in the listener
  • With the acquisition of hierarchical class membership, use of relational networks to abstract nonarbitrary properties and to have these properties participate in relational frames
  • Abstracting properties of the nonarbitrary environment based on relational networks and the relating of relational networks
  • With the acquisition of temporal, contingency, and causal relational frames, increased insensitivity to temporal delays
  • Development of perspective-taking and sense of self
  • Construction of the verbal other
  • Construction of the conceptualized group
  • Contextual control of relational responding by the nonarbitrary and arbitrary properties of the listener
  • Regulation of the behavior of the listener by orienting the listener to abstracted features of the environment
  • Acquisition of increasingly abstract verbal consequences
  • Self-rule generation and self rule-following
  • Increasing dominance of the verbal functions of the environment

The foregoing provides a summary of the key features of RFT. The key concept that underlies Relational Frame Theory is extremely simple—try to think of relating per se as learned behavior. As the list above shows, however, applying this simple idea leads to many specific points—the nature of an arbitrarily applicable relational response, the role of context, the varieties of relational responses, the role of the nonarbitrary environment, networks of relations, the use of these abilities to solve problems, the development of self, and so on.

Stephen Hayes