Relational Frame Theory versus Verbal Behavior - Is a synthesis possible?

Skinners (1957) definition of verbal behavior is different from the terms used in relational frame theory. Is there a rationale to combine these two approaches? Each of Skinners verbal operants is described and exemplified with a relational frame analysis. In each case it is possible to identify two types of operants, one based on direct contingencies of reinforcement and the other on arbitrarily applicable relational responding. A synthesis of Skinners verbal operants and relational frame theory is possible and necessary for a behavioral understanding of human language.