Friman, P. C., Wilson, K. G., & Hayes, S. C. (1998). Behavior analysis of private events is possible, progressive, and nondualistic: A response to Lamal. Journal of Applied Behavior Analysis, 31, 707-708.

Peter Lamal's response to our paper on anxiety (Friman, Hayes, & Wilson, 1998) is as much a critique of Skinner's approach to private events (e.g., Skinner, 1984) as it is a critique of our paper. Skinner's position constituted a rebuttal to the ubiquitous dualistic notion that behavior is but a mere manifestation of unseen cognitive and emotional processes that have vitalistic primacy. Skinner attempted to eliminate this dualism by defining all human activity as behavior, even when the activity is observable to the actor alone. In contrast, Lamal claims that private events have merely putative or hypothetical status as behavior and that only public events can be studied scientifically. But by excluding private events from definitions of behavior because they are so inherently different from public events, Lamal has merely adopted a different form of dualism. We side with Skinner's more thoroughgoing nondualistic stance.

Lamal relies heavily on Zuriff, who claimed that "no evidence is currently available to show that verbal responses enter into causal relationships with private events or that these private events are stimuli in the sense of conforming to the same laws as their overt counterparts" (1988, p. 572). The evidence that private events can be tacted and can be successfully subjected to scientific analysis is accumulating, however. For example, private events can acquire discriminative properties (e.g., Oliveto, Bickel, Hughes, Higgins, & Fenwick, 1992), can enter into equivalence relations with public events (DeGrandpre, Bickel, & Higgins, 1992), and can participate in the regulation of larger behavioral episodes (Taylor & O'Reilly, 1997). Behavioral methods even exist that allow researchers to know whether statements about private events are functionally veridical, at least under some circumstances (Hayes, White, & Bissett, 1998).

Lamal claims that "a focus on such hypothetical constructs as thoughts entails threats to the empirical nature and objectivity of behavior analysis" (p. 706). This view has three problematic components. First, it designates thoughts as hypothetical constructs despite the obvious (to Lamal) role thoughts played in formulation of the view. Second, that study of private events threatens empiricism seems to be refuted by data such as those provided in the previous paragraph. Third, the alleged threat that private events pose for the objectivity of behavior analysis results from mistaking interobserver agreement for objectivity.

From a somewhat different perspective, Zuriff's 1985 remarks on thinking are actually supportive of our anxiety paper. Specifically, Zuriff stated that thinking is a vague term from common language, not a technical term, and therefore behaviorist theories "are under no obligation to define, interpret, or explain it. However, behaviorist theories are obliged to explain the behavioral phenomena to which the term `thinking' refers" (p. 171). Substituting the term anxiety for the term thinking in these remarks provides a statement that echoes a major point in our paper. As we made clear, the term anxiety is not a technical term; it is imprecise, metaphorical, and idiomatic. But there is a large class of important phenomena occasioning the term that requires explanation. Our paper offered one, albeit incomplete, using relational frame theory in general and avoidance responding in particular.

A final major point of contention between us and Lamal involves the value of first-person reports. We proposed that they are a potential source of clinical and scientifically valuable information, whereas Lamal assigns them little value. Our position, however, is in the pragmatic behavior-analytic mainstream because it is clear that "something can be learned about a person's history by asking how he feels" (Skinner, 1984, p. 579), as is shown empirically in the basic and applied literatures on self-report methods (see Critchfield, Tucker, & Vuchinich, in press, for an exceptional review). The literature demonstrating the bidirectionality of language also suggests that speaking affects the speaker (Hayes & Wilson, 1993), and thus that first-person reports are important in the understanding of complex human behavior.

The slippery slope to which Lamal points is, perhaps, like a hill that is slippery on both sides. Down the one side lies mentalism, which is as much a concern to us as it is to Lamal. Our paper provided a critique of, and a behavior-analytic alternative to, mentalistic accounts of anxiety. Down the other side, however, is methodological behaviorism, logical positivism, and mechanistic reductionism. Skinner (1984) and others (e.g., Ryle, 1949; Wittgenstein, 1953) have warned of troubles with this side of the hill, and we worry that Lamal's position may take us in that direction. The surest method for staying on top of the hill is to conduct comprehensive behavior analyses of complex human behavior, both public and private.

REFERENCES

Critchfield, T. S., Tucker, J. A., & Vuchinich, R. E. (in press). Self-report methods. In K. A. Lattal & M. Perone (Eds.), Handbook of methods in operant behavior. New York: Plenum.

DeGrandpre, R. J., Bickel, W. K., & Higgins, S. T. (1992). Emergent equivalence relations between interoceptive (drug) and exteroceptive (visual) stimuli. Journal of the Experimental Analysis of Behavior, 58, 9—18.

Friman, P. C., Hayes, S. C., & Wilson, K. (1998). Why behavior analysts should study emotion: The example of anxiety. Journal of Applied Behavior Analysis, 31, 137—156.

Hayes, S. C., White, D., & Bissett, R. T. (1998). Protocol analysis and the "silent dog" method of analyzing the impact of self-generated rules. The Analysis of Verbal Behavior, 15, 57—63.

Hayes, S. C., & Wilson, K. G. (1993). Some applied implications of a contemporary behavior-analytic account of verbal events. The Behavior Analyst, 16, 283—301.

Oliveto, A. H., Bickel, W. K., Hughes, J. R., Higgins, S. T., & Fenwick, J. W. (1992). Triazolam as a discriminative stimulus in humans. Drug and Alcohol Dependence, 30, 133—142.

Ryle, G. (1949). The concept of mind. New York: Barnes & Noble. Skinner, B. F. (1984). The operational analysis of psychological terms (and commentaries). Behavioral and Brain Sciences, 7, 547—582.

Taylor, I., & O'Reilly, M. F. (1997). Toward a functional analysis of private verbal self-regulation. Journal of Applied Behavior Analysis, 30, 43—58.

Wittgenstein, L. (1953). Philosophical investigations. New York: Macmillan. Zuriff, G. E. (1985). Behaviorism: A conceptual reconstruction. New York: Columbia University Press.

Zuriff, G. E. (1988). Radical behaviorism and theoretical entities. Behavioral and Brain Sciences, 7, 572.