Thomas S. Critchfield

Human sensitivity to reinforcement in operant choice: How much do consequences matter?

The results of many human operant conditioning experiments appear to show that humans are less sensitive than nonhumans to operant consequences, suggesting species discontinuities in basic behavioral processes. A reanalysis of 31l data sets from 25 studies employing variable-interval schedules of reinforcement designed to assess sensitivity to reinforcement corroborates the claim that human behavioral allocation among alternatives often deviates from predictions based on rates of experimentally programmed consequences. Close inspection of the studies in question, however, suggests that methodological issues contribute heavily to the differences noted so far between humans and nonhumans and that an explanation based upon species discontinuities is not tenable.

Teaching Brain-Behavior Relations Economically with Stimulus Equivalence Technology.

Instructional interventions based on stimulus equivalence provide learners with the opportunity to acquire skills that are not directly taught, thereby improving the efficiency of instructional efforts. The present report describes a study in which equivalence-based instruction was used to teach college students facts regarding brain anatomy and function. The instruction involved creating two classes of stimuli that students understood as being related. Because the two classes shared a common member, they spontaneously merged, thereby increasing the yield of emergent relations. Overall, students mastered more than twice as many facts as were explicitly taught, thus demonstrating the potential of equivalence-based instruction to reduce the amount of student investment that is required to master advanced academic topics.

Self-Report Methods

Human communication is unique among behavioral phenomena. No other type of behavior so readily serves both as a focus of study and as a measurement tool in the study of other behavior. Put simply, when we study human behavior, we have the luxury of asking our subjects what they know about it, and in many areas of psychology, this has been regarded as an offer too good to refuse. Unlike most areas of psychology, however, the experimental analysis of behavior matured primarily in the animal laboratory (Iversen & Lattal, 1991a,b; Skinner, 1996). This historical context may help to explain the trepidation with which operant researchers have faced the fact that humans regularly talk, write, and otherwise exchange information. Verbal capabilities have not been a central focus in the extension of the experimental analysis of behavior to human behavior (e.g., Oah & Dickinson, 1989), and consistent with this pattern, researchers have shown relatively little interest in data generated through verbal self-reports. In a recent 5-year survey of the Journal of the Experimental Analysis of Behavior, for example, self-report data provided a dependent measure in only about one-third of the studies conducted with human subjects.1 In about 70% of these cases, self-reports served as a collateral measure rather than the primary dependent variable.

Translational contributions of the experimental analysis of behavior.

It has been argued that to increase societal impact behavioral researchers must do more to address problems of obvious practical importance. The basic science wing of behavior analysis has been described as especially detached from this goal, but is it really necessary that basic science demonstrate social relevance? If so, why hasn’t this occurred more often, and what can be done to improve the status quo? To address these questions and to stimulate discussion about the future of basic behavior science, I describe two widely embraced arguments in favor of pure basic science (that which is undertaken without concern for practical applications); explain why a translational research agenda is likely to better recruit tangible support for basic science; propose that addressing practical problems does not require basic science to abandon its focus on fundamental principles; and identify some possible impediments to translational innovation that may need to be addressed for basic behavior science to increase its translational footprint.

Efficiently Establishing Concepts of Inferential Statistics and Hypothesis Decision Making through Contextually Controlled Equivalence Classes

Computerized lessons that reflect stimulus equivalence principles were used to teach college students concepts related to inferential statistics and hypothesis decision making. Lesson 1 taught participants concepts related to inferential statistics, and Lesson 2 taught them to base hypothesis decisions on a scientific hypothesis and the direction of an effect. Lesson 3 taught the conditional influence of inferential statistics over decisions regarding the scientific and null hypotheses. Participants entered the study with low scores on the targeted skills and left the study demonstrating a high level of accuracy on these skills, which involved mastering more relations than were taught formally. This study illustrates the efficiency of equivalence-based instruction in establishing academic skills in sophisticated learners.

Generality of the matching law as a descriptor of shot selection in basketball.

Based on a small sample of highly successful teams, past studies suggested that shot selection (two- vs. three-point field goals) in basketball corresponds to predictions of the generalized matching law. We examined the generality of this finding by evaluating shot selection of college (Study 1) and professional (Study 3) players. The matching law accounted for the majority of variance in shot selection, with undermatching and a bias for taking three-point shots. Shot-selection matching varied systematically for players who (a) were members of successful versus unsuccessful teams, (b) competed at different levels of collegiate play, and (c) served as regulars versus substitutes (Study 2). These findings suggest that the matching law is a robust descriptor of basketball shot selection, although the mechanism that produces matching is unknown.

Temporal discounting predicts individual competitive success in a human analogue of group foraging.

Twenty groups of college undergraduates (N=9-12) participated in a discrete-trials analogue of group foraging in which points, exchangeable for course credit, were the resource to be acquired. Group matching of foragers to patch resource availability was well described by the generalized Ideal Free Distribution, with undermatching (imperfect sensitivity to resource differentials) the norm. Individuals differed on several measures of competitive success, and a measure of temporal discounting (TD) accounted for a significant proportion of the variance in these measures. Tendencies in switch patterns and visit durations differed for the most-impulsive and least-impulsive individuals in a fashion that was consistent with a TD interpretation. When competitive weights, defined in terms of TD scores, were substituted for counts of individuals in the generalized Ideal Free Distribution, group-matching slopes more closely approximated perfect sensitivity than in standard analyses. This was true for groups incorporating all impulsive individuals, all non-impulsive individuals, or a broad range of TD scores. The results suggest that well-understood individual psychological processes are associated with competitive ability in group choice.

Self-Recording, Instructions, and Public Self-Graphing Effects on Swimming in the Absence of Coach Verbal Interaction

This experiment systematically replicated a study by McKenzie and Rushall, who reported that a self-recording intervention enhanced swimming workout performance. In that study, anecdotal evidence suggested that reactive effects resulted at least partially from concomitant increases in coach prompting and praise. In the present study, young competitive swimmers self-recorded during 10-min sessions. Their coach observed but interacted with the swimmers only in a limited, scripted fashion. After a baseline condition in which negligible swimming occurred, instructions to perform, self-recording, and public self-graphing of self-recorded data were introduced in different conditions using a modified multiple-baseline (across-subjects) design. Instructions produced transient increases in swimming rates, whereas self-recording increased and maintained swimming above terminal rates in the instructions-only condition. The self-graphing condition produced no further rate increases but disrupted recording accuracy. The results suggest that direct reactive effects could have been present in McKenzie and Rushalls study and add to a body of literature indicating that reactivity can be independent of immediate social influences.

Using stimulus equivalence technology to teach statistical inference in a group setting.

Computerized lessons employing stimulus equivalence technology, used previously under laboratory conditions to teach inferential statistics concepts to college students, were employed in a group setting for the first time. Students showed the same directly taught and emergent learning gains as in laboratory studies. A brief paper-and-pencil examination, suitable for classroom use, captured effects demonstrated previously through laboratory tests. The results support the extension of the lessons to more naturalistic settings.

Transportability of Equivalence-Based Programmed Instruction: Efficacy and Efficiency in a College Classroom.

College students in a psychology research-methods course learned concepts related to inferential statistics and hypothesis decision making. One group received equivalence-based instruction on conditional discriminations that were expected to promote the emergence of many untaught, academically useful abilities (i.e., stimulus equivalence group). A negative control group received no instruction, and a positive (complete instruction) control group received instruction on all possible relations (those taught to, and emerging untaught in, the stimulus equivalence group). On posttests, the stimulus equivalence group performed as well as the positive control group (and both outperformed the negative control group), but those in the equivalence-based instruction condition achieved this outcome with significantly less training, thereby demonstrating the efficiency of equivalence-based instruction. Social validity measures indicated that participants found the instruction to be beneficial and as enjoyable as traditional teaching methods.