The Experimental Analysis of Behavior

The distinction between first- and second-order ability in the philosophy of action enables new clarity in the discussion of behavioral control in addiction. Addiction involves automated patterns of thought and behavior that undermine the (first-order) ability to reliably abstain. However, addicts retain a second-order ability to reliably abstain if they remain able to learn the "epistemic prerequisites" of reliable abstinence, including addiction-specific metacognitive skills and cue-avoidance strategies. The second-order ability to reliably abstain depends to a significant extent on socioeconomic situation and access to the right social resources. This "Epistemic Prerequisite Model" supports the view that addiction is a compulsion, and suggests that moral responsibility in addiction depends on factors relating to both orders of ability.

Comparative psychologists have been criticized for using a limited number of species in drawing general conclusions about broad behavioral processes. There are numerous examples, however, of the inclusion by behavior analysts of atypical subjects in their research. To examine the frequency and diversity in subject species used in the experimental analysis of behavior (EAB), JEAB publications between 1958 and 2023 were reviewed for their use of subjects other than pigeons, rats, humans, and nonhuman primates. Two hundred and twenty-one occurrences of these atypical subjects were found across 204 articles, with 65 distinct species across both vertebrate and invertebrate taxa. The highest spikes in the frequency of atypical subject use occurred in the earliest and latest JEAB issues. The results are discussed in terms of the reasons for using diverse species, trends in use over time, and how EAB might benefit from continued, or even increased, diversification in the species used in its research.

Fixed‐interval schedules of intravenous cocaine presentation were examined as a function of injection dose (0.32 to 0.64 mg/kg) and interval duration (200 to 400 sec) in two rats. Cocaine was found to exert a dose‐related temporal control over the initiation of responding that was unaffected by the fixed‐interval contingency. Fixed‐interval pause duration was linearly related to injection dose and was the same duration as the interresponse time found on continuous reinforcement schedules of cocaine presentation. The fixed‐interval pause remained constant with changes in interval duration. Characteristic fixed‐interval patterns of responding were observed. However, overall response rates were inversely related to injection dose and directly related to interval duration. Running response rates varied unsystematically with both variables. These findings are at variance with results typically found in studies of fixed‐interval food and electric shock presentation.

PHARMACOL BIOCHEM BEHAV 30(3) 753-754, 1988.--Apomorphine has been reported to increase shock-suppressed drinking, which suggests that it might have antianxiety activity. Because some drugs that increase shock-suppressed drinking are not active in other punishment procedures, the effects of apomorphine on punished and unpunished responding maintained by a multiple fixed-interval, fixed-interval schedule of food presentation were studied in rats. At doses from 3.125 to 100/zg/kg, apomorphine failed to increase punished or unpunished responding. In contrast, pentobarbital produced large increases in punished responding maintained by a fixed-interval schedule of food presentation.

Gamma-hydroxybutyrate (GHB) is a drug with significant abuse potential. The present study aimed to assess the relative value of escalating doses of GHB to current GHB users via the Multiple Choice Procedure (MCP), and to validate that the dose rated highest with the MCP would be self-administered at a greater rate than placebo. Participants were 5 current GHB users who were not currently trying to stop using GHB. To examine the value of escalating doses of GHB, the following doses of GHB were used: 0 (placebo), 12.5, 25, 37.5, and 50 mg/kg. Participants typically assigned higher doses of GHB had higher crossover points on the MCP. During choice sessions, participants made repeated choices between administering GHB, placebo or nothing. All participants selected GHB exclusively (5 out of 5 instances) except for one participant who selected GHB on 4 out of 5 instances, thus 96% (i.e., 24/25) of choices were for active GHB. Based on these data, GHB appears likely to function as a dosedependent reinforcer for humans based on our sample.

Incentive theory is extended to account for concurrent chained schedules of reinforcement. The basic model consists of additive contributions from the primary and secondary effects of reinforcers, which serve to direct the behavior activated by reinforcement. The activa- tion is proportional to the rate of reinforcement and interacts multiplicatively with the directive effects. The two free parameters are q, the slope of the delay of reinforcement gradient, whose value is constant across many experiments, and b, a bias parameter. The model is shown to provide an excellent description of all results from studies that have varied the terminal-link schedules, and of many of the results from studies that have varied initial-link schedules. The model is extended to diverse modifications of the terminal links, such as varied amount of reinforcement, varied signaling of the terminal-link sched- ules, and segmentation of the terminal-link schedules. It is demonstrated that incentive theory provides an accurate and integrated account of many of the phenomena of choice.

Most current models of delay discounting multiply the nominal value of a good whose receipt is delayed, by a discount factor that is some function of that delay. This article reviews the logic of a theory that discounts the utility of delayed goods by adding the utility of the good to the disutility of the delay. In limiting cases it approaches other familiar models, such as hyperbolic discounting. In nonlimit cases it makes different predictions, generally requiring, inter alia, a magnitude effect when the value of goods is varied. A different theory is proposed for conditioning experiments. In it utility is computed as the average reinforcing strength of the stimuli that signal the delay. Both theories are extended to experiments in which degree of preference is measured, rather than adjustment to iso-utility values.

The reinforcers that maintain target instrumental responses also reinforce other responses that compete with them for expression. This competition, and its imbalance at points of transition between different schedules of reinforcement, causes behavioral contrast. The imbalance is caused by differences in the rates at which different responses come under the control of component stimuli. A model for this theory of behavioral contrast is constructed by expanding the coupling coefficient of MPR (Killeen, 1994). The coupling coefficient gives the degree of association of a reinforcer with the target response (as opposed to other competing responses). Competing responses, often identified as interim or adjunctive or superstitious behavior, are intrinsic to reinforcement schedules, especially interval schedules. In addition to that base-rate of competition, additional competing responses may spill over from the prior component, causing initial contrast; and they may be modulated by condit...

Behavior is treated as basic physics. Dimensions are identified and their transformations from physical specification to axes in behavioral space are suggested. Responses are treated as action patterns arrayed along a continuum of activation energy. Behavior is seen as movement along a trajectory through this behavior space. Incentives or reinforcers are attractors in behavior space, at the centers of basins of lowered potential. Trajectories impinging on such basins may be captured; repeated capture will warp the trajectory toward a geodesic, a process called conditioning. Conditioning is enhanced by contiguity, the proximity between the measured behavior and the incentive at the end of the trajectory, and by contingency, the depth of the trajectory below the average level of the potential energy landscape. Motivation is seen as the potential of an organism for motion under the forces impinging on it. Degree of motivation is characterized by the depth of the potential field, with l...

The mechanics of behavior developed by Killeen (1994) is extended to deal with deprivation and satiation and with recovery of arousal at the beginning of sessions. The extended theory is validated against satiation curves and within-session changes in response rates. Anornalies, such as (a) the positive correlation between magnitude of an incentive and response rates in some contexts and a negative correlation in other contexts and (b) the greater prominence of incentive effects when magnitude is varied within the session rather than between sessions, are explained in terms of the basic interplay of drive and incentive motivation. The models are applied to data from closed econ- omies in which changes of satiation levels play a key role in determining the changes in behavior. Relaxation of various assumptions leads to closed-form models for response rates and demand func- tions in these contexts, ones that show reasonable accord with the data and reinforce arguments for unit price as a controlling variable. The central role of deprivation level in this treatment distinguishes it from economic models. It is argued that traditional experiments should be redesigned to reveal basic principles, that ecologic experiments should be redesigned to test the applicability of those principles in more natural contexts, and that behavioral economics should consist of the applications of these principles to economic contexts, not the adoption of economic models as alternatives to behavioral analysis.

Lever pressing by squirrel monkeys was maintained under second-order schedules of either food presentation or IM cocaine injection. Under one second-order schedule, every tenth response produced a brief (l-s) visual stimulus and the first brief stimulus presented after 30 rain had elapsed was followed either by ten 300 mg food pellets or by a 3.0 mg IM injection of cocaine. Under another second-order schedule, the first response after 3 rain produced the brief stimulus and the tenth brief stimulus was followed either by food or by cocaine. The two types of second-order schedules generated distinctly different patterns of responding. Furthermore, the temporal distribution of responding maintained by food presentation or cocaine injection sometimes differed slightly under the same schedule. Food presentation or cocaine injection occurred only at the end of each daily session, thereby allowing assessment of the effects of presession administration of cocaine, chlorpromazine (CPZ), and chlordiazepoxide (CDP) on responding at times when the direct effects of consequent cocaine injections were minimal or absent. Presession treatment with suitable doses of cocaine increased low rates of food-or cocaine-maintained responding under both types of second-order schedules, whereas CPZ only decreased responding. CDP increased responding in some monkeys, whereas in other monkeys it had little or no effect. Individual differences in the effects of CDP were not related to the schedule of reinforcement, the maintaining event, or the control rate of responding. Thus, the behavioral effects of cocaine, CDP, and CPZ were largely independent of whether responding was maintained by food or by cocaine.

The effects of pentobarbital and d‐amphetamine were assessed on key pecking by pigeons under conventional single‐key multiple schedules and under two‐key multiple schedules in which discriminative stimuli appeared on one key (stimulus key) while pecks on a second key (constant key) produced food. Pecks on the stimulus key had no scheduled consequences. A 60‐second variable‐interval schedule operated in one component of each multiple schedule; either extinction or a 60‐second variable‐time schedule operated in the alternate component. When the alternate‐component schedule was extinction, a high rate of responding was maintained in the variable‐interval component of the single‐key schedule; responding on both keys was maintained in the variable‐interval component of the two‐key schedule. Pentobarbital increased responding in the variable‐interval component of the single‐key schedule and increased stimulus‐key, but not constant‐key responding in that component of the two‐key schedule. ...

Reinforcer magnitude and fixed‐ratio requirement were varied under two second‐order schedules. Under one, the first sequence of a fixed number of responses completed after the lapse of a 10‐min fixed interval produced reinforcement. Under the second, a second‐order progressive‐ratio schedule, the fixed number of responses increased after each reinforcement. Either cocaine (0 to 300 μg/kg/inj) or food (0 to 5,700 mg/delivery) reinforcers were delivered. Under some conditions, a 2‐s illumination of stimulus lights occurred on completion of each ratio sequence. Under the second‐order schedule, as cocaine dose or amount of food increased, rates of responding increased; at the highest values, rates of responding decreased. Increases in the ratio requirement from 10 to 170 responses minimally decreased overall response rates. Under the second‐order progressive‐ratio schedule, increases in dose of cocaine or amount of food increased rates of responding; at the highest amounts of food, rate...

Three experiments conducted in an automated ten-compartment chamber recorded col- lateral activities of rats reinforced for lever pressing on differential-reinforcement-of-lowrate schedules. In Experiment 1, the rate of lever pressing increased when stimulus support for collateral activities was removed, thus confirming earlier findings. However, there were no temporal or sequential patterns of collateral activities that predicted operant responding. In Experiment 2, the rate of lever pressing increased only if (a) access to all stimulus sup- port for collateral activities was simultaneously prevented, and (b) the rat was forced to remain in the presence of the lever and food tray. The availability of any of the stimuli related to collateral activity was sufficient to keep lever-pressing rates from increasing. Experiment 3 examined collateral activities under a signaled differential-reinforcementof-low-rate schedule. Preventing access to stimuli supporting collateral activities had little effect on stable lever pressing when the signal was maintained. When the signal was re- moved, collateral activities continued, but lever-pressing rates increased in three of the four rats and rates of food presentation declined in all rats. Hypotheses that collateral activities have (a) a timekeeping or discriminative function, or (b) directly inhibit operant responding were not supported. The results suggest that collateral activities may facilitate operant responding by simply removing the subject from the presence of reinforcementrelated stimuli.

This paper explores the foundational influence of Charles Darwin and Edward Thorndike on the development of behaviorism in psychology. Darwin's theory of evolution by natural selection emphasized adaptation, observable behavior, and environmental influence, encouraging empirical study and challenging dualistic views of mind and body. Thorndike built upon these principles with rigorous experiments, developing the Law of Effect and theories of learning through trial and error. Together, their contributions shifted psychology toward a more scientific and behavior-focused discipline, laying the groundwork for modern learning theory and educational psychology.



















Academic Reference Sheet
Title: Darwin and Thorndike: Foundations of Behaviorism in Psychology
Author: Casey Edwards
Publication Name: Foundations in Psychological Science Series
Journal Name: Healing Voices Journal
Year: 2025
Volume: Volume 1
Issue: Issue 2
Page Numbers: Page 1 (Abstract), Page 2+ (Main Body)
Links / URL:
• https://caseyedwards.substack.com/p/Darwin-and-Thorndike-foundations
• https://www.caseyedwards.com/publications/darwin-thorndike-essay
Research Interests:
• • Trauma-Informed Psychology
• • Addiction and Recovery Studies
• • Narrative Therapy and Expressive Writing
• • Indigenous Rights and Justice (MMIW Focus)
• • Grief, Loss, and Resilience
• • Neurodiversity and Mental Health (e.g., Autism, BPD, ADHD)
• • Existential and Humanistic Psychology

Lever pressing in rats was maintained by continuous and intermittent schedules of food while defecation was monitored. In Experiment 1, reinforcement densities were matched across variable‐ratio and variable‐interval schedules for three pairs of rats. Defecation occurred in all 3 rats on the variable‐ratio schedule and in all 3 rats on the yoked variable‐interval schedule. In Experiment 2, fixed‐ratio and fixed‐interval schedules with similar reinforcement densities maintained lever pressing. Defecation occurred in 3 of 4 rats on the fixed‐ratio schedule and in 4 of 4 rats on the fixed‐interval schedule. Almost no defecation occurred during continuous reinforcement in either experiment. These results demonstrate that defecation may occur during both ratio and interval schedules and that the interreinforcement interval is more important than the behavioral requirements of the schedule in generating schedule‐induced defecation.

Domestication dramatically alters phenotypes across animal species. Standing variation among ancestral populations often drives phenotypic change during domestication, but some changes are caused by novel mutations. In dogs (Canis familiaris) specifically, it has been suggested that the ability to interpret social-communicative behavior expressed by humans originated post-domestication and this behavior is thus not expected to occur in wolves (Canis lupus). Here we report the observation of three 8-week-old wolf puppies spontaneously responding to social-communicative behaviors from an unfamiliar person by retrieving a ball. This behavioral expression in wolves has significant implications for our understanding and expectations of the genetic foundations of dog behavior. Importantly, our observations indicate that behavioral responses to human social-communicative cues are not unique to dogs. This suggests that, although probably rare, standing variation in the expression of human-directed behavior in ancestral populations could have been an important target for early selective pressures exerted during dog domestication.

We report two experiments using a concurrent-chains procedure in which one terminal-link schedule was fixed-interval 8 s and the alternative schedule changed randomly from day to day. In Experiment 1, the alternative schedule varied between 4 s and 16 s according to a pseudorandom binary sequence similar to the one used by . Similar to results with concurrent schedules, pigeons' response allocation in the initial link was most sensitive to the schedules arranged in the current session, although some effect of prior history was evident. Overall sensitivity was lower than for comparable data from steady-state research. In Experiment 2, a unique value between 2 s and 32 s was used for the alternative-schedule delay in each session. Sensitivity levels were similar to Experiment 1 and remained unchanged across 61 sessions of training. For all subjects, sensitivity was greater when the alternative-schedule delay was greater than 8 s compared with when it was less than 8 s. Generalized-matching plots revealed evidence of clustering of data points into two groups for some pigeons, suggesting that a process similar to a categorical discrimination may have at least partly determined response allocation. Overall, this research shows that pigeons' initial-link response allocation can adjust rapidly to frequent changes in the terminal links.

Our research addressed the question of whether sensitivity to relative reinforcer magnitude in concurrent chains depends on the distribution of reinforcer delays when the terminal-link schedules are equal. In Experiment 1, 12 pigeons responded in a two-component procedure. In both components, the initial links were concurrent variable-interval 40 s variable-interval 40 s, and the terminal links were both 20-s interval schedules in which responses were reinforced by either 4 s of grain in one, or 2 s of grain in the other. The only difference between the components was whether the terminal-link schedules were fixed interval or variable intervals. For all subjects, the relative rate of responding in the initial links for the terminal link that produced the 4-s reinforcer was greater when the terminal links were fixed-interval schedules than when they were variable-interval schedules. This result is contrary to the prediction of Grace's (1994) contextual choice model, but is consistent with both Mazur's ( ) hyperbolic value-added model and incentive theory. In Experiment 2, 4 pigeons responded in a concurrent-chains procedure in which 4-s or 2s reinforcers were provided independently of responding according to equal fixed-time or mixedtime schedules. Preference for the 4-s reinforcer increased as the variability of the intervals comprising the mixed-time schedules was decreased. Generalized-matching sensitivity of initial-link response allocation to relative reinforcer magnitude was proportional to the geometric mean of the terminal-link delays.

The effect of stimulus contiguity and response contingency on responding in chain schedules was examined in two experiments. In Experiment 1, four pigeons were trained on two simple three-link chain schedules that alternated within sessions. Initial links were correlated with a variable-interval 30 s schedule, and middle and terminal links were correlated with interdependent variable-interval 30 s variable-interval 30 s schedules. The combined duration of the interdependent schedules summed to 60 s. The two chains differed with respect to signaling of the schedule components: a two-stimulus chain had one stimulus paired with the initial link and one stimulus paired with both the middle and the terminal link, while a three-stimulus chain had a different stimulus paired with the each of the three links. The results showed that the two-stimulus chain maintained lower initial-link responding than the three-stimulus chain. In Experiment 2, four pigeons were exposed to three separate conditions, the two-and three-stimulus chains of Experiment 1 and a three-stimulus chain that had a 3 s delay to terminal-link entry from the middle-link response that produced it. The two-stimulus chain maintained lower initial-link responding than the three-stimulus chain, as in Experiment 1, and a similar initial-link responding was maintained by the two-stimulus chain and the three-stimulus chain with the delay contingency. The results demonstrate that a stimulus noncontiguous with food can maintain responding that is sometimes greater than a stimulus contiguous with food, depending on the response contingency for terminal-link entry. The results are contrary to the pairing hypothesis of conditioned reinforcement.

Pigeons acquired a different four‐response chain each session by responding sequentially on three keys in the presence of a sequence of four colors. The response chain was maintained by food presentation under a fixed‐ratio schedule. Errors produced a brief timeout but did not reset the chain. Each day there were four 15‐minute sessions, with a 10‐minute intersession interval. Cumulative dose‐effect curves for phencyclidine, pentobarbital, and d‐amphetamine were obtained by giving an injection before each of the four sessions; successive injections increased the cumulative dose in equally spaced logarithmic steps. For comparison, non‐cumulative doses of each drug (i.e., doses not preceded by other doses on the same day) were also tested. As the cumulative dose of each drug increased, the overall response rate decreased, the percent errors increased, and there was less within‐session error reduction (acquisition). With phencyclidine and pentobarbital, the rate‐decreasing and error‐in...

The present study investigated the effects of positive and negative GABA A modulators under three different baselines of repeated acquisition in squirrel monkeys in which the monkeys acquired a three-response sequence on three keys under a second-order fixed-ratio (FR) schedule of food reinforcement. In two of these baselines, the second-order FR schedule and the discriminative stimuli for the response sequence were manipulated (''chain-strained'' and ''tandem-strained''). In the third baseline condition, response-independent tail shock was presented during acquisition of the response sequence. All of these baselines maintained high error levels and produced slow rates of acquisition. Under both the chain-strained and tandem-strained conditions, the positive GABA A modulator triazolam (0.0032-0.1 mg/kg) and the negative GABA A modulators ␤-CCE (ethyl-␤-carboline-3-carboxylate; 0.01-1 mg/kg), ␤-CCM (methyl-␤-carboline-3-carboxylate; 0.0032-0.1 mg/kg), and FG -7142 (methyl-␤-carboline-3-carboxamide; 0.18-10 mg/kg) dose-dependently decreased overall response rate compared to administration of saline (control). Under the same two conditions, triazolam and the negative GABA A modulators also increased the percentage of errors; however, the effects on accuracy frequently depended on the baseline condition and the particular modulator. In contrast, triazolam only decreased errors and enhanced acquisition in the presence of concurrent responseindependent tail shock when compared to saline administration under this condition. The neutral GABA A modulator, flumazenil (1 mg/kg), had no effect on rate or accuracy of responding when administered alone, but antagonized the rate-decreasing and error-increasing effects produced by the negative GABA A modulators. Together, these data suggest that the effects of both the positive and negative GABA A modulators on acquisition can be similar in squirrel monkeys (i.e., both types of modulator may produce rate-decreasing and error-increasing effects) and that their effects on acquisition depend, in part, on the environmental conditions maintaining acquisition.

Six rhesus monkeys responding under a three-component multiple schedule were administered haloperidol to determine its effects on cocaine self-administration and on cocaine's disruptive effects on the repeated acquisition and performance of response chains. In the absence of haloperidol, 0.0032-0.032 mg/kg/infusion of cocaine increased response rate and the number of infusions in the selfadministration component when compared to saline administration, whereas 0.1-0.32 mg/kg/infusion decreased response rate and the number of infusions. When compared to saline administration, the two lowest infusion doses of cocaine had little or no effect on responding in the acquisition and performance components; however, higher infusion doses of cocaine dose-dependently decreased response rate in these components. In addition, the higher doses of cocaine also increased the percentage of errors in the acquisition and performance components. Pretreatment with haloperidol (0.0032 or 0.01 mg/kg, i.m.) antagonized the effects of low doses of cocaine on the number of infusions in the self-administration component, whereas only the 0.01-mg/kg dose antagonized the effects of high doses of cocaine on the number of infusions. Neither dose of haloperidol antagonized the ratedecreasing effects of cocaine on responding in the acquisition and performance components significantly; the highest dose of haloperidol alone decreased rates of responding in each component. Antagonism of cocaine's error-increasing effects by haloperidol was only evident at one dose of cocaine (0.032 mg/kg/infusion), and was more complete in the performance components than in the acquisition components. Together, these data show the limited suitability of haloperidol for selectively antagonizing cocaine self-administration in the context of a multiple schedule involving transition behavior, and show the lack of uniform antagonism across operant behaviors.

In one component of a multiple schedule, pigeons were required to complete the same four‐response chain each session by responding sequentially on three identically lighted keys in the presence of four successively presented colors (chain performance). Food presentation occurred after five completions of the chain (i.e., after 20 correct responses). Errors, such as responding on the center or right key when the left was designated correct, produced a brief timeout but did not reset the chain. In the other component, responding on a single key (lighted white) was maintained by food presentation under a fixed‐ratio 20 schedule. In general, phencyclidine and d‐amphetamine produced dose‐dependent decreases in the overall response rates in both components. With pentobarbital, overall rate in each component generally increased at intermediate doses and decreased at higher doses. All three drugs produced dose‐dependent disruptive effects on chain‐performance accuracy. Phencyclidine and pen...

Several researchers have suggested that conditioning history may have long‐term effects on fixed‐interval performances of rats. To test this idea and to identify possible factors involved in temporal control development, groups of rats initially were exposed to different reinforcement schedules: continuous, fixed‐time, and random‐interval. Afterwards, half of the rats in each group were studied on a fixed‐interval 30‐s schedule of reinforcement and the other half on a fixed‐interval 90‐s schedule of reinforcement. No evidence of long‐term effects attributable to conditioning history on either response output or response patterning was found; history effects were transitory. Different tendencies in trajectory across sessions were observed for measures of early and late responding within the interreinforcer interval, suggesting that temporal control is the result of two separate processes: one involved in response output and the other in time allocation of responding and not responding.

The success of behavior-analytic procedures to teach language to individuals with autism spectrum disorder (ASD) has been well established in the literature. Nevertheless, some individuals may not learn any receptive or expressive language following extensive teaching efforts. We examined the effects of two reinforcement contingencies, functional and arbitrary, on increasing the level of auditory–visual conditional discriminations in children with ASD with a history of having difficulty learning discriminations. We evaluated the effects of the reinforcement contingencies by comparing the number of trials needed to establish discriminations in an adapted alternating treatment design. We found that five out of eight participants showed more rapid acquisition and demonstrated discrimination between more items in the functional reinforcement condition. The remaining three participants did not exhibit any discrimination in either condition within the allotted 500 trials/20 days. These fi...

Five-year-old children received training on four symbolic match-to-sample tasks with single-element stimuli (A 1-B1, A2-B2; P1-Q1, P2-Q2). Then they received training on four novel matching tasks with AB compounds as samples and X stimuli as comparisons. The children received positive feedback for selecting X1 when given compounds representing sample-correct comparison relations (A 1 B1-X1, A2B2-X1) and for selecting X2 when given sample-incorrect comparison relations (A 1 B2-X2, A2B1-X2) . Finally transfer from AB-X to PQ-X was assessed (P1 Q1-X1, P2Q2-X1, P1 Q2-X2, P2Q1-X2). Most children did not learn the AB-X tasks unless they were first trained to respond to all compound elements, and they did not reliably show transfer unless they had first learned that the compounds (e.g., A1B1) represented sample-comparison relations (A 1-B 1).

Studies on functional equivalence usually start with the training of multiple conditional discrimination tasks with common stimuli or responses. After retraining one member of each class, transfer across same-class stimuli is assessed. For example, in the study by , preschool children were trained Reprints may be obtained from Paul M. Smeets

Previous research has shown that after training simple discriminations (A1'//A2(/, B1'//B2(/), bringing these tasks under conditional control (J1 Á/A1, J2 Á/A2) leads to transfer of discriminative control (J1'//J2(/) and to generalized matching on the basis of same discriminative functions (e.g. J1 Á/B1, J2 Á/B2). The same occurs when conditional discriminations are trained (D1 Á/E1, D2 Á/E2; F1 Á/G1, F2 Á/G2). When the subjects are then trained to demonstrate correct relations (D1 Á/E1, D2 Á/E2) when given X1 and to demonstrate incorrect relations when given X2 (XD Á/E), transfer of discriminative control (X1'//X2(/) and generalized matching on the basis of same discriminative functions emerges (e.g. X1F1 Á/G1, X2F1 Á/G2). The present study investigated if these performances are dependent on the training and/or testing order. In Experiment 1, the lower-order contingency tasks were trained before the higher-order contingency tasks (A1'//A2(/, B1'//B2(/ before J Á/A, and D Á/E, F Á/G before XD Á/E). Half the subjects received the J Á/B test before the more complex XF Á/G test (Condition A), while for the other subjects, this testing order was reversed (Condition B). Finally, all subjects received additional tests in which they were given the opportunity to demonstrate the discriminative properties of the J and X stimuli (J1'//J2(/, X1'//X2(/), and to match the A, J, and X stimuli with newly introduced stimuli of same discriminative properties (e.g. J1-POLITE, J2-RUDE). Experiment 2 was the same except that the training order was reversed (J Á/A before A1'//A2(/, B1'//B2(/, and XD Á/E before D Á/E, F Á/G). The results were affected by the training order but not by the testing order. Transfer of discriminative functions and generalized matching on the basis of same functions only occurred reliably when the lower-order contingency tasks were trained first. A stimulus-control account of the data is offered.

This research investigated emergent stimulus relations produced by match-to-sample tasks with compound samples and unitary comparisons. The study was a modified replication of the Markham and Dougher study (1993) and consisted of two experiments. Four adults participated in Experiment 1, and 12 6-to 11-year-old children in Experiment 2. Both experiments . involved the same training and testing sequence: Training of four AB-C relations (A 1 B1-C1, A2B2-C1, A 1 B2-C2, A2B1-C2), followed by C-AB tests (symmetry) and BC-A or AC-B tests, C-D training (C1-D1 , C2-D2), D-C tests, D-AB tests (equivalence), and AD-B or BD-A tests. All 16 subjects demonstrated class-consistent C-AB and class-like AC-B or BC-A relations. Of these subjects, 15 also demonstrated classconsistent D-AB and class-like BD-A or AD-B relations. Studies on stimulus equivalence typically use arbitrary match-tosample tasks with single-element stimuli (e.g., Greek letters) as samples and as comparisons. For ease of exposition, these stimuli are commonly denoted by alphanumeric codes (A 1, B2, etc.) with the numerals indicating class membership. In general, these studies show that after being trained on multiple interrelated match-to-sample tasks (e.g., A 1-B1, A2-B2; B1-C1, B2-C2), most verbal humans (normal adults and children, persons with developmental disabilities) relate all same-class stimuli conditionally to one another: B1-

This research investigated emergent stimulus relations produced by match-to-sample tasks with compound samples and unitary comparisons. The study was a modified replication of the Markham and Dougher study (1993) and consisted of two experiments. Four adults participated in Experiment 1, and 12 6-to 11-year-old children in Experiment 2. Both experiments . involved the same training and testing sequence: Training of four AB-C relations (A 1 B1-C1, A2B2-C1, A 1 B2-C2, A2B1-C2), followed by C-AB tests (symmetry) and BC-A or AC-B tests, C-D training (C1-D1 , C2-D2), D-C tests, D-AB tests (equivalence), and AD-B or BD-A tests. All 16 subjects demonstrated class-consistent C-AB and class-like AC-B or BC-A relations. Of these subjects, 15 also demonstrated classconsistent D-AB and class-like BD-A or AD-B relations. Studies on stimulus equivalence typically use arbitrary match-tosample tasks with single-element stimuli (e.g., Greek letters) as samples and as comparisons. For ease of exposition, these stimuli are commonly denoted by alphanumeric codes (A 1, B2, etc.) with the numerals indicating class membership. In general, these studies show that after being trained on multiple interrelated match-to-sample tasks (e.g., A 1-B1, A2-B2; B1-C1, B2-C2), most verbal humans (normal adults and children, persons with developmental disabilities) relate all same-class stimuli conditionally to one another: B1-

In nonhuman animals, the transitive inference (TI) task typically involves training a series of four simultaneous discriminations involving, for example, arbitrary colors in which choice of one stimulus in each pair is reinforced [+] and choice of the other color is nonreinforced [-]. This can be represented as A+B-, B+C-, C+D-, D+E-and can be conceptualized as a series of linear relationships: A>B>C>D>E. After training, animals are tested on the untrained non endpoint pair, BD. Preference for B over D is taken as evidence of TI and occurs because B is greater than D in the implied series. In the present study we trained pigeons using a novel training procedure-a hybrid of successive pair training (training one pair at a time) and mixed pair training (training all pairs at once)-designed to overcome some of the limitations of earlier procedures. Using this hybrid procedure, we trained five premise pairs (A+B-, B+C-, C+D-, D+E-, and E+F-) which allowed us to test three untrained non endpoint pairs (BD, CE, and BE). A significant TI effect was found for most subjects on at least two out of three test pairs. Different theories of TI are discussed. The results suggest that this hybrid training is an efficient procedure for establishing mixed pair acquisition and a TI effect. transitive inference; value transfer; simultaneous discriminations; pigeons Piaget ( , 1955) ) described a transitive inference (TI) task in which a child might be

Adaptation-level (AL) theory qualitatively accounts for several phenomena in the area of aversive behavior: (a) adaptation and contrast effects, (6) the attenuation of an aversive event's effectiveness found when its intensity is gradually increased, and (c) the correspondence of performance to the average reinforcement intensity when the reinforcers vary in intensity. Perceptual effects are sometimes overshadowed by conditioning processes, especially in studies where shock is given before a learning task. It is concluded that AL theory is useful in understanding aversive behavior, although parametric investigations and subsequent quantitative applications of the model are needed.

Following exposure for a minimum of 500 to 600 trials, three of four naive squirrel monkeys eventually pressed a response key, illumination of which always preceded delivery of a food pellet. Three other naive monkeys did not press the key when the pellets were delivered randomly with respect to key illumination. Despite some similarities to auto- shaping using pigeons, the data indicate many points of difference when squirrel monkeys are used as subjects. Although key-food pairings were shown to be important in the acquisition of the key-press response, they were ineffective in maintaining the response when either a negative response-reinforcer dependency was introduced, or when there was no scheduled response-reinforcer dependency (fixed trial). Not all demonstrations of auto- shaping can be considered to be under the control of those processes that are primarily responsible for the phenomena obtained in pigeons. When response-independent food presentations follow brief periods of illumination of a disc, pigeons will reliably peck at the disc. Brown and Jenkins (1968) demonstrated that this phenomenon of autoshaping was depen- dent on "forward pairings" (i.e., key illumination preceding food presentation). "Reverse pairings" (i.e., food presentations preceding key illumination), constant key illumination, and dark key-food pairing procedures yielded minimal responding. The greater relative importance of the key-food, as opposed to the response-food, relationship in the maintenance of such pecking was demonstrated by Williams and Williams (1969). They showed that peck- ing was maintained despite a negative re- sponse-reinforcer contingency such that food was not presented if the pigeon pecked during the trial. Moreover, Gamzu and Williams (1971, 1973) have shown that when food is presented independently of responding, main- tenance, as well as acquisition of pecking, is dependent on a differential association be- tween key and food presentations. A non-

The joint control of rate of key pecking in pigeons by stimulus-reinforcer and response- reinforcer relationships was studied in the context of a two-component multiple schedule of reinforcement. Food presentation was always associated with one component and ex- tinction with the other. The stimulus-reinforcer relationship was manipulated by varying the relative durations of the two components. In the food-presentation component, a fixed rate of reinforcement, independent of rate of responding, was generated by a schedule referred to as "T*". One aspect of the response-reinforcer relationship, contiguity, was manipulated by varying the percentage of delayed reinforcers. With the multiple T ex- tinction schedule, stimulus-reinforcer and response-reinforcer relationships could be varied independently of one another. Rate of key pecking was sensitive to manipulations of both relationships. However, significant differential effects due to either the stimulus-reinforcer or response-reinforcer relationship were obtained only when the other relationship was weak: stimulus-reinforcer and response-reinforcer relationships interacted in the joint control of responding. Key words: stimulus-reinforcer relationship, response-reinforcer relationship, relative component duration, percentage delayed reinforcement, multiple schedule, T schedule, key peck, pigeon Substantial bodies of research have demon- strated powerful control of the pigeon's key- peck response by operant (response-reinforcer) (cf., Ferster and Skinner, 1957; Herrnstein, 1970; Honig, 1966) and respondent (stimulusreinforcer) (cf., Hearst and Jenkins, 1974; Schwartz and Gamzu, 1977) dependencies. Now that the sensitivity of key pecking to both stimulus-reinforcer and response-reinforcer relationships has been established (Hearst and Jenkins, 1974; Schwartz and Gamzu, 1977), the interaction of these two relations becomes a topic of further interest. The joint influence of operant and re- spondent factors in the control of key pecking has been examined in at least two types 'This research was supported by NSF Grant GB 35319X to D. R. Williams. We are grateful to all mem- bers of the Penn Psychology Beer Seminar for helpful discussions of the data. Thanks are also due Douglas

Three naive pigeons were exposed to a series of two‐component multiple schedules of response‐independent food presentation. The component schedules were sometimes identical (non‐differential procedures) and sometimes different (differential procedures). High rates of key pecking were maintained in all the differential procedures, and pecking decreased substantially in non‐differential procedures, even when the frequency of food presentation in non‐differential procedures was higher than in differential procedures. It is suggested that the high rates of key pecking were maintained not by adventitious response‐reinforcer contingencies, but by differential contingencies between the stimulus (keylight) and food. The role of such contingencies in the phenomenon of behavioral contrast is discussed.

The effects of the availability of an alternative reinforcer on responding maintained by food pellets or fluid solutions were examined in 6 adult male baboons (Papio cynocephalus anubis). During daily 23-hr experimental sessions, baboons had concurrent access to both food pellets and fluid, with responding maintained under fixed-ratio schedules of reinforcement that varied between the two commodities. The fixed-ratio requirement, or cost, for pellets was increased when (a) no fluid, (b) a dilute dextrose vehicle, (c) 0.002 mg/kg d-amphetamine, or (d) 0.004 mg/kg d-amphetamine was available. When given nonrestricted concurrent access to food pellets and amphetamine at minimal cost (FR 2), baboons self-administered sufficient amphetamine to decrease pellet intake. Increasing the response requirement for pellets decreased pellet intake at a similar rate regardless of the available fluid and increased fluid intake in a variable manner among baboons such that there were no statistically significant increases in fluid intake. In contrast, when access to pellets was restricted to 70% of maximal intake under nonrestricted conditions, increasing pellet cost decreased pellet intake and increased fluid intake more rapidly when the high amphetamine dose was available. Thus, amphetamine was more effective as an economic substitute for pellets when access to pellets was restricted. The response cost for vehicle and both amphetamine concentrations was increased when baboons had nonrestricted and restricted access to pellets. Increasing the response requirement for fluid delivery decreased intake of all three fluids similarly under both pellet-access conditions. The results indicate that substitution between commodities with minimal commonalities can be studied under controlled laboratory conditions and is dependent upon reinforcement schedule and commodity restrictions.

Six adult male research volunteers, in two groups of 3 subjects each, lived in a residential laboratory for 15 days. All contact with the experimenters was through a networked computer system, and subjects' behavior was monitored continuously and recorded. During the first part of each day, subjects remained in private rooms doing planned work activities, and during the remainder of each day, they were allowed to socialize. Two cigarettes containing active marijuana (2.7% Δ9‐THC) or placebo were smoked during the private work period and the period of access to social activities. Three‐day contingency conditions requiring subjects to engage in a low‐probability work activity (instrumental activity) in order to earn time that could be spent engaging in a high‐probability work activity (contingent activity) were programmed during periods of placebo and active‐marijuana smoking. During placebo administration, the contingency requirement reliably increased the amount of time that sub...

The effects of the availability of an alternative reinforcer on responding maintained by food pellets or drug solutions were examined in 8 adult male baboons (Papio hamadrayas anubis). During daily 23-hr experimental sessions, baboons had access to both food pellets and fluid under a two-choice procedure, in which the response requirement, under a fixed-ratio schedule, differed for the two commodities. There were no restrictions on access to water, which was continuously available from a spout at the rear of each cage. In Experiment 1, the fixed-ratio requirement, or cost, for fluid delivery remained constant while the fixed-ratio requirement for pellets was changed every 2 or 3 days when (a) no fluid, (b) a dilute dextrose vehicle, (c) 0.008 mg/kg per delivery cocaine, (d) 0.016 mg/kg per delivery cocaine, or (e) 0.032 mg/kg per delivery cocaine was available concurrently. In Experiment 1, progressively increasing the response requirement for pellets decreased pellet intake, but for 4 baboons pellet intake at maximum pellet cost was lower when cocaine, compared to the vehicle, was available. Increasing the response requirement for pellets had variable effects on vehicle intake. However, increasing the response requirement for pellets increased intake of at least one dose of cocaine to a greater extent than vehicle in all 8 baboons. Thus, cocaine could be considered a more effective economic substitute than vehicle for pellets. Experiment 2 systematically varied the order in which the response requirements for a pellet delivery were presented and added a control condition in which cocaine doses, yoked to the amount self-administered, were given three times during the session by the experimenter. Again, pellet intake at maximal pellet cost was lower when cocaine, compared to the vehicle, was available. In contrast, experimenter-given cocaine doses did not alter responding maintained by pellets. Thus, the effects of self-administered cocaine on responding maintained by food pellets differed from the effects of experimenter-given cocaine on responding maintained by food pellets.

Animal choices depend on direct sensory information, but also on the dynamic changes in the magnitude of reward. In visual discrimination tasks, the emergence of lateral biases in the choice record from animals is often described as a behavioral artifact, because these are highly correlated with error rates affecting psychophysical measurements. Here, we hypothesized that biased choices could constitute a robust behavioral strategy to solve discrimination tasks of graded difficulty. We trained mice to swim in a two-alterative visual discrimination task with escape from water as the reward. Their prevalence of making lateral choices increased with stimulus similarity and was present in conditions of high discriminability. While lateralization occurred at the individual level, it was absent, on average, at the population level. Biased choice sequences obeyed the generalized matching law and increased task efficiency when stimulus similarity was high. A mathematical analysis revealed that strongly-biased mice used information from past rewards but not past choices to make their current choices. We also found that the amount of lateralized choices made during the first day of training predicted individual differences in the average learning behavior. This framework provides useful analysis tools to study individualized visual-learning trajectories in mice.

Experiment 1 investigated whether training subjects to read words aloud would induce cor- rect written spelling of the words even though spelling had no experimental consequences. Training in reading was followed by a weak increment in correct spelling. Experiment 2 in- vestigated whether overtraining in reading would improve spelling more. Spelling improved as overtraining continued until the subjects spelled all the words correctly. Experiments 3 and 4 investigated the components of overtraining responsible for this improvement in spelling. Initial training in reading followed by repeated opportunities to look at (but not say aloud) the printed words resulted in the same gradual improvement in spelling as seen in Experiment 2. The results were related to Skinner's theory of verbal behavior and to studies of the relationship between speaking and instruction-following in children.

The relation between verbal and nonverbal behavior with common syntactic properties was investigated, using retarded and nonretarded children. Reinforcement was contingent on either verbal or nonverbal responses whereas responses of the other repertoire had no experimental consequences. Changes sometimes occurred in the unreinforced (collateral) repertoire, but they were always changes in the stimulus control of pre-existing topographies. A contingency involving responses of one repertoire never instated new topographies in the collateral repertoire. This suggested that the problem of "cross-modality generalization" should be reformulated to distinguish explicitly between instating new topographies and changing the stimulus control of pre-existing topographies. The result confirmed Skinner's hypothesis about "the same response spoken and heard" and clarified some anom- alies in previous studies.

Experimental animals used in this study were handled in accordance with the Principles of Laboratory Animal Care promulgated by the National Society for Medical Research (Ref. ‐AR70‐18, 20 Nov 61). The opinions expressed in this paper are those of the authors and do not necessarily reflect official Department of Army policy.

Debates about the utility of p values and correct ways to analyze data have inspired new guidelines on statistical inference by the American Psychological Association (APA) and changes in the way results are reported in other scientific journals, but their impact on the Journal of the Experimental Analysis of Behavior (JEAB) has not previously been evaluated. A content analysis of empirical articles published in JEAB between 1992 and 2017 investigated whether statistical and graphing practices changed during that time period. The likelihood that a JEAB article reported a null hypothesis significance test, included a confidence interval, or depicted at least one figure with error bars has increased over time. Features of graphs in JEAB, including the proportion depicting single-subject data, have not changed systematically during the same period. Statistics and graphing trends in JEAB largely paralleled those in mainstream psychology journals, but there was no evidence that changes to APA style had any direct impact on JEAB. In the future, the onus will continue to be on authors, reviewers and editors to ensure that statistical and graphing practices in JEAB continue to evolve without interfering with characteristics that set the journal apart from other scientific journals.

Debates about the utility of p values and correct ways to analyze data have inspired new guidelines on statistical inference by the American Psychological Association (APA) and changes in the way results are reported in other scientific journals, but their impact on the Journal of the Experimental Analysis of Behavior (JEAB) has not previously been evaluated. A content analysis of empirical articles published in JEAB between 1992 and 2017 investigated whether statistical and graphing practices changed during that time period. The likelihood that a JEAB article reported a null hypothesis significance test, included a confidence interval, or depicted at least one figure with error bars has increased over time. Features of graphs in JEAB, including the proportion depicting single‐subject data, have not changed systematically during the same period. Statistics and graphing trends in JEAB largely paralleled those in mainstream psychology journals, but there was no evidence that changes t...