Effects of social context, reinforcer probability, and reinforcer magnitude on humans' choices to compete or not to compete.

In the first two experiments, subjects' choices to earn points (exchangeable for money) either by competing with a fictitious opponent or by not competing were studied. Buskist, Barry, Morgan, and Rossi's (1984) competitive fixed-interval schedule was modified to include a second response option, a noncompetitive fixed-interval schedule. After choosing to enter either option, the opportunity for reinforcers became available after the fixed-interval's duration had elapsed. Under the no-competition condition, points were always available after the interval had elapsed. Under the competition condition, points were available based on a predetermined probability of delivery. Experiments 1 and 2 examined how reinforcer probabilities and reinforcer magnitudes affected subjects' choices to compete. Several general conclusions can be made about the results: (a) Strong preferences to compete were observed at high and moderate reinforcer probabilities; (b) competing was observed even at very low reinforcer probabilities; (c) response rates were always higher in the competition component than in the no-competition component; and (d) response rates and choices to compete were insensitive to reinforcer-magnitude manipulations. In Experiment 3, the social context of this choice schedule was removed to determine whether the high levels of competing observed in the first two experiments were due to a response preference engendered by the social context provided by the experimenters through instructions. In contrast to the first two experiments, these subjects preferred the 60-s fixed-interval schedule (formerly the no-competition option), indicating that the instructions themselves were responsible for the preference to compete. This choice paradigm may be useful to future researchers interested in the effects of other independent variables (e.g., drugs, social context, instructions) on competitive behavior.     

The selective renaissance of the experimental analysis of human behavior

Two recent articles (Dougherty, Nedelmann, & Alfred, 1993; Hyten & Reilly, 1992) have favorably appraised the growth and health of the experimental analysis of human behavior as a whole. Within the last decade alone, there has been a more than threefold increase in the percentage of human operant papers appearing in the Journal of the Experimental Analysis of Behavior. In the present paper, a more molecular analysis is used, and some concerns are raised about the overall health of the field. The analysis included a determination of the rate at which new authors have appeared, how several areas of research have grown, and a contrast between the proportion of papers appearing in each of several areas of research during the last two decades. Two primary concerns are raised in this paper: (a) The recent growth within the field has been in only three select research areas (general schedule control, reinforcement, and stimulus control), and (b) there is an increasing disparity between the number of papers published in the few areas of research receiving the most attention and the number of papers published in the other areas of research receiving the least attention. Although the experimental analysis of human behavior has made considerable progress in the mere number of publications, these publications have been somewhat limited in scope.     

Generalization of a tactile stimulus in horses.

Using horses, we investigated the control of operant behavior by a tactile stimulus (the training stimulus) and the generalization of behavior to six other similar test stimuli. In a stall, the experimenters mounted a response panel in the doorway. Located on this panel were a response lever and a grain dispenser. The experimenters secured a tactile-stimulus belt to the horse's back. The stimulus belt was constructed by mounting seven solenoids along a piece of burlap in a manner that allowed each to provide the delivery of a tactile stimulus, a repetitive light tapping, at different locations (spaced 10.0 cm apart) along the horse's back. Two preliminary steps were necessary before generalization testing: training a measurable response (lip pressing) and training on several reinforcement schedules in the presence of a training stimulus (tapping by one of the solenoids). We then gave each horse two generalization test sessions. Results indicated that the horses' behavior was effectively controlled by the training stimulus. Horses made the greatest number of responses to the training stimulus, and the tendency to respond to the other test stimuli diminished as the stimuli became farther away from the training stimulus. These findings are discussed in the context of behavioral principles and their relevance to the training of horses.     

Elicited responding in chain schedules.

An omission procedure was employed to study elicited pecking in the first component of a two-component chain schedule. Both components were fixed-interval schedules correlated with colored keylights. The first response following the initial-link schedule produced a second fixed-interval schedule. We studied several fixed-interval lengths in two conditions: a standard response-dependent condition and an omission-contingent condition. The omission-contingent condition differed from the response-dependent condition in that responses during the initial fixed interval terminated the trial (omitting the terminal component and grain). If the terminal component was not omitted, a response following the terminal link's requirement produced 4-s access to grain. Pigeons responded during more than 70% of the initial links in the omission-contingent condition and responded during more than 90% of the initial links in the response-dependent condition. In general, rates of responding were consistent with the percentage data. The responding in the omission condition suggests that there may be elicited pecking, in chain schedules using pigeons, that is not the result of contingent conditioned reinforcement.     

Stimulus generalization, discrimination learning, and peak shift in horses.

Using horses, we investigated three aspects of the stimulus control of lever-pressing behavior: stimulus generalization, discrimination learning, and peak shift. Nine solid black circles, ranging in size from 0.5 in. to 4.5 in. (1.3 cm to 11.4 cm) served as stimuli. Each horse was shaped, using successive approximations, to press a rat lever with its lip in the presence of a positive stimulus, the 2.5-in. (6.4-cm) circle. Shaping proceeded quickly and was comparable to that of other laboratory organisms. After responding was maintained on a variable-interval 30-s schedule, stimulus generalization gradients were collected from 2 horses prior to discrimination training. During discrimination training, grain followed lever presses in the presence of a positive stimulus (a 2.5-in circle) and never followed lever presses in the presence of a negative stimulus (a 1.5-in. [3.8-cm] circle). Three horses met a criterion of zero responses to the negative stimulus in fewer than 15 sessions. Horses given stimulus generalization testing prior to discrimination training produced symmetrical gradients; horses given discrimination training prior to generalization testing produced asymmetrical gradients. The peak of these gradients shifted away from the negative stimulus. These results are consistent with discrimination, stimulus generalization, and peak-shift phenomena observed in other organisms.     

Laboratory measures of aggressive responding in male parolees with violent and nonviolent histories

Males on parole were recruited into a study to determine the external validity of the ©Point Subtraction Aggression Paradigm, a laboratory procedure for measuring human aggressive responding. Subjects were assigned to either a violent or nonviolent group based on their criminal record and the Brown History of Violence Questionnaire. Subjects participated in six 25-min sessions and completed a series of questionnaires. During the laboratory sessions subjects were given two response options: 1) Pressing button A to accumulate points exchangeable for money, and 2) pressing button B which ostensibly subtracted points from another fictitious person. Responding on button B was defined as aggressive since it resulted in the ostensible delivery of an aversive stimulus to another person. Results indicated that the subjects in the violent group emitted significantly more aggressive responses than subjects in the nonviolent group. The two groups also differed on psychometric measures of aggression. This study provides external validity for this laboratory measurement of human aggressive responding, even among males with very similar backgrounds. © 1996 Wiley-Liss, Inc.     

Racial Diversity in U.S. Congregations, 1998–2019

Racially diverse congregations have become an important part of the American religious landscape. We use data from the National Congregations Study (NCS), notably including data from the fourth wave, collected in 2018–2019, to examine 20 years of racial diversity in congregations. We find that racial diversity within congregations has increased substantially between 1998 and 2019. There are more congregations in which no one racial or ethnic group comprises more than 80 percent of the people, congregations’ average diversity level has increased, and the percentage of all-white congregations has declined. Nearly a quarter of evangelical churches now have no one ethnic group constituting more than 80 percent of the people, a rate comparable to what we observe among Catholic churches. Moreover, congregations that meet this 80-percent threshold are more likely to be led by black clergy in 2019 than they were in 1998. We end with a note of caution about concluding that diverse congregations necessarily promote racial justice.     

Worshipping Local? Congregation Proximity,Attendance, and Neighborhood Commitment

Review of Religious Research - The growth of suburban and exurban areas pushed many Americans into commuter lifestyles. People drive automobiles to work, to shop, to play, and presumably to...     

Word concreteness and encoding effects on context-dependent discrimination

In three experiments, we investigated the effects of word concreteness and encoding instructions on context-dependent discrimination in verbal contexts, using Murnane, Phelps, and Malmberg's (1999) ICE (item, context, ensemble) theory as the framework Word concreteness was manipulated within participants, and encoding was manipulated between participants. It was hypothesized that the magnitude of context-dependent discrimination would be affected by both concreteness and encoding instructions. Imagery instructions resulted in context-dependent discrimination for both concrete and abstract word pairs across all the experiments. Context-dependent discrimination was observed under rote instructions for concrete and abstract words, particularly when the same context word was paired multiple times with the targets. The results indicated that context-dependent discrimination is not dependent solely on the use of interactive imagery instructions or on word concreteness.     

Reliability estimates for the immediate and delayed memory tasks

The Immediate and Delayed Memory Tasks are variations of the Continuous Performance Test. While previous research with the tasks has focused on group performance across multiple blocks and sessions, reliability estimates have not been established. We estimated reliability (1) between blocks of a single testing session (N=106), (2) across four sessions within a single testing day (N=20), and (3) across sessions on four consecutive testing days (N=20). Analyses indicated that the primary variable of interest, i.e., commission of errors, showed acceptable reliability within and across testing periods.