Differential reinforcement of lever-press durations: Effects of deprivation level and reward magnitude

Three experiments investigated the performance of rats on a task involving differential reinforcement of lever-press durations. Experiment 1, which employed a discrete-trials procedure, manipulated deprivation level between subjects and reward magnitude within subjects. The minimum lever-press duration which would result in reward was varied from .4 to 6.4 sec. It was found that low deprivation resulted in longer mean durations and less response variability at the higher criterial values than did high deprivation. The magnitude of reward was not found to affect performance. Experiment 2 manipulated reward magnitude between subjects while holding deprivation level constant, and used the same general procedures as in Experiment 1. Small reward resulted in longer mean lever-press durations and less variability in responding than did large reward at the higher criterial values. The intertrial intervals were omitted in Experiment 3 in which deprivation level was varied between subjects and reinforcement was delivered only for response durations extending between 6.0 and 7.6 sec. Low deprivation resulted in longer mean lever-press durations and less response variability than did high deprivation, but the probability of a rewarded press duration did not differ between groups. The results overall are consistent with the hypothesis that low deprivation and small reward magnitude lead to weaker goal-approach responses and, hence, to less competition with lever holding. The deprivation and reward magnitude manipulations did not appear to influence lever holding performance by affecting the ability of animals to form temporal discriminations.     

Apparent impropriety and procedural fairness judgments

Variation in decision making and allocation procedures has been shown to affect judgments of the fairness of the procedure and its outcome, but such effects have always been studied in the context of properly enacted procedures. It was hypothesized that the appearance of impropriety in the enctment of a fair procedure would increase the extent to which the procedure is judged in terms of its outcome. One hundred twenty undergraduate males and females were placed in the role of either defendant or observer with respect to an adversary procedure trial. Appearance of impropriety was manipulated during the trial by either including or not including evidence of a friendly personal relationship between the judge and the plaintiff's lawyer. The defendant was said to have either won or lost the case. A significant impropriety × outcome interaction on ratings of procedural fairness, unqualified by higher order effect, supported the hypothesis: a favorable outcome increased and an unfavorable outcome decreased the fairness of the procedure more when the impropriety was present. Discussion focuses on the implications of these findings for future investigation and theory on procedural justice and for practical issues.     

Statistical analysis of binary relational data: Parameter estimation

Binary interaction data, measuring the presence or absence of a relation between pairs of actors in a “dyadic interaction situation,” are commonly gathered to study the social structure of the group of actors. Recent developments have made the statistical analysis of such data statistically easier and more substantively sophisticated. These developments allow researchers to simultaneously study several sociometric structural properties, such as reciprocity, differential popularity, and equivalence of actors. Building on this research, we review the stochastic models responsible for this breakthrough, and discuss methods for estimating expected values and model parameters. Throughout, we also highlight recent advances designed to incorporate nodal or actor attribute data into the relational data analysis. We conclude with an example illustrating these ideas based on conversational activities among actors in a group of eight people.     

The professionalization of psychologists as court personnel: Consequences of the first institutional commitment law for the “feebleminded”

The first law providing for the permanent, involuntary institutionalization of “feeble‐minded” individuals was passed in Illinois in 1915. This bill represented the first eugenic commitment law in the United States. Focusing on the consequences of this 1915 commitment law within the context of intelligence testing, eugenics, and the progressive movement, this paper will argue that the then newly devised Binet–Simon intelligence test facilitated the definition and classification of feeble‐mindedness that validated feeble‐mindedness theory, enabled the state to legitimize the eugenic diagnosis and institutionalization of feeble‐minded individuals, and especially empowered psychologists to carve out a niche for themselves in the courtroom as “experts” when testifying as to the feeble‐mindedness of individuals.     

Electrophysiological correlates of adult decisions made during a conservation of quantity task

Visual evoked responses were recorded from 10 scalp locations over the left and right hemisphere while adults were involved in a conservation of quantity task. Multivariate analyses involving principal components analysis and ANOVA identified bilateral and left hemisphere lateralized components of the visual evoked responses which discriminated between conservation judgments made by subjects.     

Pre- and Postintervention Factor Analysis of the Illinois Rape Myth Acceptance Scale

The effects of a bystander education intervention program on the factor structure underlying a rape myth acceptance scale were examined using exploratory factor analyses on secondary data. The Illinois Rape Myth Acceptance Scale was administered to college students at a northwestern university both before (n = 363) and after (n = 352) receiving a bystander education program. Results from exploratory factor analyses showed changes in the factor structure from pretest to posttest. This suggests some instability in the factor structure of the Illinois Rape Myth Acceptance Scale. These pre–post intervention differences in the rape myth acceptance factor structure suggest researchers use caution in using and interpreting scores based on the IRMA without regard to participants’ prevention program status.     

A recognition test of vocabulary using signal-detection measures,and some correlates of word and nonword recognition

In the first of three experiments, university undergraduates were presented a list of 300 words and 100 nonwords in two sessions. Their confidence that an item was a word was indicated for each item on a 6-point scale. This experiment demonstrated the feasibility of creating a recognition test of vocabulary. In Expeiment II, 100 items were chosen to form a subtest, and the subtest was cross-validated on a new sample of subjects. The tests in Experiments I and II were scored using signal-detection measures. The primary criterion, SAT (verbal) scores, correlated approximately .60 with the test scores. In Experiment III subjects scaled the words and nonwords for four psychological attributes. These were submitted to a stepwise regression with the confidence ratings from Experiment I as the dependent variable. It was concluded that associability. frequency, orthography, and pronounceability all may be components of word recognition. However, only frequency was found to be a significant predictor of the confidence of recognition of nonwords.