A method for determining the aversive threshold in the rat using repeated measures: Tests with morphine sulfate

The procedure described here provides an objective automated technique for the psychophysical assessment of the aversive threshold and allows the animal Ss to serve as their own controls. Sensitivity to drug effects, as well as comparisons between drugs, using the same animals are possible also. Using a rectangular tilt cage, the aversive threshold to grid shock was defined as that intensity avoided 75% of the time. Each shock intensity (30, 60, 90, 120, and 150 microA) was presented for 5 min on one side of the cage and then switched to the other side for 5 min, thereby forcing the animal to sample each shock intensity. Aversive thresholds were determined daily for each rat. The analgesic effects of morphine sulfate were compared to saline. Animals were tested for 3 days at each morphine dose level (2, 4, 8, and 16 mg/kg). Each 3-day morphine series alternated with 3 days of testing under saline. Significant differences were detected between saline and morphine at 4, 8, and 16 mg/kg.     

A comparative study of proprietary and nonproprietary vocational training graduates

Questionnaires were sent to 13,549 graduates of four types of proprietary and nonproprietary vocational training programs in four selected metropolitan areas of the United States. Initial responses were received from 5,215 graduates, a response rate of 38.5%. The survey featured an intensive follow-up to reach and estimate the characteristics of the nonrespondent population. Substantial differences favoring nonproprietary programs were found between proprietary and nonproprietary graduates in terms of economic gains following graduation and expressed satisfaction. Nevertheless, both types of programs were found to be generally effective in producing graduates with marketable skills; post-training salaries were high enough to indicate that the training was cost effective in all except proprietary computer training programs. The results supported several recommendations regarding the necessity for uniform standards of accountability in the regulation of vocational training programs, whether they are public or private.     

Preference and response suppression under different correlations between shock and a positive reinforcer in rats

A lever-press response by rats was reinforced by food in two successively presented types of trial signalled by different discriminative stimuli. When responding was punished by a shock in one type of trial, a groups for which the shock always preceded the reinforcer by .5 sec (positive correlation) showed less suppression in those trials than a group which received the shock and food separated in time (negative correlation). When, in a second experiment, rats were given a choice between food alone in one end of a shuttle box and either positively or negatively correlated shock and food in the other on a concurrent schedule, the group receiving the negatively correlated shock showed a greater preference for the food alone end. On the basis of a third experiment in which a tone was substituted for the shock in the choice situation, it was argued that the effect of correlation was not simply due to the stimulus properties of the shock. A final experiment demonstrated that when shock punishment is administered during extinction of the lever-press response, the rate of extinction is slower if the shock has been previously paired with the food reinforcer. Pairing a shock with food seems to attenuate the intrinsic aversiveness of the shock through Pavlovian counterconditioning.     

Sex-role stereotyping in the United States: Is it changing?

A checklist composed of 66 adjectives was used to measure sex-role stereotypes of college and senior high school students (15- to 21-year-olds) in the University of Kansas area. Three hypotheses were tested: (a) Traditional ways of describing men and women will be very much in evidence, and a strong agreement between the sexes concerning these attributes will exist. (b) Females will stereotype sex roles to a lesser degree than males. (c) Females will value feminine characteristics more positively than masculine characteristics, but males as usual will value masculine characteristics more positively than feminine characteristics. All the hypotheses were supported with a single exception: Male subjects did not differentially value masculine and feminine characteristics.     

Negative set effects in character classification: A response-retrieval view of reaction time

In most current accounts of character classification, emphasis is laid on the role of the positive set. Reanalysis of a previous experiment (Marcel, 1970) showed that in the constant set procedure, as well as the varied set procedure, when consecutive sets of digits are used, latency to negative probes depends on remoteness from the positive set boundary, except when the positive set consists of only one item. Two further experiments showed that in both the constant-and varied-set procedures, latency to individual negative probes decreased with their frequency, except with positive sets of one item. These data indicate that negatives are not usually classified as such merely by default. Some alternative models to Sternberg's are discussed. It is proposed that when he is able to (always with one-item positive sets) the subject will perform a physical match. Otherwise the probe will access its location in long-term memory, associated with which is appropriate response information. The ease of recovery of that information is emphasized as responsible for variation in latencies.     

EEG correlates of cumulative expectancy and subjective estimates of alertness in a vigilance-type task

Occipital EEG was monitored during a slow presentation rate vigilance task. EEG samples were taken for each of 400 task events. The EEG is correlated with increases and decreases in “expectancy” built into the task. Post-trial subjective estimates of alertness parallel the EEG changes. Reaction time to “wanted signals” does not correlate with measures of pre-signal EEG.     

Contrast Effects for Black,White, Male,and Female Interviewees1

The purpose of this study was to investigate whether target applicants of different race and/or sex affected the degree of contrast effect error, in an interview setting. This study was a 2 × 2 × 2 factorial ANOVA design (Preceding Applicants × Race × Sex). Undergraduates (N= 120) were randomly assigned to one of the eight experimental conditions. Each subject viewed and rated three videotaped interview simulations. As hypothesized, results indicated a large contrast effect, i.e., preceding applicant main effect. Furthermore, the results also revealed a significant three-way interaction. The ratings given to all target applicants in the Negative Predecessor condition were equally lenient, while the ratings given to ail target applicants in the Positive Predecessor condition were more variable. The focus of this condition was on the white male target applicant, who received the lowest ratings of any target applicant. Interpretation and suggestions for future research are discussed.     

The Hopelessness Scale for Children: Psychometric properties with normal and emotionally disturbed adolescents

The psychometric properties of the Hopelessness Scale for Children (HSC) were evaluated with a sample of 834 normal adolescents and 93 adolescent suicide attempters. Factor analyses studies revealed two factors with both groups. Internal consistency with item-total score correlations were acceptable, while moderate test-retest reliability was found over a 10-week period with the normal sample. Support for the validity of the HSC was provided via studies with the suicide attempter group in which positive correlations with depression and depressive attributional style were found. Predicted differences between the suicide attempters, an outpatient psychiatric sample, and normal controls were also found. However, some items did not appear to discriminate suicide attempters from controls. Results are discussed in terms of the utility of the HSC with adolescents and adolescent suicide attempters and with regard to differences between child and adult samples in hopelessness.     

The “Black Sheep Effect”: Extremity of judgments towards ingroup members as a function of group identification

The present study proposes an extension to the phenomenon of ingroup favouritism, based on the hypothesis that judgments about ingroup members may be more positive or more negative than judgments about similar outgroup members. It contrasts predictions issued from the complexity-extremity hypothesis (Linville, 1982; Linville and Jones, 1980), from the ingroup favouritism hypothesis (Tajfel, 1982) and from Tesser's (1978; Millar and Tesser, 1986) attitude polarization model. Our main prediction, based on Social Identity Theory, is that judgments about both likeable and unlikeable ingroup members are more extreme than judgments about outgroup members. This phenomenon, coined the Black Sheep Effect, is viewed as due to the relevance that ingroup members'behaviour, as compared to that of outgroup members, has for the subjects' social identity. Three experiments supported our predictions. Experiment I additionally showed that inter-trait correlations were stronger for the ingroup than for the outgroup. Experiment 2 showed that the black sheep effect occurs only when the judgmental cues are relevant for the subjects' social identity, and Experiment 3 showed that levels of information about the target of the judgment were ineffective in generating judgmental extremity. Results are discussed in light of a cognitive-motivational alternative explanation to a purely cognitive interpretation of outgroup homogeneity.