The use of rats as discriminative stimuli

A FREE OPERANT PROCEDURE WAS USED TO DETERMINE WHETHER OR NOT ONE RAT COULD DISCRIMINATE: (1) between the presence and absence of a second rat, and (2) between two other rats of the same species and sex. The subjects were four male Wistar rats. The discriminatory response was a bar press and food was used as reinforcement during training. Although there were wide individual differences in rate of learning, all subjects learned to make both discriminations.     

Changes in Academic Performance in the Junior High School

This study was designed to determine the relationships between changes in academic performance and intellective and non-intellective factors. Seventh grade students attending five junior high schools, who had attended selected elementary schools, were tested with the Personal Values Inventory (PVI), a test of academic motivation, shortly after the first seventh-grade marking period. School marks at that marking period and those received the previous year were procured from a self-report included in the PVI. All students had taken the California Achievement Test Battery and Mental Maturity Test as well as the Scholastic Testing Service Work-Study Skills Test in the sixth grade. Factor analysis identified four factors in both boys and girls: intelligence-achievement, academic motivation, academic plans, and youth-culture involvement. While intelligence was found to be mainly unrelated to the criterion, the non-intellective factors, especially academic motivation, bore significant relationships to the changed performance.     

Attitudes of American Secondary School Students Toward the Use of Intelligence Tests

A national sample of about 5,000 public, 2,600 parochial, and 1,200 private secondary school students were asked whether they thought it fair to use intelligence tests to help make decisions in educational, occupational, and other areas. Results indicated that: (1) anti-test sentiment is neither ubiquitous nor consistent. A considerable number of respondents were in favor of testing, the proportion of respondents favoring tests varied greatly as a function of test context, and some favored tests in one context but disapproved of them in another. (2) Social background and individual difference variables interacted with test contexts. Given two test contexts, these variables may have different effects for each in determining the respondent's approval or disapproval of test usage.     

Superior Students' Occupational Preferences and Their Fathers' Occupations

The relationship between the occupational preferences of 147 superior students and their fathers' occupations was traced over the 4-year period that the students attended high schools in Wisconsin. Analysis of the data indicated that both male and female superior students tended to state vocational preferences at the professional level early in high school and to maintain this preference throughout. Their occupational preferences were generally at a higher level than those of their fathers. There was no trend away from general preferences for work at a professional level toward naming of specific occupations within that level. The results suggest that theories of vocational development that imply that stages are passed through during later adolescent periods do not apply to the superior student population of this study.     

Emotional trauma in rats: Age as a factor in recovery

Old (7 months of age) and young (2 months) male rats were divided into groups matched for spontaneous exploratory activity and for age. Experimental rats in the two age categories were then traumatized by giving them a 90 volt shock to the feet for two sec. on only one occasion. It was shown that nearly all the young rats recovered from the trauma within 5 weeks, as measured by brief exploratory activity and defecation, while at the end of 6 months the old rats still had not recovered. These results point up the greater resiliency of young animals, and the need for caution in the interpreting of research and theories on early experience.     

The effect of the square root of time on continuing perceptual tasks

When an observer is confronted with a stimulus pattern that in some aspect does not change over time, perception of that aspect of the pattern does change. This paper documents several different types of change, all of which progress linearly with the square root of the observing time. Examples are drawn from studies of figurai after-effects, motion after-effects, vigilance, motion neutralization, visibility of the stabilized retinal image, effects of contours on visibility and fluctuations in the perceptual organization of ambiguous figures.     

“Adaptation and repulsion in the figural after-effect” and the psychophysical theory

Data recently presented by Wilson (1965) seem to demonstrate the separate effects of adaptation and of after-effect repulsion during and following continued observation of a curved line. Inasmuch as the experiment was performed without apparent reference to the psychophysical theory of figural after-effects (Taylor, 1962), it is interesting to note that the results on adaptation agree qualitatively with one of the major presuppositions of the theory, and the results on repulsion agree quantitatively with its predictions.