The use of extreme groups to test for the presence of a relationship

Experimenters in psychology frequently investigate the relationship between two variables by selecting extreme groups on the first measure and comparing their mean scores on the second. This paper considers the efficacy of this procedure from the criterion of the power of the statistical tests. Optimal cutting points for the extreme groups are defined, and the power of the difference approach is compared to that of significance tests for the productmoment correlation coefficient.     

A comparison of two psychophysical methods using animals

A discrimination box containing two levers with a light above each was used to train eight rats to press beneath the brighter light for a milk reinforcer. The brighter light was held constant and the comparison light was varied to produce 12 brightness differences. The animals were run under two experimental methods: the block method in which each brightness level comparison was presented for a block of 11 contiguous trials, and the staircase method in which the sequence of brightness comparisons was determined by the correctness of the response on the preceding comparison. The block method produced a smaller differential brightness threshold and a larger change in discrimination performance for stimulus magnitude changes than did the staircase method.     

National-Level Projection for Elementary School Guidance

This paper offers a series of proposals for furthering the development of elementary school guidance. Certain assumptions underlying future action were stated. In proposing a national-level plan to determine the nature and characteristics of guidance in the elementary school, several possibilities were offered as to organizational plans and leadership responsibility. The main proposal offered in this paper discussed functional operations both in the area of research and experimentation as well as in theory construction. Specific areas of investigation were proposed. A position statement was recommended and several features of such a position statement were suggested.     

Limiting the role of the family in discontinuation of life sustaining treatment

In matters of discontinuation of life-sustaining treatment, traditional role of the family to speak on behalf of the incompetent patient is questionable. We explore the reasons why physicians perceive patient autonomy to be transferrable to family members. Principle of patient autonomy may not suffice when futile treatment is demanded and may serve to erode the ethical integrity of medical profession. An enhanced role for bioethics committees is proposed when physicians propose to discontinue life-sustaining treatment against the wishes of the patient or their families.     

Self-Monitoring negative statements

We examined the effects of a self-monitoring program on reducing the frequency of negative statements of a student with mild mental retardation who was enrolled in a self-contained classroom at a middle school. A changing criterion design was used within a multiple baseline design across two classroom periods. Additionally, the frequency of positive statements was reported. The results showed a decrease in the number of negative statements, and an increase in the number of positive statements. Maintenance data collected up to 8 weeks after the program ended indicated that the student continued to emit positive rather than negative statements. The use of this procedure to decelerate undesirable behavior is discussed.     

The substitutability of reinforcers

Substitutability is a construct borrowed from microeconomics that describes a continuum of possible interactions among the reinforcers in a given situation. Highly substitutable reinforcers, which occupy one end of the continuum, are readily traded for each other due to their functional similarity. Complementary reinforcers, at the other end of the continuum, tend to be consumed jointly in fairly rigid proportion, and therefore cannot be traded for one another except to achieve that proportion. At the center of the continuum are reinforcers that are independent with respect to each other; consumption of one has no influence on consumption of another. Psychological research and analyses in terms of substitutability employ standard operant conditioning paradigms in which humans and nonhumans choose between alternative reinforcers. The range of reinforcer interactions found in these studies is more readily accommodated and predicted when behavior-analytic models of choice consider issues of substitutability. New insights are gained into such areas as eating and drinking, electrical brain stimulation, temporal separation of choice alternatives, behavior therapy, drug use, and addictions. Moreover, the generalized matching law (Baum, 1974) gains greater explanatory power and comprehensiveness when measures of substitutability are included.     

Images of black women among anglo college students

Previous research on popular images of women and of minority groups has looked almost solely at images of minority men and of white women. This article presents survey data on images of black women among 256 white non-Hispanic college undergraduates, using a modified Katz/Braly scale. The article explores the nature, distribution, correlates, and emotional evaluations of these images and the implications of these images for black women's lives. Images of black women differed substantially from those of American women in general. Most commonly, black women were characterized as loud, talkative, aggressive, intelligent, straightforward, and argumentative. In addition, students rated positive traits less positive and negative traits less negative when exhibited by black women than by American women in general, apparently because of their expectations for black women's behavior.This paper has benefited from the comments of Verna Keith, Wade Smith, and, most especially, Mary Benin. This research was partially supported by Arizona State University Women's Studies Summer Research Awards Program.     

Negatively biased recall in children with self-reported symptoms of depression

This study investigated differences in depressed and nondepressed children's recall of positively and negatively reinforced behavior. Twenty-six children with self-reported symptoms of depression in the fourth through sixth grades were compared with a matched sample of 26 nondepressed children to determine if there was a negative bias in depressed children's recall. Subjects first generated guesses of the most common associations to each of a series of 40 words. Later, when compared with their nondepressed peers, the children with depressive symptomology were less accurate in recalling which words they had answered correctly and remembered fewer of their own correct responses. They also did more poorly when asked to recall the correct answers that had been provided by the investigator. The two groups did not differ, however, in their recall of which items had been answered incorrectly or in their recall of their previous wrong responses. These results suggest that children with self-reported depressive symptomology do not remember negative experiences more than do nondepressed children; rather, they recall positive experiences less well. Selective forgetting of positively reinforced behavior could be a serious handicap for depressed children in school. It could also play an important role in the maintenance and perhaps even the etiology of depressive symptomatology in children.We wish to thank Bruce Compas for his helpful comments on an earlier draft of this paper.