Effects of deprivation upon counting and timing in rats

Two procedures were used in an investigation of the effects of deprivation upon counting and timing. Under the first procedure, fixed minimum interval (FMI), the rat received liquid reinforcement every time it pressed bar B after having waited a minimum of 5 sec following a press on bar A. Under the second procedure, fixed consecutive number (FCN), reinforcement was delivered every time the rat pressed bar B following a run of at least four consecutive responses on bar A.

Water deprivation was varied over a set of values ranging from 4 to 56 hr. Deprivation had almost no effect on the waiting time in the FMI procedure, or on the number of responses per run in the FCN procedure. With both procedures, increasing deprivation shortened the pause between reinforcement and the next response. In the FCN procedure, the speed with which the runs were executed increased with increasing deprivation, although the number of responses in these runs was relatively unaffected.

     

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.     

Marital counselling: Teaching an eclectic approach

Limited opportunities for training combined with misperceptions about the nature of marital counselling lead to many professionals conducting consultations with couples without training. Where training exists, generally a specific ‘pure’ approach, or a definite brand of eclecticism is taught. The Sheffield Marital and Sexual Difficulties Clinic training course currently aims to give trainees the building blocks for evolving their own brand of eclecticism, or the opportunity to follow a particular approach. Psychodynamic, behavioural and systems theories are highlighted, and the various ways to which these (and other theories) can be used together are examined.     

Direct observation of quality of care in residential settings

Direct-observation procedures were used to objectively and efficiently assess several classes of service provided for individuals residing at two state facilities for the developmentally disabled. Time samples were taken of the condition of the clients' physical environment and of the clients themselves. The ongoing behavior of both clients and staff also was recorded. Each residence was observed at least three times during both regular work hours and evening/weekend hours. Results showed that both facilities scored high in the categories regarding the physical condition of the living areas, as well as the categories concerning the condition of the clients. Greater variability was seen in the data on client and staff behavior. More generally, the results indicate that time-sampling procedures can be used efficiently to collect data on multiple aspects of service delivery for large numbers of individuals.     

Evaluating a computational model of perceptual grouping by proximity

A formal approach to the phenomenon of perceptual grouping by proximity was investigated. Grouping judgments of random dot patterns were made by the CODE algorithm (van Oeffelen & Vos, 1982) and several related algorithms, and these judgments were compared with subjects’ grouping judgments for the same stimuli. Each algorithm predicted significantly more subject judgments than would be expected by chance. The more subjects agreed on how a given dot pattern should be grouped, the more successful was the algorithms’ ability to match the judgments for that pattern. CODE predicted significantly fewer subject judgments than did some of the other algorithms, largely because of its overemphasis on the extent of interactivity among dots as they are being grouped.     

Ingroup Versus Outgroup Perceptions of the Characteristics of High-Risk Youth: Negative Stereotyping1

Adolescents tend to categorize themselves and their peers into discrete ingroups and outgroups. A comparison of ingroup versus outgroup perceptions of the characteristics of high-risk youth was investigated. Based on current stereotype research, we examined the perspective that outgroup members would hold a more extreme stereotype of high-risk youth compared to the perceptions of ingroup members. A total of 955 7th- and 10th-grade southern California adolescents completed a questionnaire regarding the characteristics of their own peer group and a high-risk group. Support was obtained for an extremity of judgement effect. Outgroup youth perceived that their high-risk peers engaged in fewer school and nonschool low-risk activities, more high-risk activities, and greater drug use than did ingroup members. Outgroup members also held perceptions of high-risk youth as less likely to hold a white-collar job than did the ingroup members. The perceptions that adolescents have of these groups may play major roles in their own social behavior. The implications of these results for future tobacco use prevention programs are considered.