Effects of social isolation and crowding upon active-avoidance performance in the rat

Male and female Sprague-Dawley rats reared in social isolation and in crowded conditions were tested on their active-avoidance performance. Only males appeared to be affected by the treatments; no housing-condition effect was found on the performance of females. The most severe housing-condition effect was that of social isolation; the isolated males showed impaired acquisition of the avoidance response. We have previously reported diminished adrenocortical flexibility in male isolates, which might account for the present results. A possible failure of the inhibition mechanisms of isolates is also taken into account.     

Long-term Practicals in Chemistry in the First-cycle Engineering Curriculum

In 1974–75 at the K.U.Leuven Project Work as Practicals was started in the first-cycle engineering curriculum aiming at (1) the integration of separate teaching items and 7lpar;2) the integration of theoretical and practical or numerical aspects of those items. After 4 years the evaluation of it was more than satisfactory. The teaching team of the Chemistry course has integrated this system of practicals into their normal chemistry practicals. In this way more students 7lpar;currently only 20%) would be able to profit from the new education curriculum, now called ‘Long-term Practicals’. About 20%of the sophomore student volunteers are working for about 15 hours spread over 5 weeks at a mini-research subject in close contact with the members of the teaching team, using the instruments of the Chemistry Division, reading the literature, writing a report after the practical work, with discussion and evaluation of the work with their team-leader. To make it possible that all the sophomore students (400 students in 1987)could profit from this new education system, the physics, mechanics, mathematics, etc. practicals have to adapt to the same integrated practical system.     

The psychological significance of secondary sexual characteristics in nine- to eleven-year-old girls

82 9-11-year-old girls were seen in order to study the onset of puberty as represented by breast and pubic hair growth. Girls filled out self-report scales, mothers rated their daughters' breast and pubic hair development using schematic representations of the Tanner stages, and height was measured by a nurse practitioner. Breast growth, but not pubic hair growth, was expected to be associated with a positive body image, positive peer relationships, superior adjustment, and the rating of adult roles as important (marriage, children, and careers). These expectations were confirmed for all but the adult role measures. Controlling for pubic hair growth did not alter the findings for breast development. Associations with height also were examined. Height was linked to superior adjustment and career importance. These findings are discussed in terms of possible roles that different pubertal events may play in the self-definitions of young adolescents as well as the meaning of various physical changes to the girl and to others.     

Organization of attack and other behaviors of White King pigeons exposed to intermittent water presentations

Six water-deprived pigeons were exposed to a fixed-time 90-sec water schedule with and without a conspecific target available. Target contacts and the pigeon’s location in the test chamber during the interreinforcement interval were recorded, and the results were compared with those previously obtained with food reinforcement. Prior to target introduction, water-reinforced birds spent more total time in the front near the reinforcer dispenser and less in the rear than food-reinforced birds and, unlike food-reinforced birds, exhibited postreinforcement drinking-like behaviors near the reinforcer dispenser before moving away from that area. With the target available, the level, topography, and duration of target-directed biting pecks were comparable for food- and water-reinforced pigeons. In contrast, the temporal organization of target pecks reflected the different temporal and spatial organizations of behavior prior to target introduction. For both food- and water-reinforced birds, the time between reinforcers at which a bird was spatially situated halfway between the front and rear of the chamber prior to target presentation was positively correlated with the time at which maximum target contact subsequently occurred.     

Research Abstracts

Educational technology research and development -     

Piagetian tasks as readiness measures in mathematics instruction: A critical review

The purpose of this review was to synthesize the research on the relationship between performance on Piagetian tasks of concrete operations and performance on mathematics learning tasks in order to determine whether the Piagetian tasks make useful readiness measures. The research consistently indicates that, while there is a positive correlation between performance on Piagetian tasks and mathematics achievement, many school mathematics tasks can be mastered by children who have not yet developed the reasoning abilities measured by Piagetian tasks. This does not diminish the validity of Piaget's theory, but rather suggests that the kinds of reasoning processes identified by Piaget are not essential in solving many school mathematics tasks.     

The interdependence of language and translational math skills among bilingual hispanic engineering students

The performance of 43 Hispanic engineering and science majors on a task that consists of reading a sentence describing a mathematical relationship between two variables, and then writing an equation describing the relationship, is investigated in both English and Spanish. Results are compared with grade point average and with language proficiency. Comparison of the bilingual group to a monolingual group consisting of 52 engineering and science students shows that performance, as measured by either the mathematical translation task or grade point average, is more strongly correlated with language proficiency for the bilingual group. Clinical interviews conducted with samples from each group reveal large differences in the interpretation of the mathematical task between Hispanics and monolinguals. Suggestions are made for the improvement of the technical education of Hispanics.     

Cross-cultural differences in maternal perceptions of cries of low- and high-risk infants

The tape-recorded cries of low- and high-risk newborn infants were rated by 150 inner-city Anglo-American, Black-American, and Cuban-American mothers during the hospital lying-in period following childbirth. Half of each cultural group was primiparous and half was multiparous. The mothers rated the cries along 4 perceptual and 6 caregiving response scale items. Reliable differences were found between low- and high-risk infant cries on all perceptual responses with the effects of culture and parental experience affecting the degree of differences. Generally, Anglo-American mothers found the cries more distressing, urgent, arousing, and sick sounding than Black-American mothers, while Cuban-American mothers showed similarities to both Black- and Anglo-American mothers depending on the scale items. The ratings on the caregiving response scale items paralleled cultural differences found on the perception scale items and previous reports of the mother-infant interaction patterns of other Anglo-, Black-, and Cuban-American samples. The results are discussed as being important in developing nonethnocentric views of the functional significance of the behaviors of the infant at risk, yet as providing evidence of the cross-cultural significance of the cry sound of the infant at risk.