Sex differences in motor performance of young children: Fact or fiction?

Prepubescent boys and girls who had participated for one or more years in a coeducational physical education program were classified by grade (3, 4, and 5) and year (1977, 1978, and 1979). Scores from the AAHPER Youth Fitness Test were analyzed for differences. Results indicated that females at prepubescent ages may be expected to perform at similar levels to boys of the same age on most test items. While differences were not significant, girls in 1979 were actually better than boys of the same age from the two previous years.     

Backward conditioning in Pavlovian type studies

Authors of almost all learning texts have indicated that unconditional/ stimulus-conditional stimulus (UCS-CS) trials (backward conditioning) utilized in classical conditioning experiments will not result in establishing a conditional response (CR) (excitation). Recently, it has been proposed that backward conditioning can take place although whether UCS-CS trials result in excitation or inhibition has been left unspecified. It is proposed that the diversity of findings can be attributed to inadequate methodology and the use of a classical-instrumental transfer paradigm. When only traditional Pavlovian conditioning studies are examined, the experimental findings suggest that UCS-CS trials will result in inhibition.     

Choice times and Spence's discrimination learning theory

In two experiments, rats acquired brightness discriminations in a free-operant circular runway with two response alternatives. Both individual and group choice times revealed continuous changes that were not apparent in the discrete measure of choice. Two major assumptions of Spence's discrimination learning theory were confirmed: (a) learning is continuous, and (b) discriminative stimuli in simple discrimination tasks of both simultaneous and successive types are compounds with position elements as well as elements from the relevant visual dimension. The distinctive, consistent pattern of learning revealed by the choice-time measure suggests that position habits reflect a learning strategy in which the complex task is learned as a series of simpler ones.     

Laterality effects in the method of triads

The method of triads for psychophysical judgments was analyzed in terms of the unidimensional unfolding model of Coombs (1964). This model predicts laterality effects on the stochastic transitivity of triples for which existing models have been unable to account. An experiment was conducted in which triadic judgments were made on circles differing in area. The results confirmed the stochastic transitivity predictions, but a quantitative formulation of the model proved unsatisfactory.     

Laterality effects in risk preference: A test of portfolio theory

A central assumption in portfolio theory of risk preference is that for games with expected value constant the preference ordering of an individual should exhibit a single peaked preference function. This assumption was tested by determining the level of stochastic transitivity satisfied by triples of pairwise preference proportions among eight gambles. In only a small percentage of cases were the predicted levels of stochastic transitivity not satisfied. It was concluded that the results provided strong support for portfolio theory.     

Motivation in concurrent variable-interval schedules with food and water reinforcers

The lever pressing of four food- and water-deprived rats was reinforced on concurrent variable-interval schedules. Food reinforced one response, and water reinforced the other. Response rates in baseline were higher in the food component than in the water component. After response patterns and body weights had stabilized, the animals were given access to either food only, water only, both food and water, or neither food nor water (baseline) before daily sessions. Giving food before a session decreased per cent time in the food component, decreased overall response rates for food, and increased overall response rates for water. Giving water before a session increased per cent time in the food component, increased overall response rates for food, and decreased overall response rates for water. Giving both food and water before a session resulted in a combination of prefeeding and prewatering effects. More food and more water were consumed when both were available than when only one was available before a session.     

Does school desegregation change occupational goals of Negro males?

Instruments, designed to assess values which affect the motivation to work and aspiration levels, were administered to over 600 Negro male seniors in Texas high schools. Results indicate that the degree and duration of school desegregation these students have experienced, ranging from less than 1 to more than 5 years, have had little effect on work values and occupational aspirations.