Effects of sucrose concentrations on single alternation runway responding in rats

Rats received runway training under alternating reward and nonreward in which rewarded (R) trials provided 32 or 4% sucrose concentration from a drinking tube and nonrewarded (N) trials provided a dry tube or, for half of the rats in the 32% condition, plain water. Both 32 and 4% concentrations yielded faster running on R trials than on N trials; but this effect was reliable only for the 32% condition. Compared to 4% sucrose, 32% sucrose yielded reliably slower running on N trials and unreliably faster running on R trials.     

Structural models and occupational aspirations: Black-white variations among deep-south adolescents

Multivariate techniques for attribute data and the backward elimination procedure developed in regression analysis were utilized in an analysis of the occupational aspirations of deep-south adolescents. An examination of the models constructed revealed that: (1) social class indicators accounted for the largest effect estimates; (2) residence was associated with a smaller, yet statistically significant portion of the variation; and (3) the effect of race was negligible when controls were applied. Application of the most efficient model to black and white subsamples revealed race variations in both composite effect estimates and the rank order of effect estimates. Implications of these findings are discussed in terms of the developmental model of occupational choice and suggestions for further research are presented.     

The development of procedures for identifying competitive behavior in children

This study identified events in the competitive process that could be employed to discriminate between competition and individual, non-social behaviors. When children competed they overtly sought out information on how they were doing vis-à-vis their fellow competitor. In addition, their performance was a function of some competitive contingency: a reward for surpassing another. The procedures developed in this study were designed to manipulate competitive contingencies while observing their effects on task performance and social comparisons. The investigator could thus infer that competition was present when (1) subjects sought out information on how they were doing, as well as how another was doing on comparable tasks during competitive contingencies, and (2) their task performance was a function of the competitive contingency.     

Reinforcement and attraction specifying the effects of affective states

A multiplicative effect of magnitude and proportion of positive reinforcements on attraction and self-rated feelings was examined. Subjects (N = 270) rated their attraction toward persons associated with one of three reinforcement magnitudes (personality similarity, attitude similarity, and personal evaluations) and one of six proportions of positive reinforcements (.00, .20, .40, .60, .80, and 1.00). Results indicated that the slope of the linear attraction function increased and the Y-intercept decreased with increasing magnitude of reinforcement (p < .05). A similar interaction effect was found on the feelings of the subjects (N = 90) in another experiment. The results were interpreted as added support for Byrne's reinforcement-affect model of interpersonal attraction.     

Selective imitation of the passive construction through modeling

Six 4- to 5-yr-old subjects were exposed to five sessions in which an adult model used passive sentences to describe a set of modeling stimuli. Probe stimuli, which the subjects were asked to describe without benefit of modeling and without selective reinforcement were interspersed among modeling stimuli. A matched group of control subjects received probletrials but no modeling trials. Both groups of subjects were subsequently tested on their ability to comprehend active and passive sentence forms. Every subject in the experimental group produced passive sentences on probe trials even though there was considerable variability in the number of passives produced. No control subject produced passives. The modeling procedure increased the comprehension scores of the experimental group above those of the control group though the scores of both groups were above chance. The results were contrasted with earlier studies in which modeling was ineffective in producing passive usage and in which comprehension of the passive was not demonstrated by even older children.