The development of anti-litter behavior in a forest campground

This study evaluates the effectiveness of an incentive procedure designed to induce litter collection in a large forest campground. Children in the campground were offered their choice of a variety of reinforcers for picking up and properly disposing of litter. The procedure resulted in a sharp decline in four types of litter planted in the campground.     

The effects of proportion,strength and value orientation of arguments on decision-making

Presented 120 males and 300 females with a summary of arguments concerning a court case. The information varied in the proportion and strength of arguments for either the defense or the prosecution. Based on the relevant arguments version of the cultural value hypothesis, it was predicted that: (a) proportion of arguments is directly related to subjects' ratings of probability of guilt; (b) fewer arguments are needed to move subjects toward innocence than toward guilt; (c) strong minority defense arguments ate more effective than weak ones in allowing subjects to adhere to their initial value; and (d) strong prosecution arguments result in higher probability of guilt ratings than do weak prosecution arguments. Data supported each of these hypotheses.     

Dyadic peer interaction and task orientation in attention-deficit-disordered children

A sequential observational approach was used to compare peer interactions in 10 mixed dyads of ADD-H and non-Add-H boys and 10 dyads of non-ADD-H boys in laboratory cooperative and school classroom task analogue activities. Mixed dyads were found to have a greater frequency of aggression and less joint activity than control dyads in specific situations. No differences were found for measures of functional attention as measured by frequency, duration, and mean duration of task-oriented behavior. Lag sequential analyses revealed two major sequences that differentiated mixed from normal dyads. These were Verbal Reciprocity (a measure of reciprocal verbal interaction) and Retreat (a measure of social withdrawal following aggression).     

The role of social categorization and perceived source credibility in minority influence

This study was conducted in order to compare the influence of ingroup and outgroup minorities and to assess the role of perceived source credibility in minority influence. The subjects were exposed to the simultaneous majority/minority influence paradigm. Ingroup minorities were more influential than outgroup minorities. Subjects moved toward the minority position in private and toward the majority position in public when the minority was represented by members of the ingroup. On private responses subjects were not affected by outgroup minorities who argued for abortion, and they became more positive toward abortion when outgroup minorities opposed abortion. Final &, ingroup minorities were perceived as more credible than outgroup minorities and greater credibility of minority source was associated with greater attitude change toward the minority position. The superior influence of ingroup minorities held when controlling for source credibility. Overall, the results were highly supportive of social identity theory.     

In defense of the advance specification hypothesis for motor control

Summary Choice reaction times often depend on the relations between the responses that are possible. Rosenbaum, Inhoff, and Gordon (1984) accounted for these effects with an advance specification (AS) hypothesis, according to which subjects prepare for a choice by creating a single motor program with the features shared by the response alternatives; after the choice signal is presented, subjects are assumed to fill in the features that were missing. In a recent article, Heuer (1987) argued that the AS hypothesis cannot account for a number of results that he has obtained. He suggested hat a better hypothesis relies on the idea of programming interactions (PI), according to which programs for alternative responses have mutual facilitative or inhibitory influences, depending on their similarity. Heuer (1987) reported an experiment that was partly consistent with the PI hypothesis and, as implied by him, inconsistent with the AS hypothesis. We show that the results of this experiment, as well as the results of Heuer's earlier experiments, are in fact consistent with the AS hypothesis and inconsistent with the PI hypothesis. We show in addition that there are a number of logical problems with the PI hypothesis which make it a less attractive model of choice than the AS hypothesis.Supported in part by National Science Foundation grant BNS-8710933 and a Research Career Development Award from the National Institutes of Health to the first author.