Positive and Negative Hypothesis Testing by Cooperative Groups

In a rule induction problem positive hypothesis tests select evidence that the tester expects to be an example of the correct rule if the hypothesis is correct, whereas negative hypothesis tests select evidence that the tester expects to be a nonexample if the hypothesis is correct. Previous research indicates the general effectiveness of a positive test strategy for individuals, but there has been very little research with cooperative groups. We extend the analysis of Klayman and Ha (Psychological Review, 1987) of ambiguous verification or conclusive falsification of five possible types of hypotheses by positive and negative tests by emphasizing the importance of further examples following hypothesis tests. In two experiments four-person cooperative groups solved rule induction problems by proposing a hypothesis and selecting evidence to test the hypothesis on each of four arrays on each trial. In different conditions the groups were instructed to use different combinations of positive and negative tests on the four arrays. Positive tests were more likely to lead to further examples than negative tests, and the proportion of correct hypotheses corresponded to the proportion of positive tests, in both experiments. We suggest that positive tests are more effective than negative hypothesis tests in generating further evidence, and thus in inducing the correct rule, in experimental rule induction tasks with a criterion of certainty imposed by the researcher.     

BEHAVIORAL THERAPY DEVELOPMENT AND PSYCHOLOGICAL SCIENCE:

Abstract— An abundance of research from diverse areas of psychological science is potentially relevant to behavioral therapy development research. The National Institute on Drug Abuse of the National Institutes of Health convened a workshop to reinforce the connection between basic behavioral and therapy development research. The articles in this Special Section are the product of this workshop. Several lines of basic behavioral research are described, and implications for the development of behavioral therapies are discussed. This Special Section highlights the notion that strengthening the bond between behavioral therapy development research and basic behavioral science will accelerate the advancement of knowledge about behavior, behavioral change and therapeutic interventions.     

An External Validation of Laboratory Evidence for Earned Dignity

Both theoretical arguments and laboratory evidence indicate that society awards earned dignity (worth) to persons perceived as voluntarily performing praiseworthy behaviors. Laboratory research, as well as common observation, indicates also that society accords an intrinsic dignity unconditionally to all people. On a questionnaire given in class, college students reported increased dignity earned by the Russians from their praiseworthy (i.e., embracing freedom) and voluntary rejection of the attempted coup in 1991. The questionnaire also revealed a general belief in intrinsic dignity. External evidence for earned dignity is shown by increased international support for the Russians after rejection of the coup. This convergence of laboratory and external data validates the laboratory techniques for studying social perception of human dignity.     

Public knowledge,attitudes, and beliefs about homeless people: Evidence for compassion fatigue?

Media reports suggest that the public is becoming impatient with the homeless—that so-called “compassion fatigue” has gripped the nation. This characterization of public sentiment could have important policy consequences—restrictive measures can be justified by growing public impatience, and progressive housing policies seem infeasible within a hostile climate of opinion. But evidence to support the compassion fatigue notion is anecdotal. We examine the issue by tracking the results of public opinion polls and by reporting detailed evidence from a nationwide random-digit dial telephone survey (N=1,507) concerning knowledge attitudes and beliefs about homeless people. To be sure, the public sees homelessness as an undesirable social problem and wants something done about it. However, although the homeless are clearly stigmatized, there is little evidence to suggest that the public has lost compassion and is unwilling to support policies to help homeless people.     

Revisiting university student gender role perceptions

Gender role perceptions of five objects—Ideal Woman, Ideal Man, Most Women, Most Men and Self—were elicited from 3300 university students, 81% of whom were Caucasian, with 7% Hispanic, 6% African-American, and 4% Asian. Profiles of student responses for the five objects provided a comprehensive updating of 1970s research on student gender roles. Women (N= 1842) and men (N= 1148) students generally preferred an androgynous Ideal Woman. Women also preferred an androgynous Ideal Man, but men preferred a masculine sex-typed Ideal Man. Women and men's perceptions of Most Women and Men continued to be sex-typed. Men's self perceptions were androgynous, while women saw themselves as feminine sex-typed. Findings suggest that little change in students' gender role perceptions has occurred in the past 15 years.     

Youth at Risk: Another Point of View

In this rejoinder to Tidwell and Corona Garrett (1994), the authors discuss three important aspects of the term at risk that help to clarify its meaning.     

Controlled attention sharing influences time estimation

A seminal attentional model of time estimation predicts that subjective duration will be positively correlated to the amount of attention given to temporal processing. This prediction holds under prospective conditions, in which one is forewarned that judgments of time will be asked, in contrast to retrospective conditions, in which such judgments are required after the relevant period without any prior warning. In three experiments, an attention-sharing method was used. Subjects were asked to control the amount of attention that they devoted to one or the other component of a dual-task paradigm. The first experiment involved word categorization and reproduction of duration. The following experiments, based on signal detection theory, required discrimination of both the duration and the intensity of a single stimulus, in the visual (Experiment 2) or the auditory (Experiment 3) modality. The results indicate that when the attention is directly controlled by the subject, the subjective duration shortens as the amount of attention devoted to the temporal task diminishes. The implications of these results for the possible existence of an internal timer are considered.     

The Role of Affect and Worldviews as Orienting Dispositions in the Perception and Acceptance of Nuclear Power1

Recent research in risk perception has examined the role of affect and worldviews as orienting dispositions that guide people's decisions about complex and risky topics such as nuclear energy. This study tests and supports the hypothesis that worldviews and affect-laden imagery are highly predictive of perceptions of risk from nuclear power and support for that technology. Furthermore, affect and worldviews each contribute independently to the prediction of nuclear support. We find also that a person's affective imagery associated with nuclear power is systematically related to their worldviews. We conclude that affect and worldviews appear to play similar roles as orienting mechanisms, helping people navigate in a complex, uncertain, and sometimes dangerous world. The implication of this view for the practice of risk communication is briefly discussed.