Mental models and probabilistic thinking

This paper outlines the theory of reasoning based on mental models, and then shows how this theory might be extended to deal with probabilistic thinking. The same explanatory framework accommodates deduction and induction: there are both deductive and inductive inferences that yield probabilistic conclusions. The framework yields a theoretical conception of strength of inference, that is, a theory of what the strength of an inference is objectively: it equals the proportion of possible states of affairs consistent with the premises in which the conclusion is true, that is, the probability that the conclusion is true given that the premises are true. Since there are infinitely many possible states of affairs consistent with any set of premises, the paper then characterizes how individuals estimate the strength of an argument. They construct mental models, which each correspond to an infinite set of possibilities (or, in some cases, a finite set of infinite sets of possibilities). The construction of models is guided by knowledge and beliefs, including lay conceptions of such matters as the “law of large numbers”. The paper illustrates how this theory can account for phenomena of probabilistic reasoning.     

A reason for theoretical terms

The presence of nonobservational vocabulary is shown to be necessary for wide application of a conservative principle of theory revision.Support for this research was provided by the Office of Naval Research under contract No. N00014-87-K-0401. We thank Daniel Andler and Clark Glymour for helpful discussion.     

Working with Lesbians,Gays, and Bisexuals: Addressing Heterosexism in Supervision

Heterosexism is a form of multicultural bias that has the potential to harm both clients and supervisees. Supervisors are encouraged to examine their own heterosexist lens as a first step in providing a safe environment in which supervisees can challenge their own heterosexism. The issue of heterosexism is first discussed from an ethical vantage point. The second section of the article examines four facets of heterosexism (discrimination, lack of knowledge, stereotyping, and insensitivity) and how they might be exhibited by the supervisor in the supervision arena. Special topics discussed in this section include: the possible consequences of “coming out” in the supervisory context; the presence of heterosexism in the foundational family systems theory; the need for recognition of the special family characteristics of lesbians, gays, and bisexuals; the value of personal and professional relationships with persons who are gay, lesbian, and bisexual; common heterosexist stereotypes and research that refutes them; and the use of language. The final section of the article offers suggestions for working with supervisees around these issues.     

THE EFFECTS OF CONTINGENT AND NONCONTINGENT ATTENTION ON SELF-INJURY AND SELF-RESTRAINT

Self-restraint and self-injurious behavior (SIB) are two responses that can sometimes be members of the same functional response class (i.e., maintained by the same contingency). In such cases, a single treatment should be effective for both responses. In this investigation, we examined the effects of providing attention (the presumed reinforcer) both noncontingently and contingent upon either SIB or self-restraint. Results were consistent with our hypothesis that both responses were maintained by attention and suggested that noncontingent reinforcement was a potentially effective treatment.