The ω-rule

We prove that all proofs in -logic (a first order logic with -rule added) in which -rule is used finitely many times can be turned into proofs in which the -rule is used at most one time. Next, we prove that the word finitely above cannot be changed by the word infinitely.     

Backward induction and beliefs about oneself

According to decision theory, the rational initial action in a sequential decision-problem may be found by ‘backward induction’ or “folding back’. But the reasoning which underwrites this claim appeals to the agent's beliefs about what she will later believe, about what she will later believe she will still later believe, and so forth. There are limits to the ‘depth’ of people's beliefs. Do these limits pose a threat to the standard theory of rational sequential choice? It is argued, first, that the traditional solutions of certain games depend on knowledge which exceeds depth limits, and that these solutions therefore cannot be shown rational in the usual sense. Then, for that related reason even ‘folding back’ solutions of one-person problems cannot be! A revision of our notion of rational choice is proposed, analogous to the reliabilist account of knowledge of Goldman and others, by which this paradox is resolved.     

The helping process in group therapy: A review and discussion

The essential activity of group therapy consists of members taking an interest in each other by asking questions, showing concern, and conveying understanding. When members have not done this it has often been taken as a sign of resistance. A review of the research on helping suggests that there are four social factors that affect assistance giving in groups: 1) ambiguity-often people fail to give help because they are uncertain about who should give it, what should be done, and how it should be done; 2) often help is not given because of the way in which problems are presented; 3) the social comparisons that individuals make affect help-giving; and 4) there are costs associated with providing assistance. This discussion suggests that leaders can facilitate interaction among group members as teachers who clarify and as indirect helpers who redirect concerns back to group members.     

An exploratory study of videotapes of long-term group psychotherapy of outpatients with major and chronic mental illness

This study explored patterns emerging in videotaped sessions of group psychotherapy with seven outpatients of a large mental health facility. The 22 sessions spanned the 12th to 27th months of the group's existence. Group members had long histories (25–50 years) of symptoms characteristic of schizophrenia. Each session was rated on the Group Environment Scale. One session from a group in its earlier stages was also rated on the same instrument to give some indication of baseline patterns. Analyses of changes across the 15 months were not statistically significant. However, some GES subscales, including Cohesion, Independence, and Self-Discovery, showed relatively high mean levels across the 15-month period. These elevations are discussed as suggesting the codevelopment of orientations that have sometimes been viewed as incompatible and unattainable for schizophrenics. Interpreted clinically, the GES patterns help to elaborate recent findings about the relatively good success of long-term group therapy with such populations. The study, although merely suggestive, illustrates the potential for gleaning solid and clinically useful data from group psychotherapy research.The authors would like to thank Drs. Jill Rierdan, Nina Fieldsteel, Joseph Christy, and an anonymous reviewer for their suggestions, Kendra Bryant for serving as the reliability rater, and Janet Eltinge for her skilled videotaping.     

Components of analogical reasoning in a mildly head injured population

This study sought to investigate the effects of mild head injury on a particular type of cognitive ability, verbal analogical reasoning. The performance of 19 individuals with head injuries was compared to a group of 30 control subjects matched for age, education, and gender on 100 verbal analogies. Solution times and error rates were modeled. Unstandardized regression weights for individual subjects were correlated with subjects’ performance on a number of standardized ability tests. Results showed that compared to the control subjects, the head injured subjects: (a) were significantly slower to solve the analogies, and were particularly slow to perform certain processes: encoding/inference and comparison; (b) tended to show greater variability in performance; and (c) had data that had a poorer componential model fit. The data suggest that analogical reasoning is affected by a head injury, and that certain information processes may be responsible for performance deficits.     

The construction of the self: An evolutionary view

Contemporary research on the construction of the self emphasizes the products rather than the process of self-development. Borrowing from the writings of William James and contemporary views of natural selection, we propose a model ofevolutionary self-construction. Grounded in the principles of evolution and the philosophy of pragmatism, evolutionary self-construction proposes a process that guides the seeking of “truth” inpossible selves. According to this view, the self develops in response to uncertainty reduction with the “correct” self identified via the “sentiment of rationality.” Selves presently identified as correct are considered to be “instruments of action” that facilitate the interaction between an individual and the environment. Selected selves can then be developed to one’s best advantage and presented in an optimal fashion. This model helps organize contemporary frameworks around a common theme and embraces affect as a central component in the development of the self. A previous version of this paper was presented at the 98th annual meeting of the American Psychological Association, Boston, MA.     

Differential validity by sex in employment settings

The current study meta-analyzes 59 male-female pairs of validity coefficients obtained during revalidation of the General Aptitude Test Battery (GATB) for evidence of differential validity by sex. Results suggest that general cognitive ability may be slightly more predictive of rated job performance for women than for men in our sample of studies. Moderator analyses examined the effects of occupational sex-dominance and cognitive complexity. Results of these analyses indicate that, in single sex-dominated occupations, tests of general cognitive ability and perceptual ability are more valid for members of the dominant sex, and these differences are more apparent at low-complexity levels. Explanations for the findings are offered in terms of properties of the ratings criterion.An earlier version of this paper was given at the 2nd annual convention of the Society for Industrial and Organizational Psychology, Inc., Atlanta, GA. The authors thank Dave Synk for providing the occupation codes for each study.     

Suggestiveness in photospread line-ups: Similarity induces distinctiveness

The present research examined whether line-ups based on target (‘suspect’) face similarity are biased or suggestive. Four experiments are described in which subjects constructed photographic line-ups by selecting foils similar in appearance to a target. Later, another group of subjects who had not seen the faces before (mock witnesses) were asked to pick out the targets from the line-ups. All four experiments showed that mock witnesses selected the target significantly more often than expected by chance, thereby demonstrating suggestiveness. Three alternative line-up construction methods were also evaluated. In these methods, foil selection was based not only on target similarity but also on similarity with one or more of the other line-up faces. Results showed that alternative line-up targets were not selected significantly more often than chance, suggesting that bias was reduced. An overall analysis showed that the alternative line-ups were significantly less suggestive than target-based line-ups. The results indicate that foil selection procedures that incorporate foil-to-foil similarity produce fairer line-ups than those exclusively based on target similarity.