Game Theory and Rational Decision

In its classical conception, game theory aspires to be a determinate decision theory for games, understood as elements of a structurally specified domain. Its aim is to determine for each game in the domain a complete solution to each player's decision problem, a solution valid for all real-world instantiations, regardless of context. “Permissiveness” would constrain the theory to designate as admissible for a player any conjecture consistent with the function's designation of admissible strategies for the other players. Given permissiveness and other appropriate constraints, solution sets must contain only Nash equilibria and at least one pure-strategy equilibrium, and there is no solution to games in which no symmetry invariant set of pure-strategy equilibria forms a Cartesian product. These results imply that the classical program is unrealizable. Moreover, the program is implicitly committed to permissiveness, through its common-knowledge assumptions and its commitment to equilibrium. The resulting incoherence deeply undermines the classical conception in a way that consolidates a long series of contextualist criticisms. This revised version was published online in July 2006 with corrections to the Cover Date.     

Confirmatory factor analysis of The Aggression Questionnaire

A confirmatory factor analysis of the factor structure of The Aggression Questionnaire created by Buss and Perry (1992) [Journal of Personality and Social Psychology, 63, 452–459] was conducted to assess whether the scale's purported 4 factors emerged. The results generally supported the 4-factor model. However, the hostility factor may be improved if 2 items pertaining to suspicion are removed from the scale. These items had relatively low loadings on that factor and decreased the hostility scale's internal reliability.     

A possible genetic basis of accuracy in personality perception

An analysis was conducted to assess whether individuals are more accurate in perceiving those personality characteristics of other' that have a larger genetic component. Adult monozygotic (MZ) twins (63 pairs) and same-sex dizygotic (DZ) twins (35 pairs) completed the Personality Research Form-E (PRF) and the Sibling Evaluation of Personality Characteristics (SEPC) which consists of 20 sets of adjectives corresponding to the 20 trait scales of the PRF. Subjects also evaluated their co-twin with the SEPC. Self-other agreement correlations were then correlated with the heritability estimates of the PRF traits calculated on the same twin sample. The results suggest that accuracy in perceiving the co-twin's personality does increase with the heritability component of the personality dimension.     

On the naming of color words and color patches

Subjects can name color words faster than they can name color patches. To account for that effect, a generic model of naming is described which assumes that words access the mental lexicon directly, whereas color patches do so only indirectly via an initial imaginal or semantic representation. However, Lund (1927) reported that the naming advantage for words disappeared when all the items to be named on a page were the same (i.e., they were blocked). In the present study, three experiments are reported that were designed to provide a clearer empirical definition of Lund’s blocking effect and to ascertain the extent to which it requires a modification of the generic model. The blocked lists had 50 items arranged into 10 blocks, with each block homogeneous with respect to color. The block lengths were either all a predictable length of 5 items or they varied randomly from 1 to 9 items. The data indicated the following: (1) The blocking effect occurred even when the task required a full identification of each item, and (2) the blocking effect was confined to within-block transitions. Blocking seemed to eliminate the word advantage by allowing the subject to re-use the lexical entry used for the immediately prior item, which is consistent with the generic model.     

Challenges confronting cross-sex friendships: “Much ado about nothing?”

This research was an investigation into four challenges purported to confront cross-sex friends. One hundred and thirty eight individuals (females = 86, males = 52) completed two surveys designed to explore the extent to which the sexual, emotional bond, audience, and equality challenges were present in their cross-sex friendships. Over 98% of the participants were heterosexual, 99% were Caucasian, and approximately 5% were Hispanic. Data gathered from the first survey were analyzed using a three-way analysis of variance, with gender, type of friendship, and romantic status as the independent variables, and three of the four challenges as the dependent variables. The first survey also included open-ended questions designed to explore the nature and existence of the challenges. The second survey was in a diary format. Respondents kept a frequency count for three weeks of discussions they had with their cross-sex friend concerning the challenges, and thoughts that they had as individuals concerning those challenges. Results from both surveys indicate that though the challenges exist and have powerful effects on a small percentage of individuals in cross-sex friendships, for the majority of participants the challenges are not perceived as salient.     

Gts and interrogative tableaux

A variant of the standard deductive tableau system is introduced, and interrogative rules are added, resulting in a so-called interrogative tableau system. A game-theoretical account of entailment is sketched, and the deductive tableau system is interpreted in these terms. Finally, it is shown how to extend this account of entailment into an account of interrogative entailment, thereby providing a semantics for the interrogative tableau system.     

Human sensitivity to temporal proximity: The role of spatial and temporal speed gradients

Estimates of temporal proximity (sometimes called time-to-collision) from random-dot flow patterns are shown to be based upon retinal speed, rather than upon changes in dot density. Neither the spatial nor the temporal gradient of motion is essential to the task, but estimates can be made from either alone. Performance is unaffected by the addition of rotational motion, suggesting that observers axe capable of extracting the radial component of motion, which contains all the relevant information, from complex stimuli.     

Gender and aggression II: Personal aggressiveness

To investigate how gender, ethnicity, age and education influence aggressiveness, we surveyed 115 male and female college students (56% male; 50% Anglo and 26% Hispanic) and 79 persons (72% male; 92% Anglo) working on a military base. Participants were administered the Buss-Perry Aggression Questionnaire and asked about their own aggressive behaviors. In both samples, men scored significantly higher than women on the Physical Aggression scale of the Aggression Questionnaire but not on the other scales. In the military sample, men indicated that they expected to behave more aggressively than women. Positive correlations among different aspects of aggressiveness were found for both men and women. Increasing age and education were associated with lower aggressiveness in both genders, suggesting that aggressiveness may be susceptible to modification over the course of one's life.We would like to thank Angela Bennett, Gail Bliss, Kayleigh Carabajal, Julie Depree, Carmen Gonzales, Deborah Good, Scott Griffin, Gladys Herrera, George Selix, Ruth Tangman, and Jon Woodland for their assistance with the development, distribution, and coding of the questionnaire.     

Beliefs about stories: Parents' and therapists' explanations of childhood difficulties

Therapists and parents were given vignettes describing the behavioural and emotional difficulties of two nine-year-old children and were asked to rate the importance of a number of possible explanations for such difficulties. Broad agreement was found between parents and therapists, but also there were a number of significant differences. Parents endorsed more child centered explanations and put greater emphasis on physical and developmental factors, while therapists endorsed relationships factors and saw the beliefs of other family members as important. Therapists who were parents showed a pattern of responses that lay between those of parents and non-parent therapists.     

Progressive changes in articulatory patterns in verbal apraxia: A longitudinal case study

This research reports findings in a 10-year study of an apraxic adult, who was one of five subjects described by Shankweiler and Harris, (Cortex, ,2 277–292, 1966). Confusion matrices and feature analysis were used to compare 1965 and 1975 performances. Results indicate that over the 10-year period, errors of place, manner, and omission were markedly reduced. Voicing errors, however, while reduced in total number, still constituted a significant percentage of the patient's residual errors. Implications of these findings are discussed.