Adult age differences in the realism of confidence judgments: overconfidence, format dependence, and cognitive predictors

Realistic confidence judgments are essential to everyday functioning, but few studies have addressed the issue of age differences in overconfidence. Therefore, the authors examined this issue with probability judgment and intuitive confidence intervals in a sample of 122 healthy adults (ages: 35-40, 55-60, 70-75 years). In line with predictions based on the na?ve sampling model (P. Juslin, A. Winman, & P. Hansson, 2007), substantial format dependence was observed, with extreme overconfidence when confidence was expressed as an intuitive confidence interval but not when confidence was expressed as a probability judgment. Moreover, an age-related increase in overconfidence was selectively observed when confidence was expressed as intuitive confidence intervals. Structural equation modeling indicated that the age-related increases in overconfidence were mediated by a general cognitive ability factor that may reflect executive processes. Finally, the results indicated that part of the negative influence of increased age on general ability may be compensated for by an age-related increase in domain-relevant knowledge.     

The transportability of multisystemic therapy to Sweden: short-term results from a randomized trial of conduct-disordered youths

This randomized clinical trial assessed the effectiveness of multisystemic therapy (MST) for 156 youths who met the diagnostic criteria for conduct disorder. Sweden's 3 largest cities and 1 small town served as the recruiting area for the study. A mixed factorial design was used, with random allocation between MST and treatment as usual groups. Assessments were conducted at intake and 7 months after referral. With an intention-to-treat approach, results from multiagent and multimethod assessment batteries showed a general decrease in psychiatric problems and antisocial behaviors among participants across treatments. There were no significant differences in treatment effects between the 2 groups. The lack of treatment effect did not appear to be caused by site differences or variations in program maturity. MST treatment fidelity was lower than that of other studies, although not clearly related to treatment outcomes in this study. The results are discussed in terms of differences between Sweden and the United States. One difference is the way in which young offenders are processed (a child welfare approach vs. a juvenile justice system approach). Sociodemographic differences (e.g., rates of poverty, crime, and substance abuse) between the 2 countries may also have moderating effects on the rates of rehabilitation among young offenders. (PsycINFO Database Record (c) 2008 APA, all rights reserved).     

Revising Probabilities and Full Beliefs

Journal of Philosophical Logic - A new formal model of belief dynamics is proposed, in which the epistemic agent has both probabilistic beliefs and full beliefs. The agent has full belief in a...     

Blockage Contraction

Blockage contraction is an operation of belief contraction that acts directly on the outcome set, i.e. the set of logically closed subsets of the original belief set K that are potential contraction outcomes. Blocking is represented by a binary relation on the outcome set. If a potential outcome X blocks another potential outcome Y, and X does not imply the sentence p to be contracted, then Y?≠?K ÷ p. The contraction outcome K ÷ p is equal to the (unique) inclusion-maximal unblocked element of the outcome set that does not imply p. Conditions on the blocking relation are specified that ensure the existence of such a unique inclusion-maximal set for all sentences p. Blockage contraction is axiomatically characterized and its relations to AGM-style operations are investigated. In a finite-based framework, every transitively relational partial meet contraction is also a blockage contraction.     

European Public Deliberation on Brain Machine Interface Technology: Five Convergence Seminars

We present a novel procedure to engage the public in ethical deliberations on the potential impacts of brain machine interface technology. We call this procedure a convergence seminar, a form of scenario-based group discussion that is founded on the idea of hypothetical retrospection. The theoretical background of this procedure and the results of five seminars are presented.     

AGM 25 Years

The 1985 paper by Carlos Alchourrón (1931–1996), Peter Gärdenfors, and David Makinson (AGM), “On the Logic of Theory Change: Partial Meet Contraction and Revision Functions” was the starting-point of a large and rapidly growing literature that employs formal models in the investigation of changes in belief states and databases. In this review, the first twenty-five years of this development are summarized. The topics covered include equivalent characterizations of AGM operations, extended representations of the belief states, change operators not included in the original framework, iterated change, applications of the model, its connections with other formal frameworks, computatibility of AGM operations, and criticism of the model.     

Finite Contractions on Infinite Belief Sets

Contractions on belief sets that have no finite representation cannot be finite in the sense that only a finite number of sentences is removed. However, such contractions can be delimited so that the actual change takes place in a logically isolated, finite-based part of the belief set. A construction that answers to this principle is introduced, and is axiomatically characterized. It turns out to coincide with specified meet contraction.     

Field-dependence/independence: ability in relation to mobility-fixity

Previous authors have pointed out that, while the classic Rod-and-Frame Test (RFT) yields a measure of ability to perform field-independently, it is unsuitable for identifying stylistic preference, such as mobility-fixity within the field-dependence/independence dimension. To relate mobility-fixity and ability aspects of field-dependence/independence, we compared data obtained from two versions of the test: one with a "free" instruction, on which the subjects were invited to adjust the rod to any position(s) they preferred on each of 10 trials and a process-oriented version (RFT-P), involving 20 trials with the standard instruction but with a constant rod-and-frame configuration, making possible analysis of the process of adaptation. Mobility versus fixity was defined in terms of more or less frequent changes of rod positions and choice of a high or a low proportion of nongeometrical positions in the RFT-Free. 38 female and 23 male university students completed first the RFT-Free and thereafter the RFT-Process. Women were more field-dependent than men throughout the RFT-Process trials; there were no differences between the sexes over trials or in choice of positions in the RFT-Free. Compared with field-dependent subjects, field-independent subjects more often changed rod positions in the RFT-Free and preferred nongeometrical positions somewhat more. Among field-independent subjects, those with consistently low deviations in RFT-Process more often preferred a variety of nongeometrical positions in RFT-Free than did those with gradually increasing deviations. We conclude that field-independence is associated with mobility and field-dependence with fixity, as defined by the RFT-Free variables, and that a prerequisite for high mobility is a relative stability of field-independence as reflected on the RFT-Process. Theoretical implications of this conclusion are discussed.