The wisdom of collective grading and the effects of epistemic and semantic diversity

A computer simulation is used to study collective judgements that an expert panel reaches on the basis of qualitative probability judgements contributed by individual members. The simulated panel displays a strong and robust crowd wisdom effect. The panel’s performance is better when members contribute precise probability estimates instead of qualitative judgements, but not by much. Surprisingly, it does not always hurt for panel members to interpret the probability expressions differently. Indeed, coordinating their understandings can be much worse.     

Prosocial risk taking and interpersonal regret in children: An individual differences study

The relations between prosocial risk taking (taking a risk to benefit another person; PSRT) and interpersonal regret (regret that one's choices have caused a poor outcome for another person) were examined in 192 children aged 7–9. PSRT was measured by children's choices within a gambling task in which one choice guaranteed participants a good prize whereas the other involved risking this prize to help a peer also win a good prize. Interpersonal regret was assessed within the same task by examining children's change in emotion when they learned they would have won a better prize for a peer had they chosen differently. Performance on this task was also examined in relation to sympathy and resource sharing. Findings indicated that the operationalizations of PSRT and interpersonal regret were meaningful. Children who took a prosocial risk were more generous in a resource sharing task. In some circumstances, children who took a prosocial risk were also more likely to experience interpersonal regret than those who did not take a prosocial risk, indicating that experiencing interpersonal regret may be related to individual differences in prosociality. However, experiencing interpersonal regret did not have a direct effect on subsequent prosocial behavior, when measured by resource sharing. We consider findings in relation to a possible distinction between outcome and process regret and the generalizability of the behavioral consequences of regret.     

The contribution of mentoring to the life skills of youth leaving care in Israel

The goal of this study was to examine the contribution of natural mentoring to the improvement of life skills among youth in care in core areas of education, employment, and avoidance of risk behaviours while controlling for personal characteristics and placement history. The sample includes 174 adolescents in residential care in Israel. Results showed that mentoring duration and mentoring functions including mentor as “role model,” “parental figure,” and “independence promoter” significantly contributed to the prediction of the three life skills above and beyond control variables. This study highlights both the array of meaningful roles mentors play in youth's development of life skills and identifies important practice implications regarding the mechanism by which mentoring relationships contribute to the resilience of adolescents.     

Book Review: Eugenics: A Reassessment. Richard Lynn. Westport,CT: Praeger, 2001, 367 pp., $85.00

Population and Environment -     

A case-study in the clinical epidemiology of psoriatic arthritis: multistate models and causal arguments

In psoriatic arthritis, permanent joint damage characterizes disease progression and represents a major debilitating aspect of the disease. Understanding the process of joint damage will assist in the treatment and disease management of patients. Multistate models provide a means to examine patterns of disease, such as symmetric joint damage. Additionally, the link between damage and the dynamic course of disease activity (represented by joint swelling and stress pain) at both the individual joint level and otherwise can be represented within a correlated multistate model framework. Correlation is reflected through the use of random effects for progressive models and robust variance estimation for non-progressive models. Such analyses, undertaken with data from a large psoriatic arthritis cohort, are discussed and the extent to which they permit causal reasoning is considered. For this, emphasis is given to the use of the Bradford Hill criteria for causation in observational studies and the concept of local (in)dependence to capture the dynamic nature of the relationships.     

Double Book Review: Two Perspectives on Five Cities: Modelling Asian Urban Population-Environment Dynamics,edited by Gayl Ness with Michael Low. Oxford University Press, 2000, 309 pp.

Population and Environment -