Prediction and the partial understanding of the law of large numbers

We examined people's understanding of the implications of the law of large numbers for prediction of social behavior and abilities. We found that people possess a partial understanding of the law: They sometimes recognize that one can predict more confidently from larger samples, but do not recognize that one can predict more confidently to larger samples. This partial understanding was reflected not only in the predictions subjects made, but also in the explanations they constructed to account for their predictions. It appears that people's intuitions include the notion that increasing the size of the predictor sample of events increases predictability, whereas they do not include the notion that increasing the size of the predicted sample of events increases predictability.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26124/1/0000200.pd

The psychometrics of everyday life

We examined people's ability to assess everyday life correlations such as the degree of agreement that exists for various kinds of evaluations and the degree of consistency that characterizes social behavior from occasion to occasion. We found substantial accuracy for correlation estimates if two conditions were met: (1) subjects were highly familiar with the data in question and (2) the data were highly "codable," that is, capable of being unitized and interpreted clearly. We generally found extreme inaccuracy if either of these conditions was not met. Subjects were particularly inaccurate about correlations involving social behavior: They severely overestimated the stability of behavior across occasions. In addition, even subjects who were statistically sophisticated showed limited appreciation of the aggregation principle, that is, the rule that the magnitude of a correlation increases with the number of units of evidence on which observations are based.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26209/1/0000289.pd

Erwartungsbildung über den Wahlausgang und ihr Einfluss auf die Wahlentscheidung

Erwartungen über den Wahlausgang haben einen festen Platz sowohl in Rational-Choice-Theorien des Wählerverhaltens als auch in stärker sozialpsychologisch orientierten Ansätzen. Die Bildung von Erwartungen und ihr Einfluss auf die Wahlentscheidung ist dabei jedoch ein noch relativ unerforschtes Gebiet. In diesem Beitrag werden anhand von Wahlstudien für Belgien, Österreich und Deutschland verschiedene Fragen der Erwartungsbildung und ihrer Auswirkungen untersucht. Zunächst wird die Qualität der Gesamterwartungen analysiert und verschiedene Faktoren identifiziert, die einen systematischen Einfluss auf die Erwartungsbildung haben. Im zweiten Schritt wenden wir uns den Einzelerwartungen über verschiedene Parteien und Koalitionen zu und finden eine moderate Verzerrung zugunsten der präferierten Parteien und Koalitionen. Dabei kann gezeigt werden, dass der Effekt des Wunschdenkens mit dem politischen Wissen und dem Bildungsgrad abnimmt. Schließlich werden in einem letzten Schritt zwei unterschiedliche Logiken für die Auswirkungen von Erwartungen getestet, das rationale Kalkül des koalitionsstrategischen Wählens zur Vermeidung der Stimmenvergeudung sowie der sozialpsychologisch begründete Bandwagon-Effekt. Das Ausmaß an politischem Wissen scheint dabei eine zentrale vermittelnde Variable zwischen den beiden Logiken zu sein

Motivation and Inference: Self-Serving Generation and Evaluation of Causal Theories.

People tend to be unrealistically optimistic about their likelihood of obtaining desired outcomes and avoiding feared ones. It is proposed that this optimistic bias could be due to two kinds of self-serving inferential processes--self-serving generation of theories and self-serving evaluation of evidence-- and that such processes could be driven by self-protective motivational forces. Study 1 shows that people are very facile at generating causal theories. Study 2 shows that people use this skill to generate self-serving theories favoring their own attributes. When generating theories to explain the outcome of someone's marriage, people tend to enhance the extent to which their own attributes are conducive to happy marriage, and play down the extent to which their own attributes are conducive to divorce. Study 3 replicates these findings with a different outcome, success in professional school, and also shows that these findings are limited to people who care about the outcome. Only those people who plan to attend professional school expect their attributes to be more predictive than other attributes of success in professional school, suggesting that the findings most probably result from motivational forces rather than from unintentional cognitive factors. The remaining studies are concerned with self-serving evidence evaluation. Studies 4 and 5 show that people are more likely to believe evidence indicating that they will be unusually healthy in the future than evidence indicating that they will be unusually unhealthy in the future. It is not possible to determine whether this bias is driven by motivational forces or whether it is due to different prior beliefs about one's future health, because of the difficulty of controlling for prior beliefs. Studies 6 and 7 show that female caffeine consumers are reluctant to believe evidence about the negative effects of caffeine on women's health. Prior beliefs are controlled for in two different ways. Male caffeine consumers, who presumably hold the same prior beliefs about caffeine as do female caffeine consumers, but who are not personally threatened by the evidence, show no reluctance to believe it. and female caffeine consumers are willing to believe the evidence when its implications appear less serious. This suggests that the findings are most probably due to self-protective motivational forces rather than to prior beliefs.Ph.D.Social psychologyUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/160814/1/8600476.pd

Stability and malleability of the self-concept.

The self-concept literature is characterized by a continuing controversy over whether the self-concept is stable or malleable. In this article we suggest that it is both but that the stability observed for general descriptions of the self may mask significant local variation. In this study the social environment was varied by creating a situation in which subjects found themselves to be either very unique or very similar to others. Following this manipulation, subjects responded to a series of self-concept mea-sures. Although the uniqueness and similarity subjects did not differ in the trait terms they used to describe themselves, they did differ systematically in their latency for these judgments, in positivity and negativity of their word associations, and in their judgments of similarity to reference groups. These findings imply that subjects made to feel unique recruited conceptions of themselves as similar to others, whereas subjects made to feel similar to others recruited conceptions of themselves as unique. The results suggest that very general self-descriptive measures are inadequate for revealing how the individual adjusts and calibrates the self-concept in response to challenges from the social environment. Two seemingly contradictory aspects of the self have been emphasized in the empirical self-concept literature. The self has been regarded as a stable and enduring structure that pro-tects itself against change (e.g., Greenwald, 1980; Markus