Base rates are vital in predicting violent criminal recidivism. However, both lay people given simulated prediction tasks and professionals milking real life predictions appear insensitive to variations in the base rate of violent recidivism. Although there are techniques to help decision makers attend to base rates, increased decision accuracy is better sought in improved actuarial models as opposed to improved clinicians.

Two predictions concerning the perceived severity of crimes can be derived from evolutionary theory. The first, arising from the theory of inclusive fitness, is that crimes in general should be viewed as more serious to the degree that the victim is genetically related to the perpetrator. The second, arising from the deleterious effects of inbreeding depression, is that heterosexual sexual coercion should be perceived as more serious the closer the genetic relationship of victim and perpetrator, particularly when the victim is (...) a female of fertile age. Two hundred and thirty university students estimated the magnitude of the severity of brief crime descriptions in three separate studies. In the first two, the biological kinship of victim and perpetrator was varied, and in the third, the hypothetical genetic relatedness of the subject and the fictitious victim was varied. All three studies found the linear relationships between biological kinship and perceived crime severity predicted by theory. (shrink)

Recent evidence that psychopathy is a nonarbitrary population, such that the trait may be categorical rather than continuous, is consistent with Mealey's distinction between primary and secondary psychopaths. Thus, there are likely to be at least two routes to criminality, and psychopathic and nonpsychopathic criminals are likely to respond differently to interventions.

The well-established finding that siblings growing up in the same family turn out to be very different from one another has puzzled psychologists and behavior geneticists alike. In this theoretical note we describe the possible ontogeny and phylogeny of a sibling differentiation mechanism. We suggest that sibling competition for parental investment results in sibling differentiation on a number of characteristics, producing different developmental trajectories within families. Variations in developmental trajectories within families may have had fitness advantages in ancestral environments because(a) (...) sibling competition for extrafamilial resources would be reduced and(b) these variations would be suited to environments containing a variety of niches or to changing environments. Predictions derived from this model and an example of an application to attachment theory are presented. (shrink)

High mating effort and antisocial and delinquent behaviors are closely linked. Some delinquent behaviors may honestly signal genetic quality. Men who exhibit high mating effort and who have high genetic quality would be expected to engage in more sexual coercion than other men because its costs to them are lowered by female preferences for them as sexual partners.

Trivers’s theory of parental investment suggests that adults should decide whether or not to invest in a given infant using a cost-benefit analysis. To make the best investment decision, adults should seek as much relevant information as possible. Infant facial cues may serve to provide information and evoke feelings of parental care in adults. Four specific infant facial cues were investigated: resemblance (as a proxy for kinship), health, happiness, and cuteness. It was predicted that these cues would influence feelings of (...) parental care for both sexes, but that resemblance would be more important for men than women because of the importance of paternity uncertainty in the ancestral environment. Seventy-six men and 76 women participated in a hypothetical adoption task in which they made judgments of infant faces. Average zero-order, partial, and component score correlations all revealed that men placed primary emphasis on cues of resemblance, while women placed primary emphasis on cues of health and cuteness (cues of infant quality). The correlations also showed that men placed a significantly greater emphasis on cues of resemblance than did women. (shrink)

Infant facial characteristics may affect discriminative parental solicitude because they convey information about the health of the offspring. We examined the effect of Fetal Alcohol Syndrome (FAS) infant facial characteristics on hypothetical adoption preferences, ratings of attractiveness, and ratings of health. As expected, potential parents were more likely to adopt “normal” infants, and they rated the FAS infants as less attractive and less healthy. Cuteness/attractiveness was the best predictor of adoption likelihood.

Infant facial characteristics may affect discriminative parental solicitude because they convey information about the health of the offspring. We examined the effect of Fetal Alcohol Syndrome (FAS) infant facial characteristics on hypothetical adoption preferences, ratings of attractiveness, and ratings of health. As expected, potential parents were more likely to adopt “normal” infants, and they rated the FAS infants as less attractive and less healthy. Cuteness/attractiveness was the best predictor of adoption likelihood.

The principal findings of experimental economics are that impersonal exchange in markets converges in repeated interaction to the equilibrium states implied by economic theory, under information conditions far weaker than specified in the theory. In personal, social, and economic exchange, as studied in two-person games, cooperation exceeds the prediction of traditional game theory. This book relates these two findings to field studies and applications and integrates them with the main themes of the Scottish Enlightenment and with the thoughts of F. (...) A. Hayek. (shrink)

While neo-classical analysis works well for studying impersonal exchange in markets, it fails to explain why people conduct themselves the way they do in their personal relationships with family, neighbors, and friends. In Humanomics, Nobel Prize-winning economist Vernon L. Smith and his long-time co-author Bart J. Wilson bring their study of economics full circle by returning to the founder of modern economics, Adam Smith. Sometime in the last 250 years, economists lost sight of the full range of human feeling, (...) thinking, and knowing in everyday life. Smith and Wilson show how Adam Smith's model of sociality can re-humanize twenty-first century economics by undergirding it with sentiments, fellow feeling, and a sense of propriety - the stuff of which human relationships are built. Integrating insights from The Theory of Moral Sentiments and the Wealth of Nations into contemporary empirical analysis, this book shapes economic betterment as a science of human beings. (shrink)

Professor Vernon L. Smith is a major creator of the new discipline of experimental economics. This collection of his papers from 1962 to 1990 surveys key developments in the field from early attempts to study economic behaviour in now classic double oral auction markets through recent studies of industrial organization and decision making. Topics covered include monopoly and oligopoly, supply and demand theory under posted pricing, uniform pricing, double continuous auction, and sealed bid-offer auctions; hypothetical valuation and market pricing; (...) asset price bubbles; predatory pricing; market contestability and natural monopoly; and the methodology of experimental economics. Taken together, the papers form a history of the study of economics under controlled conditions. (shrink)

This second Cambridge University Press collection of papers by Vernon L. Smith, a creator of the field of experimental economics, includes many of his primary authored and coauthored contributions on bargaining and market behavior between 1990 and 1998. The essays explore the use of laboratory experiments to test propositions derived from economics and game theory. They also investigate the relationship between experimental economics and psychology, particularly the field of evolutionary psychology, using the latter to broaden the perspective in which (...) experimental results are interpreted. The volume complements Professor Smith's earlier work by demonstrating the importance of institutional features of markets in understanding behavior and market performance. Specific themes investigated include rational choice, the notion of fairness, game theory and extensive form experimental interactions, institutions and market behavior, and the study of laboratory stock markets. (shrink)

The rhetoric of hypothesis testing implies that game theory is not testable if a negative result is blamed on any auxiliary hypothesis such as “rewards are inadequate.” This is because either the theory is not falsifiable (since a larger payoff can be imagined, one can always conclude that payoffs were inadequate) or it has no predictive content (the appropriate payoff cannot be prespecified).

Selfishness narrowly defined as choosing dominant outcomes independent of context is widely rejected by experimentalists. Humans live in two worlds of personal and impersonal exchange; both are manifestations of human sociality, but the emphasis on preferences rather than cultural norms of personal exchange across time too much reflects a limited economic modeling, and fails to capitalize on the fresher experimental economics message of culture and diversity.

In light of its history of interpretation, an interpretive essay on the fifth book of Plato's Republic is advanced, on the premise that existing views of the relation of Book V to the rest of the dialogue are inadequate. The metaphor of the "three waves" indicates more than a mere formal unity to the argument of Book V, since the logic of the first two "waves" only becomes evident in light of their dependence upon the logic of the third "wave" (...) . The "three waves" constitute a single, unified argument, which discloses the dependence of justice, as defined in terms of the state and individual in Book IV, upon the idea of the good set forth in Book VI. (shrink)

ABSTRACT Asset‐market bubbles occur dependably in laboratory experiments and almost as reliably throughout economic history—yet they do not usually bring the global economy to its knees. The Crash of 2008 was caused by the bursting of a housing bubble of unusual size that was fed by a massive expansion of mortgage credit—facilitated, in turn, by the longest sustained expansionary monetary policy of the past half century. Much of this mortgage credit was extended to people with little net wealth who made (...) slender down payments, so that when the bubble burst and housing prices declined, their losses quickly exceeded their equity. These losses were transmitted to the financial system—including banks, investment banks, insurance companies, and the institutional and private investors who provided liquidity to the mortgage market through structured securities. It seems that many of these institutions became insolvent; it is certain that they became illiquid. Liquidity loss and solvency fears created a feedback cycle of diminished financing, reduced housing demand, falling housing prices, more borrower losses, and further damage to the financial system and eventually the stock market and the real economy. There are important parallels with the housing and financial‐market booms that led up to the Crash of 1929 and the Great Depression. (shrink)

Tremor of the upper extremity is a significant cause of disability in some patients with multiple sclerosis. The MS tremor is complex because it contains an ataxic intentional tremor component due to the involvement of the cerebellum and cerebellar outflow pathways by MS plaques, which makes the MS tremor, in general, less responsive to medications or deep brain stimulation than those associated with essential tremor or Parkinson's disease. The cerebellar component has been thought to be the main reason for making (...) DBS less effective, although it is not clear whether it is due to the lack of suppression of the ataxic tremor by DBS or else. The goal of this study was to clarify the effect of DBS on cerebellar tremor compared to non-cerebellar tremor in a patient with MS. By wearing an accelerometer on the index finger of each hand, we were able to quantitatively characterize kinetic tremor by frequency and amplitude, with cerebellar ataxia component on one hand and that without cerebellar component on the other hand, at the beginning and end of the hand movement approaching a target at DBS Off and On status. We found that cerebellar tremor surprisingly had as good a response to DBS as the tremor without a cerebellar component, but the function control on cerebellar tremor was not as good due to its distal oscillation, which made the amplitude of tremor increasingly greater as it approached the target. This explains why cerebellar tremor or MS tremor with cerebellar component has a poor functional transformation even with a good percentage of tremor control. This case study provides a better understanding of the effect of DBS on cerebellar tremor and MS tremor by using a wearable device, which could help future studies improve patient selection and outcome prediction for DBS treatment of this disabling tremor. (shrink)

In this study, we used data from the second wave of Midlife in the United States Study, MIDUS Biomarkers and MIDUS 3. We applied the serial mediation model to explore the serial mediating effects of perceived stress and depressive symptoms on the relationship between sleep quality and life satisfaction. A total of 945 participants were included in our study. The total indirect effect of sleep quality on life satisfaction through perceived stress, depressive symptoms and the combination of perceived stress and (...) depressive symptoms accounted for within the overall model was 45.5%. At the intervention level, programs designed to improve the level of life satisfaction among adults should focus on perceived stress and depressive symptoms. The prevention of perceived stress and depression contributes to improving life satisfaction and wellbeing. The serial mediation results should be confirmed by further longitudinal study. (shrink)

We examined disgust and fear responses to spiders in spider-distressed and nondistressed individuals. Undergraduate participants (N = 134) completed questionnaires concerning responses to spiders and other potentially aversive stimuli, as well as measures of disgust sensitivity, anxious arousal, worry, and anhedonic depression. In addition, we obtained self-report and facial expressions of disgust and fear while participants were exposed to a live tarantula. Both spider distressed and nondistressed individuals reported disgust and exhibited disgust facial expressions in response to a tarantula. Disgust (...) in response to spiders was not found to be part of a general disgust response to all negative stimuli, nor was it due to a general negative emotional response to spiders. Emotional responses to spiders were differentially associated with scores on personality and psychological functioning measures. The results of this study provide evidence that spiders have a specific disgust-evoking status in both distressed and nondistressed populations. (shrink)

Taxometric analyses were applied to the construct of psychopathy (as measured by the Psychopathy Checklist) and to several variables reflecting antisocial childhood, adult criminality, and criminal recidivism. Subjects were 653 serious offenders assessed or treated in a maximum-security institution. Results supported the existence of a taxon underlying psychopathy. Childhood problem behaviors provided convergent evidence for the existence of the taxon. Adult criminal history variables were continuously distributed and were insufficient in themselves to detect the taxon.