When can we say 'if'?

In this study, we focus on the conditions which permit people to assert a conditional statement of the form 'if p then q' with conversational relevance. In a broadly decision-theoretic approach, also drawing on hypothetical thinking theory [Evans, J. St. B. T. (2007). Hypothetical thinking: Dual processes in reasoning and judgement. Hove, UK: Psychology Press.], we predicted that conditional tips and promises would appear more useful and persuasive and be more likely to encourage an action p when (a) the conditional link from p to q was stronger, (b) the cost of the action p was lower and (c) the benefit of the consequence q was higher. Similarly, we predicted that conditional warnings and threats would be seen as more useful and persuasive and more likely to discourage an action p when (a) the conditional link from p to q was stronger, (b) the benefit of the action p was lower and (c) the cost of the consequence q was higher. All predictions were strongly confirmed, suggesting that such conditionals may best be asserted when they are of high relevance to the goals of the listener.     

Behavioral correlates of selected MMPI-2 clinical, content, and restructured clinical scales

In this study, we evaluated the validity of the Restructured Clinical (RC; Tellegen et al., 2003) scales by identifying and comparing behavioral correlates of selected RC scales (RCd, RC2, RC4), their original Clinical scale counterparts (Scale 2, Scale 4), and conceptually related Content scales (DEP, ASP, CYN) in an outpatient clinical sample (N = 150). The results of this study indicate that RC4 is a stronger predictor of several antisocial behaviors than Clinical Scale 4 or the Content Scales ASP and CYN. In contrast, RC2 demonstrated significantly lower correlations with several behaviors conceptually related to depression than its Clinical scale counterpart or DEP. DEP was highly correlated with RCd (r = .91, p < .0001), suggesting that the 2 scales may be measuring similar constructs. Overall, the results of this study demonstrate relatively few differences among the scales selected in their ability to predict extratest behaviors.     

Sensitivity to triadic attention between 6 weeks and 3 months of age

In Study 1, 6-week- and 3-month-old infants gazed more to an adult when she alternated attention between an object and the infant versus when attention was directed only to the object. In Study 2, 6-week-olds did not discriminate between triadic situations with face-to-face interaction controlled.     

Cumulative risk, maternal responsiveness, and allostatic load among young adolescents

The purpose of this study was to examine the impact of cumulative risk exposure in concert with maternal responsiveness on physiological indicators of chronic stress in children and youth. Middle-school children exposed to greater accumulated psychosocial (e.g., family turmoil, poverty) and physical (e.g., crowding, substandard housing) risk factors manifested higher levels of allostatic load, a physiological marker of cumulative wear and tear on the body caused by the mobilization of multiple, physiological response systems. This effect was longitudinal, residualizing allostatic load 3-4 years earlier when the youth were in elementary school. This effect, however, occurred only among adolescents with mothers low in responsiveness. Cumulative risk was also associated with dynamic cardiovascular processes in response to an acute stressor (mental arithmetic). Higher risk was associated with muted reactivity and slower, less efficient recovery in blood pressure. These dynamic cardiovascular effects occurred irrespective of maternal responsiveness.     

The probability of causal conditionals

Conditionals in natural language are central to reasoning and decision making. A theoretical proposal called the Ramsey test implies the conditional probability hypothesis: that the subjective probability of a natural language conditional, P(if p then q), is the conditional subjective probability, P(q/p). We report three experiments on causal indicative conditionals and related counterfactuals that support this hypothesis. We measured the probabilities people assigned to truth table cases, P(pq), P(p notq), P( notpq) and P( notp notq). From these ratings, we computed three independent predictors, P(p), P(q/p) and P(q/ notp), that we then entered into a regression equation with judged P(if p then q) as the dependent variable. In line with the conditional probability hypothesis, P(q/p) was by far the strongest predictor in our experiments. This result is inconsistent with the claim that causal conditionals are the material conditionals of elementary logic. Instead, it supports the Ramsey test hypothesis, implying that common processes underlie the use of conditionals in reasoning and judgments of conditional probability in decision making.     

Quantity judgments of sequentially presented food items by capuchin monkeys (Cebus apella)

Recent assessments have shown that capuchin monkeys, like chimpanzees and other Old World primate species, are sensitive to quantitative differences between sets of visible stimuli. In the present study, we examined capuchins’ performance in a more sophisticated quantity judgment task that required the ability to form representations of food quantities while viewing the quantities only one piece at a time. In three experiments, we presented monkeys with the choice between two sets of discrete homogeneous food items and allowed the monkeys to consume the set of their choice. In Experiments 1 and 2, monkeys compared an entirely visible food set to a second set, presented item-by-item into an opaque container. All monkeys exhibited high accuracy in choosing the larger set, even when the entirely visible set was presented last, preventing the use of one-to-one item correspondence to compare quantities. In Experiment 3, monkeys compared two sets that were each presented item-by-item into opaque containers, but at different rates to control for temporal cues. Some monkeys performed well in this experiment, though others exhibited near-chance performance, suggesting that this species’ ability to form representations of food quantities may be limited compared to previously tested species such as chimpanzees. Overall, these findings support the analog magnitude model of quantity representation as an explanation for capuchin monkeys’ quantification of sequentially presented food items.

Seeking an ethical and legal way of procuring transplantable organs from the dying without further attempts to redefine human death

Because complex organs taken from unequivocally dead people are not suitable for transplantation, human death has been redefined so that it can be certified at some earlier stage in the dying process and thereby make viable organs available without legal problems. Redefinitions based on concepts of "brain death" have underpinned transplant practice for many years although those concepts have never found universal philosophical acceptance. Neither is there consensus about the clinical tests which have been held sufficient to diagnose the irreversible cessation of all brain function – or as much of it as is deemed relevant – while the body remains alive.     

Parents as moderators of psychological and physiological correlates of inner-city children's exposure to violence

This paper discusses the psychological and physiological correlates of inner-city violence on children, and the potential mediating and moderating roles of parents. Data are based on interviews regarding exposure to community violence (ECV), parenting practices, child distress, posttraumatic symptomology, and competence. Cardiovascular activation was also measured. Community violence exposure related to distress, posttraumatic symptomology, and incompetence. Harsh parenting related to aggression, distress, incompetence, and higher heart rates. Parenting moderated but did not mediate the effects of violence on measures of competence. High violence plus harsh parenting predicted lower levels of systolic (SBP) and diastolic blood pressure (DBP). Results are discussed within an ecological framework of parent–child relations and as they relate to the conclusion that children undergoing dual levels of stress may experience a dissociative response.     

Necessity, possibility and belief: A study of syllogistic reasoning

The present study extended the investigation of the belief bias effect in syllogistic reasoning in two ways: (1) The effect was studied under instructions to decide whether conclusions were possible, as well as necessary, given the premises; and (2) the effect was studied for types of syllogism where people rarely endorse the conclusions as well as those (valid and fallacious) where endorsements are common. Three experiments are reported, which show first that there is a marked tendency to reject unbelievable conclusions relative to abstract or neutral controls on all kinds of syllogism and under both types of instruction. There was also significant evidence of positive belief bias (increased acceptance of believable conclusions) and of interactions between belief bias effects and logical form. The results are discussed with particular respect to accounts of belief bias offered by theorists in the mental-model tradition.