Knowledge that Transforms

Previous research has shown that children benefit from gesturing during math instruction. We asked whether gesturing promotes learning because it is itself a physical action, or because it uses physical action to represent abstract ideas. To address this question, we taught third-grade children a strategy for solving mathematical-equivalence problems that was instantiated in one of three ways: (a) in a physical action children performed on objects, (b) in a concrete gesture miming that action, or (c) in an abstract gesture. All three types of hand movements helped children learn how to solve the problems on which they were trained. However, only gesture led to success on problems that required generalizing the knowledge gained. The results provide the first evidence that gesture promotes transfer of knowledge better than direct action on objects and suggest that the beneficial effects gesture has on learning may reside in the features that differentiate it from action.

Psychological research using mostly cross-sectional methods calls into question the presumed function of shame as an inhibitor of immoral or illegal behavior. In a longitudinal study of 476 jail inmates, we assessed shame proneness, guilt proneness, and externalization of blame shortly after incarceration. We interviewed participants (N = 332) 1 year after release into the community, and we accessed official arrest records (N = 446). Guilt proneness negatively and directly predicted reoffense in the 1st year after release; shame proneness did not. Further mediational modeling showed that shame proneness positively predicted recidivism via its robust link to externalization of blame. There remained a direct effect of shame on recidivism: Unimpeded by defensive externalization of blame, shame inhibited recidivism. Items assessing a motivation to hide were primarily responsible for this pattern. Overall, our results suggest that the pain of shame may have two faces-one with destructive potential and the other with constructive potential.

This research reported here speaks to a contentious debate concerning the potential negative consequences of diversity for trust. We tested the relationship between neighborhood diversity and out-group, in-group, and neighborhood trust, taking into consideration previously untested indirect effects via intergroup contact and perceived intergroup threat. A large-scale national survey in England sampled White British majority (N = 868) and ethnic minority (N = 798) respondents from neighborhoods of varying degrees of diversity. Multilevel path analyses showed some negative direct effects of diversity for the majority group but also confirmed predictions that diversity was associated indirectly with increased trust via positive contact and lower threat. These indirect effects had positive implications for total effects of diversity, cancelling out most negative direct effects. Our findings have relevance for a growing body of research seeking to disentangle effects of diversity on trust that has so far largely ignored the key role of intergroup contact.

Economic inequality in America is at historically high levels. Although most Americans indicate that they would prefer greater equality, redistributive policies aimed at reducing inequality are frequently unpopular. Traditional accounts posit that attitudes toward redistribution are driven by economic self-interest or ideological principles. From a social psychological perspective, however, we expected that subjective comparisons with other people may be a more relevant basis for self-interest than is material wealth. We hypothesized that participants would support redistribution more when they felt low than when they felt high in subjective status, even when actual resources and self-interest were held constant. Moreover, we predicted that people would legitimize these shifts in policy attitudes by appealing selectively to ideological principles concerning fairness. In four studies, we found correlational (Study 1) and experimental (Studies 2-4) evidence that subjective status motivates shifts in support for redistributive policies along with the ideological principles that justify them.

The relative importance of nature and nurture for various forms of expertise has been intensely debated. Music proficiency is viewed as a general model for expertise, and associations between deliberate practice and music proficiency have been interpreted as supporting the prevailing idea that long-term deliberate practice inevitably results in increased music ability. Here, we examined the associations (rs = .18-.36) between music practice and music ability (rhythm, melody, and pitch discrimination) in 10,500 Swedish twins. We found that music practice was substantially heritable (40%-70%). Associations between music practice and music ability were predominantly genetic, and, contrary to the causal hypothesis, nonshared environmental influences did not contribute. There was no difference in ability within monozygotic twin pairs differing in their amount of practice, so that when genetic predisposition was controlled for, more practice was no longer associated with better music skills. These findings suggest that music practice may not causally influence music ability and that genetic variation among individuals affects both ability and inclination to practice.

Caregiving touch has been shown to be essential for the growth and development of human infants. However, the physiological and behavioral mechanisms that underpin infants' sensitivity to pleasant touch are still poorly understood. In human adults, a subclass of unmyelinated peripheral nerve fibers has been shown to respond preferentially to medium-velocity soft brushing. It has been theorized that this privileged pathway for pleasant touch is used for close affiliative interactions with conspecific individuals, especially between caregivers and infants. To test whether human infants are sensitive to pleasant touch, we examined arousal (heart rate) and attentional engagement (gaze shifts and duration of looks) to varying velocities of brushing (slow, medium, and fast) in 9-month-old infants. Our results provide physiological and behavioral evidence that sensitivity to pleasant touch emerges early in development and therefore plays an important role in regulating human social interactions.

Are people wiser when reflecting on other people's problems compared with their own? If so, does self-distancing eliminate this asymmetry in wise reasoning? In three experiments (N = 693), participants displayed wiser reasoning (i.e., recognizing the limits of their knowledge and the importance of compromise and future change, considering other people's perspectives) about another person's problems compared with their own. Across Studies 2 and 3, instructing individuals to self-distance (rather than self-immerse) eliminated this asymmetry. Study 3 demonstrated that each of these effects was comparable for younger (20-40 years) and older (60-80 years) adults. Thus, contrary to the adage "with age comes wisdom," our findings suggest that there are no age differences in wise reasoning about personal conflicts, and that the effects of self-distancing generalize across age cohorts. These findings highlight the role that self-distancing plays in allowing people to overcome a pervasive asymmetry that characterizes wise reasoning.

Even though painful experiences are employed within social rituals across the world, little is known about the social effects of pain. We examined the possibility that painful experiences can promote cooperation within social groups. In Experiments 1 and 2, we induced pain by asking some participants to insert their hands in ice water and to perform leg squats. In Experiment 3, we induced pain by asking some participants to eat a hot chili pepper. Participants performed these tasks in small groups. We found evidence for a causal link: Sharing painful experiences with other people, compared with a no-pain control treatment, promoted trusting interpersonal relationships by increasing perceived bonding among strangers (Experiment 1) and increased cooperation in an economic game (Experiments 2 and 3). Our findings shed light on the social effects of pain, demonstrating that shared pain may be an important trigger for group formation.

A large body of evidence supports the importance of focused attention for encoding and task performance. Yet young children with immature regulation of focused attention are often placed in elementary-school classrooms containing many displays that are not relevant to ongoing instruction. We investigated whether such displays can affect children's ability to maintain focused attention during instruction and to learn the lesson content. We placed kindergarten children in a laboratory classroom for six introductory science lessons, and we experimentally manipulated the visual environment in the classroom. Children were more distracted by the visual environment, spent more time off task, and demonstrated smaller learning gains when the walls were highly decorated than when the decorations were removed.

Five university-based research groups competed to recruit forecasters, elicit their predictions, and aggregate those predictions to assign the most accurate probabilities to events in a 2-year geopolitical forecasting tournament. Our group tested and found support for three psychological drivers of accuracy: training, teaming, and tracking. Probability training corrected cognitive biases, encouraged forecasters to use reference classes, and provided forecasters with heuristics, such as averaging when multiple estimates were available. Teaming allowed forecasters to share information and discuss the rationales behind their beliefs. Tracking placed the highest performers (top 2% from Year 1) in elite teams that worked together. Results showed that probability training, team collaboration, and tracking improved both calibration and resolution. Forecasting is often viewed as a statistical problem, but forecasts can be improved with behavioral interventions. Training, teaming, and tracking are psychological interventions that dramatically increased the accuracy of forecasts. Statistical algorithms (reported elsewhere) improved the accuracy of the aggregation. Putting both statistics and psychology to work produced the best forecasts 2 years in a row.