Tactile perception of thermal diffusivity

The thermal diffusivity of an object is a parameter that controls the rate at which heat is extracted from the hand when it touches that object. It is an important feature for distinguishing materials by means of touch. In order to quantitatively describe the ability of human observers to discriminate between materials on the basis of heat extraction rate, we conducted an experiment in which this heat extraction was performed in a controlled way. In different conditions, subjects were repeatedly asked to select from two stimuli the one that cooled faster. The discrimination threshold was around 43% of the extraction rate. A rate that was twice as slow also yielded twice the absolute threshold. When we halved the temperature difference between the beginning and end of the stimulus, the threshold did not change as much. In separate experiments, we investigated the different cues that were available in the stimulus: initial cooling rate and end temperature. Both cues were used for discrimination, but cooling rate seemed to be the most important.     

Accountability and dignity: Ethical issues in forensic and correctional practice

Our aim in the special issue is to address some of the more abstract and fundamental ethical problems evident in the criminal justice system and to inquire into their significance for those individuals who assess and deliver rehabilitation programs to offenders. In order to provide an appropriate theoretical framework for an investigation of ethical concerns in the forensic and correctional practice domains, we first outline an ethical framework that is intended to help practitioners reflect systematically on their practice [Ward, T., & Syversen, K., (2009). Vulnerable agency and human dignity: An ethical framework for forensic practice. Aggression and Violent Behavior, 14, 94–105]. Second, we explicitly examine the relationship between two normative frameworks evident within the criminal justice system, punishment and rehabilitation, and inquire into their relationship. Finally, we briefly describe each of the papers comprising the special issue.     

Dominance or prestige: A review of the effects of power poses and other body postures

Research on the effects of body positions has attracted enormous attention in recent years but has been plagued by failed replication attempts. Today, there is some confusion about which effects can be considered reliable. One problem that may have contributed to this confusion is the fact that most previous studies have not clearly distinguished between different types of body positions. We apply the dominance‐prestige framework to distinguish between two types of body positions. On the basis of this reasoning, we argue that research on so‐called power poses in fact has analyzed expansiveness as an indicator of dominance, whereas research on postures has focused on the straightness of the spine, which may be seen as a display of prestige. We review the literature and conclude that there is no clear evidence that short‐term interventions involving body positions affect physiology or behavior. Still, there are effects on actors' self‐perceptions. Repeatedly, studies on power poses have found effects on feelings of power and self‐evaluations, and studies on postures have found effects on emotional experience. However, there is hardly any research that has directly compared the two types of interventions.     

Prosocial tendencies predict friendship quality, but not for popular children

Is prosocial behavior a prerequisite for having good-quality friendships? This study (N = 477, mean age = 12.2 years) examined whether the link between children’s prosocial tendencies and their perceived friendship quality was dependent on children’s level of popularity in the peer group. Children’s prosocial tendencies were assessed both as observed behavior in a standardized setting and as a self-reported predisposition to act in prosocial ways. Across measures, the results showed that prosocial tendencies are associated with higher perceived friendship quality among nonpopular children (i.e., children holding average or lower levels of popularity), but not among popular children. Thus, even if they lack prosocial qualities, popular children are still able to hold good-quality friendships. Popular children may have other compensating characteristics, such as popularity by association, that make them attractive for peers to be friends with.     

Tainted visions: the effect of visionary leader behaviors and leader categorization tendencies on the financial performance of ethnically diverse teams

Despite the increasing prevalence of ethnic diversity, findings regarding its effects on team performance remain contradictory. We suggest that past inconsistencies can be reconciled by examining the joint impact of leader behavior and leader categorization tendencies in ethnically diverse teams. We propose that leaders who exhibit high levels of visionary leader behavior and also have the tendency to categorize their team members into in- and out-groups will facilitate a negative effect of ethnic diversity on team communication and financial performance, whereas leaders who exhibit visionary behaviors but do not tend to categorize will lead ethnically diverse teams to positive outcomes. We find support for these ideas in a study of 100 retail outlets.     

Valence-specific laterality effects in vocal emotion: interactions with stimulus type, blocking and sex

Valence-specific laterality effects have been frequently obtained in facial emotion perception but not in vocal emotion perception. We report a dichotic listening study further examining whether valence-specific laterality effects generalise to vocal emotions. Based on previous literature, we tested whether valence-specific laterality effects were dependent on blocked presentation of the emotion conditions, on the naturalness of the emotional stimuli, or on listener sex. We presented happy and sad sentences, paired with neutral counterparts, dichotically in an emotion localisation task, with vocal stimuli being preceded by verbal labels indicating target emotions. The measure was accuracy. When stimuli of the same emotion were presented as a block, a valence-specific laterality effect was demonstrated, but only in original stimuli and not morphed stimuli. There was a separate interaction with listener sex. We interpret our findings as suggesting that the valence-specific laterality hypothesis is supported only in certain circumstances. We discuss modulating factors, and we consider whether the mechanisms underlying those factors may be attentional or experiential in nature.     

Preferring the One in the Middle: Further Evidence for the Centre‐stage Effect

The location of an item influences a person's preference for that item, but it is unclear whether there is a preference for items located on the right or in the centre. In replication of the centre‐stage effect, it was found that when participants were presented with a line of five pictures, they preferred pictures in the centre rather than at either end. This applies when the line of pictures was arranged horizontally or vertically and when participants selected from five pairs of identical socks arranged vertically. The results support the centre‐stage explanation of location‐based preference rather than the hemispheric difference or body‐specific accounts. Implications of the effects of location on consumer choices and preference decisions are discussed. Copyright © 2011 John Wiley & Sons, Ltd.     

Salient material properties and haptic volume perception: The influences of surface texture, thermal conductivity, and compliance

We investigated the influences of surface texture, thermal conductivity, and compliance on the haptic perception of the volume of small cubes. It was hypothesized that an object containing highly salient material properties would be perceived as larger in volume than the same object without these properties. Blindfolded subjects were asked to explore pairs of cubes differing in their material properties and to select the one with the larger volume. The results showed that, counterintuitively, a smooth cube was perceived as being significantly larger than a rough cube of the same physical volume, with average biases of about 19 %. Furthermore, cubes with a higher thermal conductivity were perceived as significantly larger than cubes with a lower thermal conductivity (average bias of about 7 %). In addition, the magnitude of the bias in this condition was not changed by increasing or decreasing the temperature of the test objects, suggesting that the effect of thermal conductivity could not be attributed directly to the heat flow. Finally, a hard cube was perceived as significantly larger than a soft cube of equal physical volume, with an average bias of about 25 %. These results reveal that the studied material properties have significant and consistent influences on the haptic perception of volume. The observed biases provide an indication of the levels at which the processing of haptic information on volume and material properties occurs.     

Preference for Violent Electronic Games and Aggressive Behavior among Children: The Beginning of the Downward Spiral?

A one-year longitudinal study with 324 German third and fourth graders was conducted in order to find out whether a preference for violent electronic games socializes children to become more aggressive or whether aggressive individuals tend to select this type of game. Cross-lagged panel analyses suggest that children who were rated as openly aggressive at Time 1 intensified their preference for violent electronic games over time. We determined that it could be ruled out that this selection effect was due to a number of underlying variables ranging from ecological variables (neighborhood) to family variables (migration status, older brother) and child variables (gender, self-esteem, level of achievement). Discussion focuses on the emerging preference for violent electronic games among children.     

The use of exploratory procedures by blind and sighted adults and children

The study examined exploratory procedures (EPs) of congenitally blind and sighted children and adults on a haptic match-to-sample task. The aim was to examine the influence of age, visual status, and familiarity on the use of EPs when people haptically examine the object properties of weight, size, exact shape, and texture. EPs in the first and last of four series of trials were compared. The results showed that all four groups chose the same dominant EP for examining the four different object properties, all of them in agreement with the ones found by Lederman and Klatzky (Cognitive Psychology 19:342–368, 1987). Children were found to use more EPs, rather than using only the most efficient EP, for the dimension under study. Overall, performance was affected more by age than by visual status, and repeating the task led to increased efficiency in all groups. To describe exploratory behaviors in more detail, actions were introduced. Actions are single or sequential hand movements occurring in parallel with the EPs or apart from the EPs. The use of actions explained, in part, individual variation among the participants.