Capturing hearts and minds: The influence of relational identification with the leader on followers' mobilization and cardiovascular reactivity

The influence of relational identification (RI) on leadership processes and the effects of social identity leadership on followers' responses to stress have received scant theoretical and research attention. The present research advances theoretical understanding by testing the assertion that high RI with the leader drives follower mobilization of effort and psychophysiological responses to stress. Two experimental scenario studies (Study 1 and Study 2) support the hypothesis that being led by an individual with whom followers perceive high RI increases follower intentional mobilization. Study 2 additionally showed that high (vs. low) RI increases follower resource appraisals and cognitive task performance. A laboratory experiment (Study 3) assessing cardiovascular (CV) reactivity showed that, compared to neutral (i.e., non-affiliated) leadership, being led by an individual with whom participants felt low RI elicited a maladaptive (i.e., threat) response to a pressurized task. In addition, relative to the low RI and neutral conditions, high RI with the leader did not engender greater challenge or threat reactivity. In conclusion, advancing social identity leadership and challenge and threat theory, findings suggest that leaders should be mindful of the deleterious effects (i.e., reduced mobilization and greater threat state) of low RI to optimize follower mobilization of effort and psychophysiological responses to stress.     

On tree representations of relations and graphs: symbolic ultrametrics and cograph edge decompositions

Tree representations of (sets of) symmetric binary relations, or equivalently edge-colored undirected graphs, are of central interest, e.g. in phylogenomics. In this context symbolic ultrametrics play a crucial role. Symbolic ultrametrics define an edge-colored complete graph that allows to represent the topology of this graph as a vertex-colored tree. Here, we are interested in the structure and the complexity of certain combinatorial problems resulting from considerations based on symbolic ultrametrics, and on algorithms to solve them.This includes, the characterization of symbolic ultrametrics that additionally distinguishes between edges and non-edges of arbitrary edge-colored graphs G and thus, yielding a tree representation of G, by means of so-called cographs. Moreover, we address the problem of finding “closest” symbolic ultrametrics and show the NP-completeness of the three problems: symbolic ultrametric editing, completion and deletion. Finally, as not all graphs are cographs, and hence, do not have a tree representation, we ask, furthermore, what is the minimum number of cotrees needed to represent the topology of an arbitrary non-cograph G. This is equivalent to find an optimal cograph edge k-decomposition \(\{E_1,\dots ,E_k\}\) of E so that each subgraph \((V,E_i)\) of G is a cograph. We investigate this problem in full detail, resulting in several new open problems, and NP-hardness results.For all optimization problems proven to be NP-hard we will provide integer linear program formulations to solve them.     

Konformit?t durch Herdenverhalten

The adjustment of one??s own actions to the behavior of others offers an inexpensive alternative to self-reliant reasoning. Thus, from a sociological perspective conformity mirrors informative social influences. First, a basic model of social herding is presented, which describes initial conditions and consequences of informational imitation. Central implications of the model are then tested using process-produced data from the German book market (2001?C2006). While the release of public information as well as announcements by opinion leaders trigger conformity under imperfect information, these stimuli show no effects when the general availability of information is improved. Moreover, the availability of information among readers determines the quality of emerging bestsellers. Altogether, the model of herd behavior proves useful in understanding demand processes in book markets.     

Sex on the brain?: an examination of frequency of sexual cognitions as a function of gender, erotophilia, and social desirability

It is commonly believed that men think about sex much more often than do women, but the empirical evidence in this area is fairly weak. By means of a golf tally counter, 283 college students kept track of their thoughts pertaining to food, sleep, or sex for one week. Males reported significantly more need-based cognitions overall, but there was no significant interaction between sex of participant and type of cognition recorded. Therefore, although these young men did think more about sex than did young women, they also thought more about food and sleep. In contrast, a retrospective estimated frequency of need-based cognitions obtained at the start of the study revealed a sex difference in sexual cognitions, but not thoughts about eating or sleeping. Erotophilia and sexual desirability responding were significant predictors of frequency of sexual cognitions for women, but not for men. Overall, erotophilia was a better predictor of sexual cognition than was sex of participant. Taken as a whole, the results suggest that, although there may be a sex difference in sexual cognitions, it is smaller than is generally thought, and the reporting is likely influenced by sex role expectations.     

The undercut procedure: an algorithm for the envy-free division of indivisible items

We propose a procedure for dividing a set of indivisible items between two players. We assume that each player’s preference over subsets of items is consistent with a strict ranking of the items, and that neither player has information about the other’s preferences. Our procedure ensures an envy-free division—each player receives a subset of items that it values more than the other player’s complementary subset—given that an envy-free division of “contested items,” which the players would choose at the same time, is possible. We show that the possibility of one player’s undercutting the other’s proposal, and implementing the reduced subset for himself or herself, makes the proposer “reasonable,” and generally leads to an envy-free division, even when the players rank items exactly the same. Although the undercut procedure is manipulable and its envy-free allocation may be Pareto-inferior, each player’s maximin strategy is to be truthful. Applications of the procedure are discussed briefly.     

What college students do not know: where are the gaps in sexual health knowledge?

Abstract Objective: This study aimed to understand the gaps in college students' knowledge regarding sexual health information. Participants: A sample of 242 participants enrolled in an introductory college course participated in this study in the Fall 2009 semester. Methods: Students participated in 1 of 2 brief interventions and wrote a response paper about their experience. The papers were analyzed using conventional content analysis for information that was new to participants by looking for key words that suggested learning took place. Results: The findings indicated that the majority of participants learned new information. Most learning occurred regarding sexually transmitted infections (ie, types, symptoms, prevalence, treatment, testing) and correct condom use. There were also demographic differences regarding reported new information. Conclusions: Findings can be used to develop future sex education programs for college students by providing college educators with an understanding of where students lack knowledge of sexual health.     

Links between childhood physical abuse and intimate partner aggression: the mediating role of anger expression

Research linking childhood physical abuse (CPA) and adult intimate partner aggression (IPA) has focused on individuals without sufficient attention to couple processes. In this study, 109 couples reported on histories of CPA, IPA, and anger expression. Actor-partner interdependence model (APIM) was used to examine links between CPA and revictimization and perpetration of IPA, with anger suppression as a potential mediator. Women's CPA histories were associated with more physical aggression towards and more revictimization by partners. Men's CPA histories were only associated at the trend level with their revictimization. Anger suppression fully mediated the link between women's CPA and both revictimization and perpetration of IPA. Findings suggest that women with CPA histories are more prone to suppress anger, which leaves them at greater risk for revictimization and perpetration of IPA.     

An Overview of and Rationale for Changes Proposed for Pathological Gambling in DSM-5

The fifth revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) is scheduled for publication in 2013. It will include several changes to the diagnosis of pathological gambling: the name of the disorder will be altered, the threshold for diagnosis will decrease, and one criterion will be removed. This paper reviews the rationale for these changes and addresses how they may impact diagnosis and treatment of the disorder, as well as potential for future research in the field.     

Movement-in-depth, cognitive impairment, and crash risk

In this study, 243 cognitively intact and cognitively impaired older participants' movement-in-depth (looming) abilities were assessed using a portable device that we had previously developed in our laboratory. Results indicated normative relationships between looming ability and age, looming ability and driving violation records, and age and driving violation records. Findings also confirmed the validity and reliability of the measurements taken with the device. In conclusion, this device may be useful for identifying drivers at risk for rear-end collisions, developing effective training interventions, and creating fair and valid driver licensing tests.