No postnatal maternal effect on male aggressiveness in wild-derived strains of house mice

Male aggressiveness is a complex behavior influenced by a number of genetic and non-genetic factors. Traditionally, the contribution of each of these factors has been established from experiments using artificially selected strains for high/low aggressive phenotypes. However, little is known about the factors underlying aggressive behavior in natural populations. In this study, we assess the influence of genetic background vs. postnatal maternal environment using a set of cross-fostering experiments between two wild-derived inbred strains, displaying high (STRA, derived from Mus musculus domesticus) and low (BUSNA, derived from Mus musculus musculus) levels of aggressiveness. The role of maternal environment was tested in males with the same genetic background (i.e. strain origin) reared under three different conditions: unfostered (weaned by mother), infostered (weaned by an unfamiliar dam from the same strain), and cross-fostered (weaned by a dam from a different strain). All males were tested against non-aggressive opponents from the A/J inbred strain. Resource-holding potential was assessed through body weight gains and territory ownership. The STRA males were shown to be aggressive in both neutral cage and resident-intruder tests. On the contrary, the BUSNA males were less aggressive in all tests. We did not find a significant effect of postnatal maternal environment; however, we detected significant maternal effect on body weight with differences between the strains, fostering type and interactions between these factors. We conclude that the aggressiveness preserved in the two strains has significant genetic component whose genetic basis can be dissected by quantitative trait loci analysis.     

Uncertainty enhances the preference for narcissistic leaders

Narcissistic leaders present us with an interesting paradox, because they have positive as well as negative characteristics. As such, we argue that the nature of the context determines how suitable narcissists are perceived to be as leaders. Here we propose that a specific contextual factor, that is, uncertainty, increases the preference for narcissists as leaders. As an initial test of this prediction, the first study showed that narcissistic characteristics were evaluated as more desirable in a leader in an uncertain context rather than a certain context. In Studies 2 and 3, we further hypothesized and found that high narcissists are chosen as leaders more often than low narcissists, especially in uncertain (rather than certain) contexts. In all of the studies, individuals were shown to be aware of the negative features of narcissistic leaders, such as arrogance and exploitativeness, but chose them as leaders in times of uncertainty, regardless. Thus, a narcissistic leader is perceived as someone who can help reduce individual uncertainty. These results reveal the importance of contextual uncertainty in understanding the allure of narcissistic leaders. Copyright © 2013 John Wiley & Sons, Ltd.     

Why Choo‐Choo Is Better Than Train: The Role of Register‐Specific Words in Early Vocabulary Growth

Across languages, lexical items specific to infant‐directed speech (i.e., ‘baby‐talk words’) are characterized by a preponderance of onomatopoeia (or highly iconic words), diminutives, and reduplication. These lexical characteristics may help infants discover the referential nature of words, identify word referents, and segment fluent speech into words. If so, the amount of lexical input containing these properties should predict infants’ rate of vocabulary growth. To test this prediction, we tracked the vocabulary size in 47 English‐learning infants from 9 to 21 months and examined whether the patterns of growth can be related to measures of iconicity, diminutives, and reduplication in the lexical input at 9 months. Our analyses showed that both diminutives and reduplication in the input were associated with vocabulary growth, although measures of iconicity were not. These results are consistent with the hypothesis that phonological properties typical of lexical input in infant‐directed speech play a role in early vocabulary growth.     

Reality at odds with perceptions: narcissistic leaders and group performance

Although narcissistic individuals are generally perceived as arrogant and overly dominant, they are particularly skilled at radiating an image of a prototypically effective leader. As a result, they tend to emerge as leaders in group settings. Despite people's positive perceptions of narcissists as leaders, it was previously unknown if and how leaders' narcissism is related to the performance of the people they lead. In this study, we used a hidden-profile paradigm to investigate this question and found evidence for discordance between the positive image of narcissists as leaders and the reality of group performance. We hypothesized and found that although narcissistic leaders are perceived as effective because of their displays of authority, a leader's narcissism actually inhibits information exchange between group members and thereby negatively affects group performance. Our findings thus indicate that perceptions and reality can be at odds and have important practical and theoretical implications.     

The memory of Topoľčany: the relationship of the Jewish inhabitants of Topoľčany after the tragedy of the “Topoľčany pogrom”

The aim of this article is to discuss the town of Topo??any in Slovakia and present the memories and testimonies of the Jewish (and non-Jewish) population about the incident known as “The pogrom of Topo??any.” The topic on which this article will be primarily focused is the relationship and attitude of the former Jewish inhabitants of Topo??any now living far away towards the town after the tragedies that affected it. Moreover, I want to comment on the problematics of “home.” The main questions are how the Jews of Topo??any perceive their birthplace 70 years after the pogrom; how the tragedy has influenced their relationship to Topo??any and its inhabitants; what has changed since then and what has not.     

Internet addiction disorder and chatting in the Czech Republic.

This study analyzes connections between online chatting and the Internet Addiction Disorder (IAD). In the research are compared two groups of respondents--Czech online chat users and Czech university students. The set of answers designed by Kimberly Young, of the University of Pittsburgh, was the common base for research. The research showed that IAD is known among university students, that some of them spend an enormous time on the Internet, and that many of them feel it is a problem. The research also clearly showed that the most serious chat users more often have problems with IAD than other university students.     

Triadic awareness predicts partner choice in male–infant–male interactions in Barbary macaques

Social knowledge beyond one’s direct relationships is a key in successfully manoeuvring the social world. Individuals gather information on the quality of social relationships between their group companions, which has been termed triadic awareness. Evidence of the use of triadic awareness in natural contexts is limited mainly to conflict management. Here we investigated triadic awareness in wild Barbary macaques (Macaca sylvanus) in the context of bridging interactions defined as male–infant–male interactions whereby a male (initiator, holder) presents an infant to another male (receiver, non-holder) in order to initiate an affiliative interaction with that male. Analyses based on 1263 h of focal observations on ten infants of one wild social group in Morocco supported the hypothesis that males use their knowledge of the relationship between infants and other adult males when choosing a male as a partner for bridging interactions. Specifically, (i) the number of bridging interactions among holder–infant–receiver triads was positively affected by the strength of the infant–receiver relationship and (ii) when two males were available as bridging partners, a male was more likely to be chosen as the receiver the stronger his social relationship with the infant relative to the other available male. This demonstrates that non-human primates establish triadic awareness of temporary infant–male relationships and use it in a naturally occurring affiliative context. Our results contribute to the discussion about the mechanism underlying the acquisition of triadic awareness and the benefits of its usage, and lend support to hypotheses linking social complexity to the evolution of complex cognition.     

Estimation of the probability of fighting in fallow deer (Dama dama) during the rut

Fighting between males is a frequent component of the rutting behavior of Cervidae. Frequent conflicts are exhausting; fighting may be risky and can lead to serious injuries or even death. We focused on the process of assessment of the opponent's fighting ability and escalation of the combat, estimating the probability of fighting based on the encounter components such as groaning and parallel walk. In this study, we observed the agonistic behavior of fallow deer bucks (Dama dama) during the rut over four seasons. During this time, we recorded 205 encounters between bucks. Non-contact display, which allows contestants to assess their opponents fighting ability, occurred in 83% of the encounters. The highest predicted probability of a fight was found when both of the males vocalized and turned into the parallel walk. The chance of a clear outcome decreased when the males were fighting in comparison to when they did not fight. The initiator of the competitive encounter won 41% of the cases, while the attacked buck won 23% of the encounters. If the contestants avoided fighting, however, the initiator won 78% of encounters. Therefore, the initiator was more successful when no fight occurred compared to when the encounters escalated into fighting. In most cases where ritualized behavior occurred, one of the opponents left after vocalization or parallel walk occurred. Thus, vocalization and parallel walk increased the probability for a clear outcome. The probability of a fight was lowest in situations where the males displayed asymmetric behavior. Increased symmetry of the contestants' behavior was strongly correlated with a higher probability of a fight. Thus, these results indicate that fallow deer bucks use efficient tactic during the rut, which, in turn, minimizes the chance of injury while fighting during the breeding season.     

The Bright Side of Threatened Narcissism: Improved Performance Following Ego Threat

Narcissistic individuals have highly positive self‐views and overestimate their abilities. Consequently, they tend to react aggressively whenever they receive information that does not match their high self‐views (ego threat). We argue that focusing on aggression merely portrays a one‐sided view of narcissistic individuals and the manner in which they counter ego threats. We propose that following ego threat, narcissism can also fuel performance. In four studies, we measured nonclinical narcissism and allocated Dutch undergraduate university students (N₁ = 175, N₂ = 142, N₃ = 159, N₄ = 174) to either an ego threat or a no ego threat condition. Ego threat involved negative feedback (Studies 1–2) or threat to uniqueness (Studies 3–4). We measured participants’ intentions to complete a challenging task (Study 1), their creative performance (Studies 2–3), and their performance on an anagram task (Study 4). Across Studies 1–3, we consistently found that following ego threat, higher nonclinical narcissism was associated with greater willingness to perform tasks that enabled demonstration of abilities and enhanced creative performance. These results were confirmed using a meta‐analysis. However, anagram performance was not enhanced following ego threat. We provide additional analyses that might help explain this. Our findings thus reveal a more positive side to the way narcissistic individuals manage threats to their self‐image.