No abstract

Similar to the nonverbal signals shown by many nonhuman animals during aggressive conflicts, humans display a broad range of behavioral signals to advertise and augment their apparent size, strength, and fighting prowess when competing for social dominance. Favored by natural selection, these signals communicate the displayer's capacity and willingness to inflict harm, and increase responders' likelihood of detecting and establishing a rank asymmetry, and thus avoiding costly physical conflicts. Included among this suite of adaptations are vocal changes, which occur in a wide range of nonhuman animals (e.g., chimpanzees, rhesus monkeys) prior to aggression, but have not been systematically examined in humans. The present research tests whether and how humans use vocal pitch modulations to communicate information about their intention to dominate or submit. Results from Study 1 demonstrate that in the context of face-to-face group interactions, individuals spontaneously alter their vocal pitch in a manner consistent with rank signaling. Raising one's pitch early in the course of an interaction predicted lower emergent rank, whereas deepening one's pitch predicted higher emergent rank. Results from Study 2 provide causal evidence that these vocal shifts influence perceptions of rank and formidability. Together, findings suggest that humans use transient vocal changes to track, signal, and coordinate status relationships.

Protonated 1,4-benzodiazepines dissociate in the gas phase by the common pathway of CO elimination and by unique pathways dictated by the substituents; the latter typically differentiate one benzodiazepine from another. Protonated 3-dihydro-5-phenyl-1,4-benzodiazepin-2-one, the base diazepam devoid of substituents, dissociates by eliminating CO, HNCO, benzene, and benzonitrile. Mechanisms of these reactions are proposed with ionic products being resonance stabilized. The abundant [MH-CO]+ ion dissociates to secondary products via elimination of benzene, benzonitrile, the NH2 radical, and ammonia, yielding again ionic products that are stabilized by resonance.

We propose and test the overconfidence transmission hypothesis, which predicts that individuals calibrate their self-assessments in response to the confidence others display in their social group. Six studies that use a mix of correlational and experimental methods support this hypothesis. Evidence indicates that individuals randomly assigned to collaborate in laboratory dyads converged on levels of overconfidence about their own performance rankings. In a controlled experimental context, observing overconfident peers causally increased an individual's degree of bias. The transmission effect persisted over time and across task domains, elevating overconfidence even days after initial exposure. In addition, overconfidence spread across indirect social ties (person to person to person), and transmission operated "stealthily," outside of reported awareness. However, individuals showed a selective in-group bias; overconfidence was acquired only when cued by a member of one's in-group (and not out-group), consistent with theoretical notions of selective learning bias. Combined, these results advance understanding of the social factors that underlie inter-individual differences in overconfidence, and suggest that social transmission processes may be in part responsible for why local "confidence traditions" emerge in groups, teams, and organizations.

Dominant leadership is, surprisingly, on the rise globally. Previous studies have found that intergroup conflict increases followers’ support for dominant leaders, but identifying the potential benefits that such leaders can supply is crucial to explaining their rise. We took a behavioral-economics approach in Study 1 ( N = 288 adults), finding that cooperation among followers increases under leaders with a dominant reputation. This pattern held regardless of whether dominant leaders were assigned to groups, elected through a bidding process, or leading under intergroup competition. Moreover, Studies 2a to 2e ( N = 1,022 adults) show that impressions of leader dominance evoked by personality profiles, authoritarian attitudes, or physical formidability similarly increase follower cooperation. We found a weaker but nonsignificant trend when dominance was cued by facial masculinity and no evidence when dominance was cued by aggressive disposition in a decision game. These findings highlight the unexpected benefits that dominant leaders can bestow on group cooperation through threat of punishment.