The primal warrior: Outgroup threat priming enhances intergroup discrimination in men but not women

Previous evidence suggests that, compared with females, male psychology and behavior is more strongly oriented toward intergroup conflict and competition. This study tested whether male coalitional psychology is so deeply ingrained that it could be activated even by subtle cues in the environment suggesting intergroup conflict. We used a priming method to test if being unwittingly exposed to an offensive message from an outgroup member in one type of intergroup context (i.e., inter-cultural) would enhance male’s and female’s intergroup discrimination in reward allocation in a completely irrelevant intergroup context (i.e., artificial laboratory group). The results showed that, as predicted, the outgroup threat priming enhanced discrimination in men but not women.     

Renewal of operant performance formerly eliminated by omission or noncontingency training upon return to the acquisition context

Renewal of operant performance formerly eliminated by omission or noncontingency training was explored in two experiments with rats. When pressing a lever was trained with food reinforcement in one context (A) and then eliminated in a second context (B), responding was renewed by returning the rats to the original context (A). This ABA renewal effect was demonstrated in Experiment 1 when the elimination training was an omission procedure (delivery of food for withholding responding) and in Experiment 2 when it was a noncontingency procedure (delivery of food irrespective of responding). Because omission training (differential reinforcement of other behavior) and noncontingency training have been used in applied settings as effective procedures to reduce undesired human behaviors, the clinical implications of our findings for the relapse of undesirable behavior were discussed.     

Group differences in the mutual gaze of chimpanzees (Pan troglodytes)

A comparative developmental framework was used to determine whether mutual gaze is unique to humans and, if not, whether common mechanisms support the development of mutual gaze in chimpanzees and humans. Mother-infant chimpanzees engaged in approximately 17 instances of mutual gaze per hour. Mutual gaze occurred in positive, nonagonistic contexts. Mother-infant chimpanzees at a Japanese center exhibited significantly more mutual gaze than those at a center in the United States. Cradling and motor stimulation varied across groups. Time spent cradling infants was inversely related to mutual gaze. It is suggested that in primates, mutual engagement is supported via an interchangeability of tactile and visual modalities. The importance of mutual gaze is best understood within a perspective that embraces both cross-species and cross-cultural data.     

Plasticity of ability to form cross‐modal representations in infant Japanese macaques

In a previous study, Adachi, Kuwahata, Fujita, Tomonaga & Matsuzawa demonstrated that infant Japanese macaques (Macaca fuscata) form cross‐modal representations of conspecifics but not of humans. However, because the subjects in the experiment were raised in a large social group and had considerably less exposure to humans than to conspecifics, it was an open question whether their lack of cross‐modal representation of humans simply reflected their lower levels of exposure to humans or was caused by some innate restrictions on the ability. To answer the question, we used the same procedure but tested infant Japanese macaques with more extensive experience of humans in daily life. Briefly, we presented monkeys with a photograph of either a monkey or a human face on an LCD monitor after playing a vocalization of one of these two species. The subjects looked at the monitor longer when a voice and a face were mismatched than when they were matched, irrespective of whether the preceding vocalization was a monkey's or a human's. This suggests that once monkeys have extensive experience with humans, they will form a cross‐modal representation of humans as well as of conspecifics.     

Visibility pattern of Bose–Fermi mixtures in one-dimensional incommensurate lattices

Abstract

We performed numerical simulations to demonstrate localization phenomena of Bose–Fermi mixture systems on incommensurate optical lattices by changing Bose–Bose and Bose–Fermi interactions. Visibility patterns of the bosons were measured to observe bosonic coherence in various selections of the interaction parameters. We found that the coherence was enhanced with repulsive Bose–Fermi interactions. It was also enhanced with attractive Bose–Fermi interactions but only in certain conditions. The enhancement by repulsive interactions and that by attractive interactions occurred with different mechanisms.