Why night owls are more intelligent

The origin of values and preferences is an unresolved theoretical problem in social and behavioral sciences. The Savanna–IQ Interaction Hypothesis suggests that more intelligent individuals are more likely to acquire and espouse evolutionarily novel values and preferences than less intelligent individuals, but general intelligence has no effect on the acquisition and espousal of evolutionarily familiar values and preferences. Individuals can often choose their values and preferences even in the face of genetic predisposition. One example of such choice within genetic constraint is circadian rhythms. Survey of ethnographies of traditional societies suggests that nocturnal activities were probably rare in the ancestral environment, so the Hypothesis would predict that more intelligent individuals are more likely to be nocturnal than less intelligent individuals. The analysis of the National Longitudinal Study of Adolescent Health (Add Health) confirms the prediction.     

The meaningful life in Japan and the United States: Levels and correlates of meaning in life

Culture supplies people with the provisions to derive meaning from life. However, no research has examined cultural variation in the two principal dimensions of meaning in life, presence of meaning and search for meaning. The present investigation adapted theories of self-concept and cognitive styles to develop a dialectical model of meaning in life, which predicted cultural differences in the tendency to experience search for meaning as opposed to, or harmonious with, presence of meaning. Using data from American (N = 1183) and Japanese (N = 982) young adults, mean levels and correlates of presence of meaning and search for meaning were examined. As predicted, Americans reported greater presence of meaning; Japanese reported greater search for meaning. In accordance with the model, search for meaning was negatively related to presence of meaning and well-being in the United States (opposed) and positively related to these variables in Japan (harmonious). Thus, the search for meaning appears to be influenced by culture, and search for meaning appears to moderate cultural influences on presence of meaning.     

Tactics to obtain a hidden food item in chimpanzee pairs (Pan troglodytes)

Five dyads of chimpanzees were tested in a competitive situation, as a pilot study to examine chimpanzees' understanding of conspecifics' knowledge. A human experimenter baited one of five containers in an outdoor enclosure. Chimpanzee A (witness) could see where the food was hidden, while chimpanzee B (witness-of-witness) could not see the baited place but could observe the chimpanzee A watching the food being hidden. Then the two were released into the enclosure. This procedure was repeated for a certain number of days along with a control condition in which neither could see the baited location. The witness-of-witness developed tactics to forestall the witness in two pairs. The witness misled the witness-of-witness by taking a route to an empty container in several cases. These episodes might represent examples of deception. Tactics and counter-tactics thus developed through the interaction between the witness and the witness-of-witness, illustrating the high social intelligence of chimpanzees. An examination of the changes in tactics suggests a possibility that the witness-of-witness understands the witness's knowledge of the location of hidden food. Accepted after revision: 22 May 2001 Electronic Publication     

Enhanced uniform elongation by pre-straining with deformation twinning in high-strength β-titanium alloys with an isothermal ω-phase

It is shown that pre-straining with deformation twinning is a novel approach to enhancing the uniform elongation of a high-strength β-type Ti–15Mo alloy (mass%) with isothermal ω-phase precipitation. Pre-existent mechanical {3?3?2}?1?1?3? twins hinder the early onset of plastic instability (necking) after yielding, which is often caused by the presence of the isothermal ω-phase, and enhance the uniform elongation markedly from 0% to 13% at a yield strength level of 900?MPa.     

Childhood Adversity and Adulthood Subjective Well-Being: Evidence from Japan

In this study, we examined the impact of childhood interpersonal adversity on adulthood subjective well-being (SWB), with a focus on the mediating and moderating effects of social support and socioeconomic status (SES). We concentrated on parental maltreatment (abuse and neglect) and bullying in school as childhood adversity variables and on perceived happiness and self-rated health as adulthood SWB measures. Our empirical analysis was based on micro data from a survey in municipalities in and around the Tokyo metropolitan area (N = 3,292). We obtained four key findings. First, the experience of childhood adversity had a substantial negative impact on adulthood SWB. Second, social support and SES significantly mediated the impact of childhood adversity. Third, however, a large proportion of the impact of childhood adversity remained unexplained by their mediation effects. Fourth, social support and SES did not moderate the impact of childhood adversity. Hence, we can conclude that childhood adversity affects adulthood SWB in a relatively independent manner rather than being substantially mediated or moderated by social support or SES. Accordingly, social policies should aim at reducing incidents of childhood maltreatment and bullying in addition to helping people enhance levels of social support and SES in later life.     

Spatiotemporal dynamics of long-term potentiation in rat insular cortex revealed by optical imaging

Long-term potentiation (LTP) of the gustatory cortex (GC), a part of the insular cortex (IC) around the middle cerebral artery, is a key process of gustatory learning and memory, including conditioned taste aversion learning. The rostral (rGC) and caudal GC (cGC) process different tastes; the rGC responds to hedonic and the cGC responds to aversive tastes. However, plastic changes of spatial interaction of excitatory propagation between the rGC and cGC remain unknown. The present study aimed to elucidate spatiotemporal profiles of excitatory propagation, induced by electrical stimulation (five train pulses) of the rGC/cGC before and after LTP induction, using in vivo optical imaging with a voltage-sensitive dye. We demonstrated that tetanic stimulation of the cGC induced long-lasting expansion of the excitation responding to five train stimulation of the cGC, and an increase in amplitude of optical signals in the IC. Excitatory propagation after LTP induction spread preferentially toward the rostral IC: the length constant (λ) of excitation, obtained by fitting optical signals with a monoexponential curve, was increased to 121.9% in the rostral direction, whereas λ for the caudal, dorsal, and ventral directions were 48.9%, 44.2%, and 62.5%, respectively. LTP induction was prevented by pre-application of D-APV, an NMDA receptor antagonist, or atropine, a muscarinic receptor antagonist, to the cortical surface. In contrast, rGC stimulation induced only slight LTP without direction preference. Considering the different roles of the rGC and cGC in gustatory processing, these characteristic patterns of LTP in the GC may be involved in a mechanism underlying conversion of palatability.     

Haptic and visual influences on grasp point selection

When using precision grip to pick up objects, there are many possible pairs of grasp points that permit the thumb and index finger to exert opposed forces for secure grip. Previously, it was shown that individuals select grasp points so that the line between them (grasp axis) passes through or near the center of mass (CoM), thus minimizing the torque around the grasp axis during lifting. The accuracy of grasp axis selection depended on object spatial symmetry, indicating the importance of vision. The authors investigated how grasp point selection is influenced by haptic as well as visual information. Ten participants lifted cuboids whose CoM was located either symmetrically in the geometric center or asymmetrically toward one end. Results for the asymmetric cuboid revealed that grasp points migrated toward the asymmetric CoM from the geometric center. This was more pronounced in the presence of visual cues that reliably indicated the location of CoM. The results suggest that grasp point selection is influenced by a multimodal representation of CoM.     

Effects of temporal shapes of sound markers on the perception of interonset time intervals

This study investigated how the temporal characteristics, particularly durations, of sounds affect the perceived duration of very short interonset time intervals (120-360?ms), which is important for rhythm perception in speech and music. In four experiments, the subjective duration of single time intervals marked by two sounds was measured utilizing the method of adjustment, while the markers' durations, amplitude difference (which accompanied the duration change), and sound energy distribution in time were varied. Lengthening the duration of the second marker in the range of 20-100?ms increased the subjective duration of the time interval in a stable manner. Lengthening the first marker tended to increase the subjective duration, but unstably; an opposite effect sometimes appeared for the shortest time interval of 120?ms. The effects of varying the amplitude and the sound energy distribution in time of either marker were very small in the present experimental conditions, thus proving the effects of marker durations per se.     

Spill‐over effects of intermittent costs for defection in social dilemmas

This research investigates the role of intermittent monetary costs in restraining individuals from defection in social dilemmas. In Experiment 1, 104 car owners made fictitious choices between a slow and a fast travel mode in the context of a continuous social dilemma. There were four different conditions of monetary costs for choosing the fast mode (defection): no cost, low cost, high cost to self, or high cost to others. Participants defected most when there was no cost and least when they themselves were charged a high cost. A spill‐over effect was obtained such that when others were charged a high cost to defect, defection rates were lower than under no cost. Experiment 2 used 36 undergraduates as participants in an iterated decision task with real groups. The results replicated the major results of Experiment 1. Furthermore, whereas prosocials were strongly affected by intermittent costs for defection (i.e. showed large spill‐over effects), proselfs seemed to be unaffected. Possible explanations of this interaction effect between social value orientation and intermittent punishment for defection are provided. Copyright © 2002 John Wiley & Sons, Ltd.     

Why do people give? The role of identity in giving

Why do people give to others? One principal driver involves one's identity: who one is and how they view themselves. The degree to which identities are malleable, involve a readiness to act, and help make sense of the world have significant implications determining whether and how much people give. Drawing on the Identity-Based Motivation model (IBM; Oyserman, D. (2009). Identity-based motivation: Implications for action-readiness, procedural-readiness, and consumer behavior. Journal of Consumer Psychology, 19.), we provide a tripartite framework to help advance the research on the psychology of giving.