Factors influencing the relation between extraversion and pleasant affect

Factors that influence the relation between extraversion and pleasant affect were examined in 6 studies. In Studies 1 through 5, the authors used structural equation modeling techniques to test whether different extraversion and pleasant affect scales and the use of multiple methods of assessment influenced the strength of the relation. In Study 6, the authors conducted a meta-analysis of previous literature to calculate an average effect size and to assess the influence of moderator variables. Results from both the structural equation models and the meta-analysis showed that with only a few exceptions, the use of different extraversion and affect scales resulted in moderate to strong correlations. The use of "on-line" methods of mood assessment (moment reports or daily-diary reports) resulted in lower and more homogeneous correlations than did the use of global, retrospective measures of mood.     

Can squirrel monkeys (Saimiri sciureus) learn self-control? A study using food array selection tests and reverse-reward contingency

Eight squirrel monkeys (Saimiri sciureus) were presented with 2 stimulus arrays, namely 1 and 4 pieces of food, but they received only the array other than the one they reached for. In this reverse-reward condition, all monkeys initially showed a strong preference for the larger array. One monkey learned to reach toward the smaller array when a large-or-none reward contingency was applied (i.e., no reward followed a reach toward the larger array, but this array was given for a reach toward the smaller array). When correction trials and time-out were added to the large-or-none procedure, all remaining monkeys except 1 learned this form of self-control. Performance was maintained when correction trials were discontinued, the original reverse-reward condition was rerun, and novel array-size pairs were presented. This study demonstrates one form of self-control in a New World primate and shows the reverse-reward procedure to be a potentially valuable method for assessing species and individual differences in self-control and numerosity-related abilities.     

Psychological distance reduces the effect of internalized stigma on mental health treatment decisions

Although stigma is a major barrier to treatment for those with mental health concerns, it is poorly understood when stigma is more or less influential in mental health treatment decisions. In the current work, we examined whether psychological distance—the removal of an event from direct experience—reduced the influence of internalized stigma on willingness to seek treatment. Specifically, we tested the hypothesis that psychological distance versus proximity (e.g., seeking treatment in three months vs. in two days, respectively) decreases the negative influence of stigma on willingness to seek treatment. We focused on a population for whom mental health treatment decisions are personally-relevant: individuals who had previously sought mental health treatment. Experiment 1 showed that the extent to which these individuals internalized (i.e., personally endorsed) stigma about mental illness predicted lower intentions to make an appointment with a mental health care provider for themselves (but not another person). Experiment 2 replicated this result using a different measure of psychological distance (temporal distance) and extended this finding to behavior (time spent reading mental health resources). Overall, this research demonstrated that internalized stigma disrupts mental health treatment-seeking intentions and behaviors when they are psychologically proximal, but not when they are distant. Potential applications of these results are discussed.     

Metamemory in tufted capuchin monkeys (Cebus apella)

Whereas evidence for metacognition by nonhuman primates has been obtained in great apes and old world monkeys, it is weaker in new world monkeys. For instance, capuchin monkeys may fail to recognize their own knowledge of the location of invisible bait. In the present study, we tested whether tufted capuchin monkeys would flexibly change their behavior in a delayed matching-to-sample (DMTS) test depending upon the strength of their memory trace of the sample. In Experiment 1, two monkeys were tested on a modified 9-alternative DMTS task with various delays on a computerized display. In some trials, the monkeys could choose whether to go for a memory test or for a simple key touch as an escape from the test. In other trials, they were forced to go for the memory test. Both monkeys escaped from the memory test more often when their matching accuracy on forced tests was lower. In one of the monkeys, the matching accuracies on chosen memory tests decreased more slowly as a function of delay length, and were higher after long delays than those on forced memory tests. This suggests that at least one capuchin monkey was able to recognize the strength of his own memory trace. Experiment 2 employed occasional no-sample tests, in which the monkeys faced the task choice without presentation of any sample for the trial. The monkey who was successful in Experiment 1 declined the memory test more often in no-sample trials than regular trials, further indicating metamemory in this individual. In Experiment 3, this successful monkey received a task, in which he was sometimes able to choose between shape MTS or texture MTS tasks. However, his matching accuracies did not differ between chosen tasks and forced tasks. Thus, the metamemory possessed by this new world monkey species may be more like a flag, showing strength of memory trace, than an elaborate representation showing details of the memory trace.     

High risk factors of hostage barricade incidents in a Japanese sample

Hostage taking incidents in which the police besiege a particular location are known as hostage barricade incidents. The first aim of the present article was to examine the process of risk assessment in hostage incidents, using a group of police officers as the sample. The second aim was to identify the risk factors involved in hostage incidents and examine the degree of concordance between the risk as assessed by the police officers and the figures obtained from the analysis of actual hostage barricade incidents. For the purpose of this study, a survey was carried out across Japan, and 45 police officers responsible for hostage negotiation responded to the questionnaires. Additionally, a sample of 116 actual hostage barricade incidents that occurred in Japan from 1970 to 2002 was utilised to examine the high risk factors involved in such cases. As per the results, a majority of the police officers (73.3%), in response to an open‐ended question, indicated that the highly excited state of the hostage takers was dangerous for the hostages. Moreover, it was demonstrated in all 116 incidents that several factors such as ‘a long siege’ tended to increase the risk of deaths, though this was very rare (n = 4). On the other hand, the proportion of injuries to the hostages was high in expressive situations such as domestic situations or suicide attempt scenarios. On the whole, the results obtained from the analyses of actual incidents were consistent with those obtained from the police officers' risk assessment in many respects. However, the correlation between the degree of risk as assessed by the police officers and the actual rate of deaths/injuries to the hostages was very low. Copyright © 2004 John Wiley & Sons, Ltd.     

Observational learning in capuchin monkeys: a video deficit effect

Young human children have been shown to learn less effectively from video or televised images than from real-life demonstrations. Although nonhuman primates respond to and can learn from video images, there is a lack of direct comparisons of task acquisition from video and live demonstrations. To address this gap in knowledge, we presented capuchin monkeys with video clips of a human demonstrator explicitly hiding food under one of two containers. The clips were presented at normal, faster than normal, or slower than normal speed, and then the monkeys were allowed to choose between the real containers. Even after 55 sessions and hundreds of video demonstration trials the monkeys’ performances indicated no mastery of the task, and there was no effect of video speed. When given live demonstrations of the hiding act, the monkeys’ performances were vastly improved. Upon subsequent return to video demonstrations, performances declined to pre-live-demonstration levels, but this time with evidence for an advantage of fast video demonstrations. Demonstration action speed may be one aspect of images that influence nonhuman primates’ ability to learn from video images, an ability that in monkeys, as in young children, appears limited compared to learning from live models.     

How do 8‐month‐old infants recognize causality in object motion and that in human action?1

Abstract: In Experiment 1, 8‐month‐old infants were first habituated to the event in which a moving object collided with another behind an occluder, then they were shown the two test events with no occluder: the contact event, in which the two objects actually collided, and the non‐contact event, in which the second object started to move without contact with the first. The infants looked at both events for an equal amount of time. In Experiment 2, in which the first object was a human actor, however, infants looked at the non‐contact event reliably longer than the contact event. In Experiment 3, in which both objects were human actors stood face‐to‐back, infants looked at the non‐contact event longer, whereas in Experiment 4, in which human actors faced toward each other, infants looked at both events equally. In Experiment 5, in which the first actor told the second to go, 10‐month‐old infants looked at both events for an equal amount of time. These results suggest that 8‐ and 10‐month‐old infants appreciate different causal principles between objects and humans, and that, in doing this, they may acknowledge the possibility of communication between humans.     

Learning from others’ mistakes in capuchin monkeys (<Emphasis Type="Italic">Cebus apella</Emphasis>)

We investigated whether tufted capuchin monkeys (Cebus apella) learn from others' mistakes. We prepared three kinds of transparent containers having the same appearance: one that could be opened by the lid, one that could be opened from the bottom, and one that could be opened either way. Using each of the first two one-way-open type containers, the monkeys were trained to copy the human demonstrator's action to open the container and obtain a piece of sweet potato contained therein. After this training, the demonstrator showed the monkeys an action that would open or fail to open the third, two-way-open type container. None of the monkeys reliably opened the container by spontaneously compensating for the demonstrator's failure (Experiment 1). In Experiment 2, the same subjects were trained to correct their own mistakes immediately after failure, before we introduced the same test as in Experiment 1. This experience did not result in subjects using the demonstrator's failure to produce a successful action. In Experiment 3, we placed two monkeys face to face. In this situation, the second monkey was presented with the container after the first monkey failed to open it. As a result, two capuchin monkeys capitalized on the partner's failure to correctly guide his/her behavior. Thus, the monkeys monitored not only the outcome of the others' action, but also that action per se. This result suggests that not only humans and apes, but also monkeys may understand the meaning of others' actions in social learning.     

Capuchin monkeys (Cebus apella) are sensitive to others’ reward: an experimental analysis of food-choice for conspecifics

The issue whether non-human primates have other-regarding preference and/or inequity aversion has been under debate. We investigated whether tufted capuchin monkeys are sensitive to others’ reward in various experimental food sharing settings. Two monkeys faced each other. The operator monkey chose one of two food containers placed between the participants, each containing a food item for him/herself and another for the recipient. The recipient passively received either high- or low-value food depending on the operator’s choice, whereas the operator obtained the same food regardless of his/her choice. The recipients were either the highest- or lowest-ranking member of the group, and the operators were middle-ranking. In Experiment 1, the operators chose the high-value food for the subordinate recipient more frequently than when there was no recipient, whereas they were indifferent in their choice for the dominant. This differentiated behavior could have been because the dominant recipient frequently ate the low-value food. In Experiment 2, we increased the difference in the value of the two food items so that both recipients would reject the low-value food. The results were the same as in Experiment 1. In Experiment 3, we placed an opaque screen in front of the recipient to examine effects of visual contact between the participants. The operators’ food choice generally shifted toward providing the low-value food for the recipient. These results suggest that capuchins are clearly sensitive to others’ reward and that they show other-regarding preference or a form of inequity aversion depending upon the recipients and the presence of visual contact.     

There’s no ball without noise: cats’ prediction of an object from noise

We used an expectancy violation procedure to ask whether cats could use a causal rule to infer the presence of an unseen object on hearing the noise it made inside a container and predict its appearance when the container was turned over. We presented cats with either an object dropping out of an opaque container or no object dropping out (turning-over phase) after producing either a rattling sound by shaking the container with the object inside, or no sound (shaking phase). The cats were then allowed to freely explore the experimental environment (exploration phase). The relation between the sound and the object matched with physical laws in half of the trials (congruent condition) and mismatched in the other half (incongruent condition). Inferring the presence of an unseen object from the noise was predicted to result in longer looking time in the incongruent condition. The prediction was supported by the cats’ behavior during the turning-over phase. The results suggest that cats used a causal-logical understanding of auditory stimuli to predict the appearance of invisible objects. The ecology of cats’ natural hunting style may favor the ability for inference on the basis of sounds.