Monkeys fail to reciprocate in an exchange task

Exchanges form the basis of human economies. Animals too can engage in reciprocal interactions but they do not barter goods like humans, which raises the question of the abilities necessary for trading to occur. Previous studies have shown that non-human primates can exchange food with human partners. Here, we tested the ability of brown capuchin monkeys and Tonkean macaques to reciprocate in a task requiring two conspecifics to exchange tokens in order to obtain rewards from an experimenter. We recorded 56 transfers between subjects in capuchin monkeys and 10 in Tonkean macaques. All transfers were passive in both species. Capuchins preferentially picked up tokens valuable for them in the partner’s compartment. They tended to manipulate the partner-valued tokens more often than the no-value ones, leading to more opportunities for these tokens to end up within reach of the partner. Despite optimal conditions where values of goods were defined and known by partners, however, none of the pairs tested engaged in short-term reciprocal interactions. These results indicate that calculated reciprocity was difficult if not impossible in the animals tested.     

Cognitive dissonance induced by writing a counterattitudinal essay facilitates performance on simple tasks but not on complex tasks that involve working memory

This article examines how performance is facilitated with simple tasks and is impaired with complex ones in individuals experiencing dissonance. Experiment 1 measured the performance of dissonance participants at a simple reaction time task. Reaction times were shortest in the dissonance condition. This facilitation effect was interpreted as resulting from increased arousal with dissonance. In Experiment 2, participants performed a more complex secondary memory task that required to memorize and to recall short and long series of numbers. Participants in the dissonance condition performed less well than participants in the no-dissonance condition only under a high memory load and did not differ with a low load. It is suggested that dissonance requires some working memory resources. Accordingly, it is assumed that the arousal properties of dissonance facilitate performance with simple task that do not involve working memory and require a dominant response, but that dissonance impairs performance with tasks that strongly involve working memory.     

Impact of interactivity on identification with characters in fiction

The effect of interactivity on identification with characters in audiovisual fiction was observed. 310 participants were asked to watch a film in one of these two conditions: 1) interactive (they selected the plot), and 2) non-interactive (they consumed the fiction in a conventional way). After watching the movie, they completed a questionnaire with the EDI scale of identification and empathy with characters, created by Igartua and Paez. The capacity to intervene in the configuration of the plot (interactivity) affected identification with characters. The results provide data about the psychology of media and interactivity in communication and allow us to understand the processes of empathy and identification with characters.     

The flexibility of source‐monitoring training: Reducing young children's source confusions

The effect of source‐monitoring training on the ability of 3‐ to 4‐year‐old children to discriminate between events seen live and those described in a story was examined. All children saw a live presentation of a target event and heard about a similar target event from a storybook. Three to 4 days later, the children received either source‐monitoring or control training involving a different set of events. Within each training condition, the children were taught to discriminate events (source training) or identify features of events (control training) acquired from sources that were either analogous (live–story events) or partially analogous (live—video events) to the target‐event sources. Immediately after training, all children were asked to monitor the source of the target events seen a few days earlier. The children in both the analogous and partially analogous source‐monitoring training groups more accurately distinguished between the target live and story events than did children in the control training groups. Copyright © 2009 John Wiley & Sons, Ltd.     

Variability in behavior frequencies and consistency in transactions across seasons in captive Japanese macaques (Macaca fuscata)

Consistent interspecific differences are found in macaque species, ranging from highly hierarchical and nepotistic societies to more tolerant and open social organizations. It still remains to be demonstrated whether intraspecific variation is narrower than interspecific variation. Herein, we quantified social behavior in a captive group of Japanese macaques (Macaca fuscata) to estimate the range of intraspecific variation for a full array of measurements in three different seasons. Despite an increased frequency of aggression found on the part of males during the mating season, the form of the behaviors performed remained relatively unchanged. Transactions during conflicts, approaches, or grooming did not undergo significant variations in relation to season. Frequencies and durations seemed more sensitive to demographic and environmental variations. The values measured in the study group are representative of the Japanese macaque. The results validate the use of transaction measurements in interspecific comparisons, providing that additional factors such as age and sex are taken into account. Aggr. Behav. 29:81–93, 2003. © 2003 Wiley‐Liss, Inc.     

Before and after the vocabulary spurt: two modes of word acquisition?

This paper focuses on early lexical development, and especially the period around 18 months known as the vocabulary spurt. We first propose that this period corresponds to a shift from an associationist to a referential lexical acquisition mechanism following the developmental coupling of specific pre‐linguistic and cognitive abilities. This latter mechanism would allow the acquisition of genuine words, i.e. links between phonetically specified sound patterns and object categories. We then review the literature on early lexical acquisition by typically developing infants and infants with Down and Williams syndrome, and report some data that were recently collected on this issue. We conclude that the data so far are congruent with our proposal, but because they remain insufficient, we propose some future research that focuses on the relation between pre‐linguistic and cognitive developments.     

Risk and protective factors at school: Reducing bullies and promoting positive bystanders' behaviors in adolescence

Identifying protective factors present at schools located in neighborhoods with high structural violence is fundamental to help prevent the perpetuation of violence . Therefore, the aim of this study was to observe how some school micro‐system variables, such as school environment and interpersonal relationships that adults establish with adolescents, may lead to bullying behaviors or, on the contrary, to positive bystander behavior in the bully‐victim dynamic. The sample was composed of 5,774 adolescents from 71 schools located in violent neighborhoods in Lima (Peru). 31.9 per cent of the sample experienced verbal violence and the prevalence of cyberbullying was 24.6%. Boys were more prone to experience both types of bullying than girls, although no differences were seen in the probability of becoming aggressors during early and late adolescence. The protective model showed that a positive atmosphere based on a supportive environment with clear rules encouraged adults at school to show more support and to provide more orientation in bullying situations, thus promoting a positive bystander behavior between peers. Opposite results were observed in the risk model. Actions at the micro‐system school level are discussed to enhance protective factors and reduce risk factors.     

Empowering Engineering Students in Ethical Risk Management: An Experimental Study

Science and Engineering Ethics - The complexity of industrial reality, the plurality of legitimate perspectives on risks and the role of emotions in decision-making raise important ethical issues...     

Models for a paraconsistent set theory

In this paper the existence of natural models for a paraconsistent version of naive set theory is discussed. These stand apart from the previous attempts due to the presence of some non-monotonic ingredients in the comprehension scheme they fulfill. Particularly, it is proved here that allowing the equality relation in formulae defining sets, within an extensional universe, compels the use of non-monotonic operators. By reviewing the preceding attempts, we show how our models can naturally be obtained as fixed points of some functor acting on a suitable category (stressing the use of fixed-point arguments in obtaining such alternative semantics).