Evolution Of Social Relationships Research Articles

The Yellow-breasted Barbet (Trachyphonus margaritatus) introduces vocal duets and choruses with a specific multimodal signal, during territorial advertisement

Cooperative behaviour is a prominent feature among many group-living species and continues to pose challenges to our understanding about the evolution of social relationships and task coordination between members of the same social group. Individuals who are willing to cooperate to achieve a joined action need to communicate their intentions and somehow make a common agreement. We investigated how a coordinated chorus song is initiated in a cooperative-breeding bird species, The Yellow-Breasted Barbet (Trachyphonus margaritatus). A chorus can be defined as an interactive vocal display involving several individuals who are synchronizing their behaviour to sing in a time coordinated manner. Synchronizing behaviour to sing in chorus might become quite challenging when several individuals are involved. Thus, group members could use a specific signal to induce such collective action. Yet, few studies have investigated the mechanisms of communal display initiation in chorusing bird species. We conducted playback experiments to induce and record territorial defensive reactions from birds with a video camera. We recorded 26 different groups from distinct wild populations in Djibouti which belonged to 17 sites. We found that barbets use a specific vocalization named chewp note to introduce their duet and chorus. Moreover, we found that the individual that initiates such communal displays may broadcast a multimodal signal by combining chewp note series with a typical body posture with the tail raised and fanned. We suggest that the multimodal signal could serve to attract attention and elicit a response from other group members or could enhance the song coordination.

Evolution of social relationships between first-year students at middle school: from cliques to circles

People organize their social relationships under a restriction on the number that a single individual can maintain simultaneously (the so-called Dunbar’s number, ~150). Additionally, personal networks show a characteristic layered structure where each layer corresponds to relationships of different emotional closeness. This structure, referred to as Dunbar’s circles, has mostly been considered from a static viewpoint, and their structure and evolution is largely unexplored. Here we study the issue of the evolution of the structure of positive and negative relationships in early adolescence by using data from students in their first year at middle school obtained from surveys conducted in class in two different waves separated by several months. Our results show that, initially, students have a lower number of total relationships but the majority are more intense and over time they report a higher number of total relationships, but the more intense relationships appear in a lower proportion. We have also found differences in the structure of communities at both temporal moments. While in the first instance the communities that appeared are mixed, made up of both boys and girls, in the second they changed so that they were separated primarily by gender. In addition, the size of each community was stabilized around 15 people, which coincides with the size of the second Dunbar’s circle, known as the sympathy group in social psychology. As a consequence, in groups with around 20 students of the same gender, they tend to split in two separate communities of about 10 each, below the second Dunbar’s circle threshold. On the other hand, groups with more stable community structure appear to go through the inverse process of friendship evolution, becoming more focused on their best relationships. All these results suggest how the layered structure of the personal network, as well as the community structure of the social network, emerge directly from the union of both positive and negative relationships. Thus, we provide a new perspective about its temporal evolution that may have relevant applications to improve school life and student performance.

Usages - Source of Civil Law in the Regulation of the Romanian Civil Code

The role of custom in the formation of modern law is undeniable. The evolution of social relationships and structures, as well as the need for legal stability and predictability have diminished the importance of habit in ordering legal relations. The present study aims at analysing the role of custom in Romanian private law. The issue is particularly important, especially since the new Civil Code, which entered into force on October 1, 2011, mentions usage as a source of subsidiary civil law and subordinate to the law. Many authors considered this regulation to be an anachronistic one, a return to the past. However, through a careful analysis of the regulation contained in the Civil Code, it can be concluded that this was necessary from the point of view of uniformity in the application of international trade usages in the context of globalized trade. Thus, although custom has always played an extremely important role in public international law (e.g. diplomatic usages), there is a tendency to accept it as a distinct source of law in the legal relations of private law as well.

Social network service and social development in China

This study systematically traces the development of SNS (social network service) in China, and divides it into 4 stages: traditional networked socializing, the budding stage of SNS, the rapid growth of real-name socializing, and the thriving stage of socialized media. At the same time, the author analyses the characteristics of Chinese SNS in different stages. The study illustrates the role SNS has played in filling a gap of the traditional media, promoting social governance and economic development, by means of case studies of the high-speed train crash in Wenzhou, the protest of Wukan villagers in Guangdong, and the selling of green onions on Weibo (the Chinese version of Twitter). The study also theoretically explores how the SNS emerged and its relationship with social interaction and demonstrates that the difference between SNS and the traditional Internet is the identification of identity constructed by people-centered and social relationships. The changes in the way people use the Internet have an impact on the interaction structure of SNS and also on the evolution of social relationships on and off line, generating both positive and negative forces in the SNS development process. The SNS we expect is a rational and orderly social interaction structure which can promote continuous social progress.

Capitalism and Social Differentiation

In recent years numerous studies have been conducted in Ecuador with the objective of analyzing changes that have occurred, especially in the last two decades, in the rural social structure. These studies have given rise to a considerable mass of primary empirical material on a diversity of rural situations, and have resulted in the development of interpretive discussions of those changes surrounding the process of the transformation of the hacienda. We shall attempt to relate these results to the theme of rural social differentiation. We shall establish the relationship beginning, first, with a presentation and discussion of the ideas of Lenin and of Chayanov, exponents of opposing theoretical conceptions with respect to the evolution of social relationships in the countryside, and then we briefly review the dominant Ecuadorian interpretations of the processes of social differentiation. Finally, we examine statistical materials from the parish of San Gabriel in the province of Carchi, which we use to outline the processes that have affected peasant holdings, suggesting interpretations that lend specificity to our general notions of rural differentiation. With these notes we hope to call attention to certain important themes (such as the evolution of the peasant family) for the analysis of the processes of peasant social mobility, often underestimated in studies of capitalist rural development that emphasize strictly economic aspects of the process.