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Many animals devote substantial time, energy and resources to assessing nonmating social partners. However, relatively little is known about how individual characteristics influence the process and outcome of social partner choice. Social partner choice is an important aspect of Polistes fuscatus wasp lives, as nest-founding queens form and dissolve many short-term social relationships before settling down in stable cooperative groups. Here, we asked how personality and body size influence social partner assessment, the specific partners chosen, behaviour within social groups and group offspring production. We evaluated social and nonsocial personality traits (exploration, affiliation, aggression, investigation) and body mass in 75 individually marked queens, then released them in a large naturalistic enclosure where we recorded social partner assessment, nest founding behaviour and behaviour on nests. At the end of the season, we collected nests as a measure of group reproductive output. Exploratory personality had a stronger effect on social behaviour than other personality measures. More exploratory wasps sampled more social partners, joined nests later and spent fewer days as members of stable nests. Less exploratory wasps were more likely to become dominant on nests and were more aggressive after partnerships were established. Larger wasps sampled more potential nest sites, suggesting that sampling induces energetic costs that larger individuals are better able to bear. Among dominant and solitary-nesting wasps, more affiliative wasps built larger nests and more aggressive wasps built smaller nests. We did not find that wasps selected partners based on any measured trait. Overall, our work demonstrates that personality traits play an important role in how social partners are assessed, how social groups are formed, behaviour within established social groups and the success of social groups. Our study also suggests that personality mediates a trade-off between time spent sampling partners and social bond stability. • We evaluated effects of personality and body size on social partner choice in wasps. • More exploratory wasps sampled more social partners and joined nests later. • They spent fewer days in stable groups and were less likely to be dominant on nests. • Body size and social personality had little effect on partner assessment. • Personality may mediate a social assessment–stable social bond trade-off. [ABSTRACT FROM AUTHOR]

Social organization is characterized by its stability. Researchers consistently observe distinct social relationships (e.g. mated pairs, friendships and rivalries) and higher-order social network structures (e.g. subgroups, transitivity and dominance hierarchies) across time and space. Nevertheless, group change is also ubiquitous, and the social composition of groups fluctuates over time and across generations. Despite this, little is known about the processes underlying the stability of social organization, especially across generations. This paper proposes that understanding the development of social relationships, or socialization, provides key insights into the stability and flexibility of group social organization. I propose that stable patterns of social organization can be conceptualized as a feedback system, where the social organization of groups renews itself by guiding the socialization of resilient species-normative relationships in juveniles. I outline a general framework of socialization that includes exploring, pruning and consolidating early social connections to form stable relationships. During this socialization process, outside influences from the group guide how juveniles explore their social environment, which social connections are reinforced and which behavioural skills are used to consolidate connections. When the social relationships that define the group's organization directly or indirectly guide the socialization of juveniles to recreate those relationships, the result is stable patterns of social organization. This developmental perspective provides mechanistic insights into how social organization persists in an uncertain world and highlights how developmental processes may be a crucial, and overlooked, factor in shaping the stability and flexibility of social organization. • Social organization is characterized by its stability. • I propose that socialization is a key process of group stability/flexibility. • Socialization includes exploring, pruning and consolidating early social connections. • Social organization and socialization can be conceptualized as a feedback system. • This feedback system renews resilient species-typical relationships over generations. [ABSTRACT FROM AUTHOR]

The interest in better understanding the characteristics and drivers of food consumption by individuals and social groups has grown in recent years, because of various social, environmental, health and economic issues. Most analyses have focused either on the macro or national scale, using food balance/disappearance data, or on the micro scale, focusing on nutrition analysis in limited groups of individual consumers. While various household characteristics are expected to influence food-purchasing habits, the scope and methodology of most previous studies limited their ability to relate to multiple factors, and integrate all into specific consumption patterns. A third, mezzo approach focuses on analyzing household food purchasing, mostly using expenditure surveys. However, focusing on the value spent may result in different quantities of food purchased. This paper aims capturing the amount of food purchased by Israeli households and to analyze the socio-economic factors shaping that consumption. It joins limited number of studies worldwide that focused on the quantity purchased, and the first such analysis of household food purchasing in the State of Israel. It quantified food purchased by more than 30,000 households, and analyzed key shaping factors e.g., income, household size and age. It first, established the need for quantity based analysis. Then, an extensive breakdown of consumed food is presented and the unique diets of different parts of the society were identified. Finally, it examined the consumption of different lifestyles to find that couples lifestyles tend to consume more per capita, and that income has a crucial role in determining the rate of consumption both in terms of quantity and variety purchased. However it highlights that other variables should also be examined in order to assess properly why households consume the way they do. Nevertheless, the findings of this research can be used as the basis for examining the health, social, or environmental implications of the different identified food consumption habits, support long-term research that examines changes over time, and may be the basis for examining the potential benefits of implementing specific policies. [ABSTRACT FROM AUTHOR]

In this paper, we address the question of the conditions for persistence of technological boundaries. We use field studies to test the predictions generated by a theoretical model in analytical sociology and examine the micro-processes at stake in the non-diffusion of techniques: to which extent techniques contributes to a sharp disagreement between groups and promote polarization? The ultimate goal is to provide archaeologists with an empirically tested model to explain spatial distribution of technological clusters and maintenance of technological boundaries. Field studies examine ethnographic situations in four countries where social groups using different ceramic techniques for making utilitarian vessels live in close geographical proximity. Two situations enable us to examine the conditions under which technological boundaries persist, while two others enable us to analyze, through a boundary-making perspective, how differences in craft techniques contribute to polarization. Our data suggest that in a context where different techniques are used for different types of object there is a cognitive bias which fosters technological polarization. This cognitive bias develops in the course of interactions between actors living in close geographical proximity. Polarization increases when technological standards are used by different social groups, thereby favoring negative influence and persistent technological boundaries. [ABSTRACT FROM AUTHOR]

Abstract: Individuals who qualify equally for membership in more than one racial group are not judged as belonging equally to both of their parent groups, but instead are seen as belonging more to their lower status parent group. Why? The present paper begins to establish the role of individual differences and social context in hypodescent, the process of assigning multiracials the status of their relatively disadvantaged parent group. Specifically, in two experiments, we found that individual differences in social dominance orientation—a preference for group-based hierarchy and inequality—interacts with perceptions of socioeconomic threat to influence the use of hypodescent in categorizing half-Black, half-White biracial targets. Importantly, this paper begins to establish hypodescent as a “hierarchy-enhancing” social categorization. [Copyright &y& Elsevier]

Studies of social networks have often taken the existence of a social tie as a proxy for the transmission of information. However, other studies of social networks in the labor market propose that the likelihood of information transmission might depend on strength of the tie; and that tie strength is a potentially important source of the tie's value. After all, even if job seekers have social ties to those who have valuable job information, the seekers will gain little information benefit when the ties do not actually transmit the information. This paper clarifies the conditions under which social ties might provide information benefits. We use a survey vignette experiment and ask MBA students about their likelihood of relaying job information via strong ties (to friends) or weak ties (to acquaintances), holding constant the structural locations spanned by the tie and job seekers' fit with the job. The results support the claim that strength of tie has a causal effect on the chances of information transmission: potential referrers are more likely to relay job information to their friends than to acquaintances. The larger implication of these findings is that whatever benefits there might be to using weak ties to reach distant non-redundant information during job search, these benefits need to be considered against the likely fact that people connected via weak ties are less likely to actually share information about job opportunities than are people to whom the job seeker is strongly tied. [ABSTRACT FROM AUTHOR]

Abstract: This paper studies the first model of social interactions with anti-coordination. Agents have fixed partners with whom they play a common bilateral game of anti-coordination, like the chicken game. Partnerships are represented as links of a network. The paper asks: How do social interactions interplay with the incentives to anti-coordinate? How does the social network affect individual choices in equilibrium? The analysis shows that network effects are much stronger than when partners play a coordination game. The network notably affects how agents respond when a strategy becomes more advantageous. In the standard benchmark of complete interactions, more agents play the strategy. This result does not generally hold when the network is incomplete. On bipartite networks, agents'' choices are unaffected, while on core-periphery networks, less agents may play the strategy. [Copyright &y& Elsevier]

Abstract: The colonial census was a bureaucratic device which provided an essential abstraction from social reality, a ‘statistical fix’ designed to map individual social groups in space. This paper considers the contradictions associated with colonial knowledge systems as reflected in the census grafted onto Burmese society in the nineteenth and early twentieth centuries. It attempts to chart the general adoption and adaptation, in the Burmese context, of a classificatory scheme which categorised labour as either productive or unproductive. Colonialism introduced new attitudes towards work and labour which reinforced patriarchal values which contrasted with more egalitarian Burmese socio-economic systems. The paper suggests that a simple classification of women workers as either productive or unproductive in the Burmese census between 1872 and 1931 resulted in the devaluation of their status as workers. This devaluation was a function of both real economic transformation taking place in the empire and changes in census classification, reflecting a gendering of occupations that undermined the cultural norms of Burmese society. The material result was that women became statistically less visible as economically productive workers. Such ascriptions of value to women workers were largely informed by moral considerations originating in England. [Copyright &y& Elsevier]

Many urban theorists, notably W.J. Wilson, hypothesize that rates of male joblessness in low-income urban neighborhoods have increased since the 1960s. This paper examines this claim by tabulating male employment trends in census tracts in 49 metropolitan areas from 1950 to 1990, and models causes of these trends. The results show a marked decline in the employment of working-age men in low-income black tracts, both in absolute terms and relative to the employment rates of male residents of other types of tracts. This decline occurred among cities in all regions of the country. By 1990, more than 40% of working-age black men in low-income tracts were not employed, about two-thirds of whom were adults between the ages of 25 and 64. Models indicate that declining urban manufacturing employment contributed to the declining rates of work for black men in low-income neighborhoods, but they do not support explanations based on spatial mismatch, suburbanization, or black out-migration. The paper concludes that Wilson is right to focus on the employment problem of low-income black neighborhoods, and that black male joblessness in low-income neighborhoods in 1990 reached crisis levels. [ABSTRACT FROM AUTHOR]

This article is part of a Special Issue “Chemosignals and Reproduction” Across phyla, chemosensory communication is crucial for mediating a variety of social behaviors, which form the basis for ontogenetic and phylogenetic survival. In the present paper, evidence on chemosensory communication in humans, with special reference to reproduction and survival, will be presented. First, the impact of chemosignals on human reproduction will be reviewed. Work will be presented, showing how chemosensory signals are involved in mate choice and partnership formation by communicating attractiveness and facilitating a partner selection, which is of evolutionary advantage, and furthermore providing information about the level of sexual hormones. In addition to direct effects on phylogenetic survival, chemosignals indirectly aid reproductive success by fostering harm protection. Results will be presented, showing that chemosensory communication aids the emotional bond between mother and child, which in turn motivates parental caretaking and protection, leading to infant survival. Moreover, the likelihood of group survival can be increased through the use of stress-related chemosignals. Stress-related chemosignals induce a stress-related physiology in the perceiver, thereby priming a fight–flight-response, which is necessary for an optimum adaption to environmental harm. Finally, effects of sexual orientation on chemosensory communication will be discussed in terms of their putative role in stabilizing social groups, which might indirectly provide harm protection and foster survival. An integrative model of the presented data will be introduced. In conclusion, an outlook, focusing on the involvement of chemosensory communication in human social behavior and illustrating a novel approach to the significance of chemosensory signals in human survival, will be given. [ABSTRACT FROM AUTHOR]

Abstract: Although generally accepted in the literature on group diversity, the view that groups can improve their creativity by drawing on the diverse perspectives of group members has received surprisingly limited examination or empirical support. This paper considers the role of deep level diversity in group creativity, highlighting that while deep diversity may improve divergent processes in groups, it may also hamper groups' ability to converge around creative ideas. Two experimental studies demonstrate that deep level diversity leads to less creatively elaborated and integrated ideas. In addition, the studies revealed that when groups must converge around a single output, the challenges of deep level diversity outweigh the benefits of divergent idea generation. A detailed analysis of the interactions of 27 groups finds that this effect occurs because deep diversity changes a group's creative process. This study contributes to our understanding of the creative process in groups with detailed analysis of video-taped group interactions. It challenges the assumed advantages of deep level diversity to group creativity, and suggests that the brainstorming process that groups are typically advised to use to promote creativity may not be the best way to develop creative final output. [Copyright &y& Elsevier]

• Three early Medieval (12th c. AD) house deposits are examined from Croatia. • Explores how identity may manifest itself through individual/collective practice. • The results suggest shared 'folk' beliefs had a valued place in Dalmatian society. • The objects go beyond symbols of apotropaic magic but served multiple purposes. This paper examines three early medieval ritual house deposits from Bribirska glavica, Dalmatia, Croatia. Discovered over the last century these items bring to the fore questions regarding the relationship between state and secular religion in a region that experienced numerous encounters and confrontations within and between different social groups. This paper explores these complexities using the term 'religious imaginaries' to describe how a sense of collective identity may manifest itself through individual and collective practice, focusing on the value of the discovered objects (chickens, eggs, whetstones and plant remains) and their ritual framings. In particular, the recovery of archaeobotanical remains highlights the importance of examining plant use in ritual deposits. Overall, despite some variation in the interpretations of the practice of 'special' offerings, the majority of studies draw the conclusion that items hidden in this manner provide a broadly protective or apotropaic function. Thus, these finds provide important insights into the development of religious and ritual beliefs in early medieval Dalmatia, suggesting that the community's religious imaginary comprised a set of values and symbols that hybridised the Christian faith with elements of 'folk magic' to re-inforce the apotropaic power of their ritual acts. [ABSTRACT FROM AUTHOR]

• Ancient Egypt provides insights on local responses to political and social changes. • Changes were not all gradual and were part of interacting, dynamic, multiscalar adaptive cycles. • Inhabitants at Tell el-Dabˁa reacted and (re-)adapted via short- and long-term strategies. • Strategies include fostering community, negotiating cultural elements, and developing networks. Ancient Egypt is considered as one of the world's longest enduring civilisations, yet few studies have explored its history for insights on community resilience in response to institutional and social change. Instead of focussing on the collapse of the central Egyptian administration, this paper centres its analysis on a 'community' in the northeast of Egypt at ancient Avaris, modern Tell el-Dabˁa. Using resilience theory as metaphor, it provides an overview of developments at the site, observing periods of relative stability punctuated by those of accelerated change. It addresses how different social groups transformed in light of social and political developments by (re-)negotiating cultural elements as well as their local, regional, and supra-regional ties, and whether and how these may be interpreted as short- and long-term strategies of 'survival'. [ABSTRACT FROM AUTHOR]

Abstract: This paper tests the competing hypotheses that social dominance orientation (SDO) reflects a specific desire to protect ingroup interests vs. a general desire to maintain status hierarchies by examining attitudes toward hierarchy-enhancing (i.e., legacy) and hierarchy-attenuating (i.e., affirmative action) selection policies. Study 1 found that social dominance orientation (SDO) was positively related to support for legacy policies and negatively related to support for affirmative action. In a more direct test of the ingroup interest vs. general dominance hypotheses, Study 2 found that among Asian participants, SDO is negatively related to policy support when a legacy policy is perceived to benefit the ingroup (i.e., fellow Asians); however, when the policy is perceived to benefit the dominant group (i.e., Whites), SDO is positively related to support. In all, these findings suggest that attitudes toward selection policies depend not on their specific content or effects on the ingroup, but rather on their impact on status hierarchies. [Copyright &y& Elsevier]

Abstract: What explains the large variation in the number of contacts (degree) that different participants of social networks have: age, randomness, or some unobservable fitness measure? To answer this question, I extend the model presented in Jackson and Rogers (2007) to allow individuals to vary in their ability to attract contacts. I estimate the parameters of the extended model, using a social network of citations among high-energy physics papers, and find that the extended Jackson–Rogers model can parsimoniously fit the degree distribution of each age cohort. Moreover, both the length of time spent in the network and the unobservable fitness measure are important in explaining the observed variation in participantsʼ degrees. [Copyright &y& Elsevier]

Abstract: Recent research suggests that contemporary human social groups are structured according to principles of fission and fusion that are also observed in some of our primate relatives, raising the possibility that such social systems have been a feature of hominin society throughout prehistory. The current paper examines the possibility of identifying archaeological signatures of multi-level social structures through the examination of site size distributions. Data on the sizes of Irish Bronze Age stone circles and predictions for the size of aggregations they could accommodate are compared with simulations parameterized using data on modern human groups. The results suggest that the presence of hierarchically inclusive, multi-level social structures provides a better explanation for the data than more traditional archaeological accounts based on the rank-size rule and related inferences concerning the emergence of political elites. [Copyright &y& Elsevier]

The U.S. residential landscape is increasingly multi-racial and multi-ethnic, giving rise to the question of how to compare dichotomous segregation among multiple groups living in the same area. To address the problem in the existing dichotomous approach, which offers no common basis for comparing dichotomous segregation among multiple groups, this paper develops a weighted segregation ratio approach based on Theil’s segregation index and its additive decomposability. This approach can be used to bridge information obtained from dichotomous segregation between specific groups (such as black–white and black-Hispanic), and dichotomous segregation between group and non-group (such as white–non-white and black–non-black) in previous studies. We apply both dichotomous and weighted segregation ratio approaches to 1990 and 2000 U.S. census data. Results are interpreted for five selected metropolitan areas as well as for the weighted national average. This new approach yields distinctive findings that portray the complicated process of residential segregation, including the increasing significance of Hispanic segregation and Asian segregation in the decade from 1990 to 2000. [Copyright &y& Elsevier]

Abstract: Intra-group cooperation in a social dilemma is increased after a group has discussed and reached a decision, especially if the dilemma is easily understood (‘demonstrable’). This paper examines how demonstrability affects the decision of a group that consists entirely of participants who are initially non-cooperative. Thirty-eight 6-person groups with unanimous prior preference for cooperation or non-cooperation discussed a prisoner’s dilemma before making a group decision. When demonstrability was low groups reflected the prior (either cooperative or non-cooperative) preferences of their members. When demonstrability was high we found that groups showed no effect of prior preference. Specifically, groups of prior non-cooperators made more cooperative group decisions and subsequently their members remained cooperative when asked to express preferences individually. The combined advantages of group process and high demonstrability for facilitating optimal cooperation are discussed. [ABSTRACT FROM AUTHOR]

Abstract: The paper investigates the formation of information sharing communities. The environment is characterized by the anonymity of the contributors and users, as on the Web. Furthermore information exchange is limited to simple recommendations. When preferences differ, it is argued that a community may be worth forming because it facilitates the interpretation and understanding of the posted information. The admission rule within a community, the quality of information, and the stability of multiple communities are examined. [Copyright &y& Elsevier]

Abstract: Is a mathematical problem a cultural invariant, which would invariably give rise to the same practices, independent of the social groups considered? This paper discusses evidence found in the oldest Chinese mathematical text handed down by the written tradition, the canonical work The Nine Chapters on Mathematical Procedures and its commentaries, to answer this question in the negative. The Canon and its commentaries bear witness to the fact that, in the tradition for which they provide evidence, mathematical problems not only were questions to be solved, but also played a key part in conducting proofs of the correctness of algorithms. [Copyright &y& Elsevier]

Abstract: The distribution of success and failure to social groups is supported by lay theories about the characteristics of social groups and the causes of their outcomes, as well as by beliefs about entitlement of groups to succeed or fail. This paper presents a study where a target individual’s socio-economic status (high vs. low) and outcome in a major academic achievement task (success vs. failure) were manipulated in a 2×2 experimental design. It was found that high-status success and low-status failure, i.e. the system-consistent outcomes, were attributed relatively more to stable internal causes (ability), whereas high-status failure and low-status success, i.e. the system-inconsistent outcomes, were attributed relatively more to unstable causes (effort). Second, participants’ belief in a just world was higher in high-status success and low-status failure than in high-status failure and low-status success. [Copyright &y& Elsevier]

Abstract: Extant literature in developmental psychology has documented the co-occurrence of aggressive and affiliative behaviors with various measures of social dominance. While these findings have been taken as evidence for the functional value of aggression, they have not been integrated into a more general theoretical frame accounting for contextual variation. In this paper the literature on aggression, agonism, affiliation, and social dominance is reviewed in light of behavioral ecological theory suggesting that different forms of competition (scramble and contest) determine, respectively, the use of affiliative and aggressive strategies. Results generally support the hypotheses advanced by this theory. In order to further integrate these findings suggestions for the study sequences of behavior, where reconciliations follow aggression, are made. [Copyright &y& Elsevier]

This paper applies an innovative approach to monitoring social effects occurring before and during construction of two hydroelectric dams in Canada. The two studied dams, Site C and Keeyask, are under construction in Canada and underwent community-based impact assessment (CBIA). News coverage and the CBIA documents were analyzed to understand and compare how those two groups perceive social effects induced by the two projects. CBIAs contain concerns expressed by affected people, whereas news coverage can include quotes from both affected people and decisionmakers involved in the assessment process. By contrasting these datasets, we found that the documents are complementary: while CBIAs are comprehensive in assessing community concerns, news outlets can reveal how those concerns evolved throughout different phases of the projects' implementation. This approach fills a gap in SIA around monitoring of key social effects around local conflicts and disputes, psychosocial effects, socioeconomic effects, and cumulative effects on a daily life. Furthermore, by contrasting the views identified within the impact assessments and the media, the study demonstrates how specific concerns diverged: affected people focus on local social effects while decisionmakers' interests lie in a broader political perspective grounded in local sacrifices 'for the good of the whole province'. Our analysis emphasizes the role of political power over decision making that can inhibit CBIA and social impact assessment practice from contributing to socially sustainable projects. • News outlets can be used to monitor social effects from infrastructure projects. • Community assessments tend to address more chronic effects while news media coverage focuses on episodes of conflicts. • Pollical power over decision-making might inhibit more sustainable projects. [ABSTRACT FROM AUTHOR]

While inequality between individuals is known to be an important determinant of redistributive preferences, research on inequality between groups has increased only recently. This paper argues that individuals infer income expectations from the economic standing of their social group, in particular groups based on characteristics determined at birth, such as sex, race, or parents class. High group incomes can lead individuals to oppose redistribution, even if they are currently poor. Analyses of US survey data from 1978 to 2014 support this argument. The uncovered effects on preferences exceed those of individual income by more than three times in magnitude. [ABSTRACT FROM AUTHOR]

Abstract: Contending with negative intellectual stereotypes has been shown to depress the academic performance of targets of the stereotypes [Steele, C. M. (1997). A threat in the air: How stereotypes shape intellectual identity and performance. American Psychologist, 52, 613–629]. The present paper examines whether women’s mathematics performance is differentially affected by the concern of confirming that a negative stereotype is true of the self (self-threat), than by the concern of confirming that the stereotype is true of their gender (group-threat). In two studies we independently manipulated these different threats for women taking a mathematics test. Gender identification moderated the effect of group-threats on test performance; only women highly identified with their gender underperformed. The performance of less gender-identified women was unaffected by group-threats. In contrast, gender identification did not moderate the effect of self-threats—both high- and low-identified women underperformed. The results of these studies suggest that women’s math performance is differentially affected by the source of the threat. [Copyright &y& Elsevier]

Abstract: In this paper we consider linear Schrödinger operator with double or resonant eigenvalues. The main result is the bound of the measure (in a suitable space of functions) of the potentials leading to such double or resonant eigenvalues. Namely we present measure type estimates evaluating neighborhoods of the so-called double or resonant set. [Copyright &y& Elsevier]

Abstract: In this paper, we consider a class of stochastic wave equations with nonlinear multiplicative noise. We first show that these stochastic wave equations generate random dynamical systems (or stochastic flows) by transforming the stochastic wave equations to random wave equations through a stationary random homeomorphism. Then, we establish the existence of random invariant manifolds for the random wave equations. Due to the temperedness of the nonlinearity, we obtain only local invariant manifolds no matter how large the spectral gap is unlike the deterministic cases. Based on these random dynamical systems, we prove the existence of random invariant manifolds in a tempered neighborhood of an equilibrium. Finally, we show that the images of these invariant manifolds under the inverse stationary transformation give invariant manifolds for the stochastic wave equations. [Copyright &y& Elsevier]

Abstract: This paper reconciles the inconsistent findings on the interactive effect of interactional justice and social comparison information on outcome evaluation. We distinguish two different effects of interactional justice and examine outcome uncertainty as a qualifying factor. Three hundred and fifty-seven undergraduates participated in a scenario experiment. It is found that, due to the functional quality effect, interactional justice significantly influences outcome evaluation, regardless of the social comparison information that is available, in situations of low outcome uncertainty. However, due to the fair process effect, interactional justice, as with procedural justice, interacts with social comparison information to influence outcome evaluation in situations of high outcome uncertainty. Implications for comparison referents and social comparison motives in social justice research are discussed. [Copyright &y& Elsevier]

Abstract: Status generalization has been described as a process directly linking social status at the societal level to influence in interpersonal interactions, providing one mechanism through which status inequalities in society are maintained. It is argued in this paper that groups can moderate status generalization when a status characteristic is non-prototypical of the group. Two experiments are reported that measured the relative influence of an older and younger target within different group contexts: an undergraduate student group and a broader university group. In both experiments, the older target was more influential than the younger target in the context of the university group, but the younger target was more influential in the context of the undergraduate student group. Findings are discussed in relation to status generalization and referent informational influence as separate influence processes. [Copyright &y& Elsevier]

Abstract: The importance of risk-monitoring has been increasing in many key aspects of our modern lives. This paper examines how individuals monitor such risks collectively by extending a behavioral ecological model of animal foraging to human groups. Just as animals must forage for food under predatory risk, humans must divide valuable material and psychological resources between foraging activity and risk-monitoring activity. We predicted that game-theoretic aspects of the group situation complicate such a trade-off decision in resource allocation, eventually yielding a mixed equilibrium in a group. When the equilibrium is reached, only a subset of members engage in the risk-monitoring activity while others free-ride, concentrating mainly on their own foraging activity. Laboratory groups engaging in foraging under moderate risk provided a support to this prediction. When the risk-level was set higher, however, “herding behavior” (conforming to the dominant behavior) interfered with the emergence of equilibrium. Implications for risk management are discussed. [Copyright &y& Elsevier]

Abstract: Feasts provide a public forum where social statuses can be affirmed or challenged among pre-state societies. Documenting feasting behavior thus provides insight into the construction of prehistoric political power. This paper presents expected material patterns of feasting by focusing on intra-site variability in food preparation, presentation, and consumption. Expectations are evaluated by comparing ceramic, ground stone, obsidian, and faunal data recovered from Conchas phase (900–800 BCE) elite and village midden deposits at Cuauhtémoc in the Soconusco region of southern Mexico. I argue that elite feasting at Cuauhtémoc created political cohesion between elite and non-elite segments of society during the Conchas phase as a new polity emerged that was more socially stratified and politically hierarchical than anything previously known in the region. [Copyright &y& Elsevier]

Abstract: Research on neighborhood effects on youth educational outcomes has been mainly an American tradition. This study reviews the European evidence on this subject and brings new evidence, focusing on Helsinki, the capital of Finland. Register-based data and multi-level statistical analysis are used to assess the existence and form of neighborhood effects on the educational careers of young people in Helsinki. The results indicate that there is no effect on the completion of secondary education generally, but there is an effect on the type of education that is completed. This effect is nonlinear: the affluent neighborhoods differ from the rest of the neighborhoods. The paper concludes by stating that research on neighborhood effects should better recognize the existence of “soft” effects. [Copyright &y& Elsevier]

Abstract: Traditional proofs of the Pontryagin Maximum Principle (PMP) require the continuous differentiability of the dynamics with respect to the state variable on a neighborhood of the minimizing state trajectory, when arbitrary values of control variable are inserted into the dynamic equations. Sussmann has drawn attention to the fact that the PMP remains valid when the dynamics are differentiable with respect to the state variable, merely when the minimizing control is inserted into the dynamic equations. This weakening of earlier hypotheses has been referred to as the Lojasiewicz refinement. Arutyunov and Vinter showed that these extensions of early versions of the PMP can be simply proved by finite-dimensional approximations, application of a Lagrange multiplier rule in finite dimensions and passage to the limit. This paper generalizes the finite-dimensional approximation technique to a problem with state constraints, where the use of needle variations of the optimal control had not been successful. Moreover, the cost function and endpoint constraints are not assumed to be differentiable, but merely locally Lipschitz continuous. The Maximum Principle is expressed in terms of Michel–Penot subdifferential. [Copyright &y& Elsevier]

Abstract: This paper continues the study of Mao et al. investigating two aspects of the equation The first of these is to slightly improve results in [X. Mao, S. Sabais, E. Renshaw, Asymptotic behavior of stochastic Lotka–Volterra model, J. Math. Anal. 287 (2003) 141–156] concerning with the upper-growth rate of the total quantity of species by weakening hypotheses posed on the coefficients of the equation. The second aspect is to investigate the lower-growth rate of the positive solutions. By using Lyapunov function technique and using a changing time method, we prove that the total quantity always visits any neighborhood of the point 0 and we simultaneously give estimates for this lower-growth rate. [Copyright &y& Elsevier]

Abstract: In this paper, we describe the development and implementation of the multilevel sample design for the Los Angeles Family and Neighborhood Survey, a study of children, adults, families, and neighborhoods in Los Angeles County. This survey was designed to support multilevel analyses on a number of topics, including child development, residential mobility, and welfare reform. We describe the design of the baseline wave, highlighting the analytical and statistical issues that shaped the study. We also present the results of an in-depth statistical investigation of the survey’s ability to support multilevel analyses that was carried out as part of the study design. The results of this study provide important guideposts for future studies of neighborhoods and their effects on adults and children. [Copyright &y& Elsevier]

Abstract: Researchers have established that individual religiosity influences sexual behavior and that religious support can increase consistency between personal religiosity and behavior. Researchers are less certain, however, of the effect that religious friendship networks have on sexual behavior. In addition, the effects of network characteristics such as density and one’s position in a social network have not been established. This paper uses a network subsample of the National Longitudinal Study of Adolescent Health (Add Health) to examine the effect of friends’ religiosity on the probability of first sex. We find that friends’ religiosity has an independent influence on adolescent sexual behavior that is similar in magnitude to personal religiosity. We also find evidence that friends’ religiosity has the strongest influence on the sexual behavior of adolescents who are embedded in dense social networks, in which teens’ friends are also friends with one another. These results support the hypothesis that group influences depend on the degree of embeddedness within the network and highlight the importance of studying religion as a property of groups as well as individuals. [Copyright &y& Elsevier]

Abstract: Over the last several decades increases in the income inequality in the United States have been well-documented. Yet, this assessment of growing prosperity for some but downslide for others is based on a specific interpretation of the concept “inequality.” This paper develops an alternative measure of inequality based on the concept “relative deprivation.” Relative deprivation refers to the frustration that is associated with a person’s relative position in a reference group. The proposed measure draws from the social science literature on poverty and improves upon an earlier measure, RD. Using data from the 1998 General Social Survey, I analyze the relationship between the proposed and earlier measures of relative deprivation, and two outcome variables: (1) self-rated health, and (2) happiness. While the measures produce similar results in predicting self-rated health, the proposed measure is a better predictor of happiness than the earlier measure. I conclude that the empirical and theoretical advantages of the proposed index make it an improved measure of relative deprivation. [Copyright &y& Elsevier]

Abstract: In this paper, we consider how concepts from dynamic systems (such as attractors, repellors, and self-organization) can be applied to the study of young children’s peer relationships. We also consider how these concepts can be used to explore basic issues involving early peer processes. We use the dynamical systems approach called state space grid (SSG) analysis and consider how it can be expanded beyond the study of dyads to the study of larger social groups and networks. In particular, we explore the role of homophily—that is, behavioral and sex similarity—as factors in the self-organization of young children’s social groups. A dynamic systems approach allows for consideration of peer processes difficult to assess using more traditional approaches. [Copyright &y& Elsevier]

Abstract: In this paper we present an agent-based model of specialization, exchange and inequality within a clustered social network, with implications for the economic effect that contact with colonizing groups may have had on prehistoric indigenous populations. [Copyright &y& Elsevier]

Abstract: A key tool in the study of the dynamics of vector fields near an equilibrium point is the theory of normal forms, invented by Poincaré, which gives simple forms to which a vector field can be reduced close to the equilibrium. In the class of formal vector valued vector fields the problem can be easily solved, whereas in the class of analytic vector fields divergence of the power series giving the normalizing transformation generally occurs. Nevertheless the study of the dynamics in a neighborhood of the origin can very often be carried out via a normalization up to finite order. This paper is devoted to the problem of optimal truncation of normal forms for analytic vector fields in . More precisely we prove that for any vector field in admitting the origin as a fixed point with a semi-simple linearization, the order of the normal form can be optimized so that the remainder is exponentially small. We also give several examples of non-semi-simple linearization for which this result is still true. [Copyright &y& Elsevier]

In the paper we study a semiparametric density estimation method based on the model of an elliptical distribution. The method considered here shows a way to overcome problems arising from the curse of dimensionality. The optimal rate of the uniform strong convergence of the estimator under consideration coincides with the optimal rate for the usual one-dimensional kernel density estimator except in a neighbourhood of the mean. Therefore the optimal rate does not depend on the dimension. Moreover, asymptotic normality of the estimator is proved. [Copyright &y& Elsevier]

In this paper we study the existence and qualitative property of standing wave solutions ψ(x,t)=e-iEt/ℎu(x) for the nonlinear Schrödinger equation iℎ∂ψ/∂t+ℎ2/2mΔψ-W(x)ψ+|ψ|p-1ψ=0 with E being a critical frequency in the sense that infx∈RN W(x)=E. We show that if the zero set of W-E has several isolated connected components Zi(i=1,…,m) such that the interior of Zi is not empty and ∂Zi is smooth, then for ℎ>0 small there exists, for any integer k,1⩽k⩽m, a standing wave solution which is trapped in a neighborhood of ⋃j=1k Aj, where {Aj | j=1,…,k} is any given subset of {Zi | i=1,…,m}. Moreover the amplitude of the standing wave is of the level ℎ2/p-1. This extends the result of Byeon and Wang (Arch. Rational Mech. Anal. 165 (2002) 295) and is in striking contrast with the non-critical frequency case infx∈RN W(x)>E, which has been studied extensively in the past 20 years. [Copyright &y& Elsevier]

This paper uses a newly available data set on African-American and Latina mothers living in an inner-city neighborhood of Chicago to study the role of depression as a potential barrier to economic self-sufficiency. Logit regressions that control for a rich set of background characteristics reveal that a short period of high depressive symptoms does not have major repercussions in the economic sphere. However, repeated episodes or a prolonged condition of high depressive symptoms is strongly associated with an elevated risk of subsequent welfare dependency. [ABSTRACT FROM AUTHOR]

The formation of a social group, such as the group of individuals sharing a territory, depends on the interaction between choices made by individuals to stay or disperse. The process can be modelled as a multi-player variant of the well-known War of Attrition in evolutionary game theory, as shown by Blackwell (1997; J. Theor. Biol.189, 175–181). In this paper, we extend the set of strategies defined there by allowing reappraisal during the game. We give a formal analysis of the evolutionarily stable strategy, where one exists, and illustrate it with an example based on badger (Meles meles) territoriality. The results predict that group size will be well adapted to, and very sensitive to, the precise conditions under which the game is played, and give an indication of the potential for parent–offspring conflict. [Copyright &y& Elsevier]

Animated GIF has become a key communication tool in contemporary social platforms thanks to highly compatible with affective performance, and it is gradually adopted in commercial applications. Therefore, the copyright protection of the animated GIF requires more attention. Digital watermarking is an effective method to embed invisible data into a digital medium that can identify the creator or authorized users. However, few works have been devoted to robust watermarking for the animated GIF. One of the main challenges is that the animated image also contains time frame dimension information compare with still images. This paper proposes a robust blind watermarking framework based 3D convolutional neural networks for the animated GIF image, which achieves watermark image embedding and extraction for the animated GIF. Also, noise simulation is developed in frame-level to ensure robustness for the attack of the temporal dimension in this framework. Furthermore, the invisibility of the watermarked animated image is optimized by adversarial learning. Experimental results provide the effectiveness of the proposed framework and show advantages over existing works. • A novel robust watermarking method for the animated GIF image is proposed. • Employ 3D convolutional neural networks to learn the feature of the animated GIF image at the frame-level. • Design various noise attacks to gain robustness of the animated GIF image watermarking. [ABSTRACT FROM AUTHOR]

The neighborhood effect averaging problem (NEAP) is a major methodological problem that might affect the accuracy of assessments of individual exposure to mobility-dependent environmental factors (e.g., air/noise pollution, green/blue spaces, or healthy food environments). Focusing on outdoor ground-level ozone as a major air pollutant, this paper examines the NEAP in the evaluation of sociodemographic disparities in people's air pollution exposures in Los Angeles using one-day activity-travel diary data of 3790 individuals. It addresses two questions: (1) How does the NEAP affect the evaluation of sociodemographic disparities in people's air pollution exposures? (2) Which social groups with high residence-based exposures do not experience neighborhood effect averaging? The results of our spatial regression models indicate that assessments of sociodemographic disparities in people's outdoor ground-level ozone exposures might be erroneous when people's daily mobility is ignored because of the different manifestations of neighborhood effect averaging for different social/racial groups. The results of our spatial autologistic regression model reveal that non-workers (e.g., the unemployed, homemakers, the retired, and students) do not experience downward averaging : they have significantly lower odds of experiencing downward averaging that could have attenuated their high exposures experienced in their residential neighborhoods while traveling to other neighborhoods (thus, being doubly disadvantaged). Therefore, to avoid erroneous conclusions in environmental inequality research and ineffective public policies, it would be critical to take the NEAP into account in future studies of sociodemographic disparities related to mobility-dependent environmental factors. • Ignoring human mobility may lead to the neighborhood effect averaging problem (NEAP). • This study examined how the NEAP affects assessments of sociodemographic disparities in people's ozone exposures. • We found that these assessments might be erroneous when people's daily mobility is ignored. • Non-workers constitute the doubly disadvantaged groups that do not experience downward averaging. • Studies on exposures to mobility-dependent environmental factors should consider the NEAP. [ABSTRACT FROM AUTHOR]

This paper presents a general alternative interpretation of correlational findings which link perceptual or questionnaire measures 10 data on performance. It is posited that organizational participants possess theories of performance just as do organizational researchers, and that respondents will use knowledge of performance as a cue by which they attribute characteristics to themselves, their work groups, and organizations. According to this attribution hypothesis. self-report data on organizational characteristics may actually represent the consequences rather than the determinants of performance. To test this alternative interpretation of correlational findings, an experiment was conducted in which knowledge of group performance (positive vs negative) was a manipulated independent variable. The results showed that knowledge of performance affected the levels of influence, cohesiveness, communication, motivation, and openness to change attributed by members to their work groups. These findings were also replicated by an interpersonal simulation. The data of the true experiment and the interpersonal simulation, together, provide strong evidence for the attribution hypothesis. [ABSTRACT FROM AUTHOR]

This paper develops a mathematical model of the distribution over time of talking in discussion groups. Researchers of small group processes and social inequality have long recognized that interaction in small discussion groups is usually not equally distributed and that being a person who talks more than others is associated with having higher status outside the group and greater prestige and influence within the group. There is also a history of mathematical approaches to describing this phenomenon. As an addition to this literature, here a nonlinear dynamical system model is presented and used to develop computer simulations that are compared with data from a laboratory study of real four-person discussion groups. The model is based on theoretical assumptions about group processes including individual differences in volubility, status generalization, deference hierarchies and norms of taking turns and of fairness. While none of these alone make predictions that match the data, when they are all combined simulations are produced that closely match the data in both changes over time and differentiation among members. The dynamical system using the parameters as estimated for these data reaches a fixed point, which may help understand how groups structures become stable under some conditions but not others. [ABSTRACT FROM AUTHOR]

• Technological and behavioural developments in Europe at 400,000 years ago. • Model of landscape and resources shaping development of localised material culture. • Model of population movement triggered by shifts in climate or environment. • Estimates of social group and territory size for Middle Pleistocene Europe. Identification of cultural groups is rare in the early Palaeolithic due to site formation processes including taphonomy and the effect of raw material and site function. This paper reviews a critical period in Europe at about 400 ka (MIS 11) when we may be able to identify such groups. This period, sees more sustained occupation and evidence of new technologies, including bone and wooden tools, hunting and fire-use. Importantly, brain size had begun to approach modern capacity. The fine-tuned record from Britain enables correlation of sites and new models of human behaviour to be developed. Millennial-scale changes in material culture can now be recognised, which can be interpreted as brief incursions by different cultural groups into Britain from mainland Europe. We suggest that population movement was primarily driven by changes in climate and environment. We further propose that variation in material culture is a reflection of local resources and landscape and that during stable environment localised expressions of culture emerge. This can be applied to Europe, where it is suggested that a complex mosaic of small-scale cultural groupings can be identified, some with and some without handaxes, but underpinned by a common set of technologies and behaviours. [ABSTRACT FROM AUTHOR]