“Driving While Black”: A Theory for Interethnic Integration and Evolution of Prejudice

This paper studies the evolution of interethnic attitudes, the integration or segregation dynamics of ethnic minorities and the conditions for the rising of ethnic-based social hierarchies. By means of a cultural evolution framework, a dynamics of interethnic attitudes is provided and conditions for their convergence derived. Steady states implying a constant role of racism and no role for racism are identified. Deriving sufficient conditions for convergence, we find that the way in which Oblique Socialization Schemes (the way children react to out-of-family stimuli when forming their cultural values) are defined and modelled becomes crucial for the structure of the derived long run equilibria. In particular, we find that Steady States implying an Ethnic-based social ranking or full integration of ethnicities may be reached depending on whether or not agents use Reciprocity and/or Ethnocentrism in their interethnic attitudes formation schemes. Allowing different groups for asymmetric use of reciprocity and Ethnocentrism, we explain why different ethnic minorities may show different integration patterns, and what are the different roles (Cultural bridge, cultural hub) an ethnic group may play in the integration process. Moreover, in this way, we explain why attitudes of some groups towards others converge to the same values, while other groups seems to be excluded from this process. At last, we provide the first steps for the endogeneization of socialization structures.Cultural transmission, Minority integration, Evolution of preferences

Understanding Cultural Traits: A Multidisciplinary Perspective on Cultural Diversity

UNESCO Universal Declaration on Cultural Diversity (2 November 2001) defines culture with an emphasis on cultural features: “culture should be regarded as the set of distinctive spiritual, material, intellectual and emotional features of society or a social group”, encompassing, “in addition to art and literature, lifestyles, ways of living together, value systems, traditions and beliefs”. Cultural traits are also the primitive of mathematical models of cultural transmission inspired by population genetics, imported and refined by economics. Any serious evaluation of the notion of “cultural trait”, however, requires the interrogation of many disciplines, from cultural anthropology to linguistics, from psychology to archaeology to musicology. The very possibility of assuming the existence of cultural traits is not granted. In order to start a wide interdisciplinary confrontation, we need a sufficiently loose definition of a cultural trait as any trait whose production in individuals depends, to some extent, on social learning; and we need a deflationary interpretive horizon where cultural traits are not expected to provide an exhaustive theory of culture and cultural change. But from there, we can go a long way if each of the involved disciplines enters the debate with a self-presenting attitude, emphasizing its own methodological practices, and explaining whether and how cultural traits have a role in its own research programs and epistemic goals. Are there differences in aspects of culture that are studied by different disciplines? What definitions of cultural traits are on the table? How do we delimit a trait? How is the problem declined at different observational scales, and which scales are most in focus? Do traits travel in geographical space, and how? Are there other relevant spaces? How are traits modified in their diffusion? Is it possible and useful to build models of this diffusion? Only a strong multidisciplinary perspective can help to clarify these problems about cultural traits, by means of which we understand our precious heritage, cultural diversity

Learning and Selfconfirming Equilibria in Network Games

Consider a set of agents who play a network game repeatedly. Agents may not know the network. They may even be unaware that they are interacting with other agents in a network. Possibly, they just understand that their payoffs depend on an unknown state that in reality is an aggregate of the actions of their neighbors. Each time, every agent chooses an action that maximizes her subjective expected payoff and then updates her beliefs according to what she observes. In particular, we assume that each agent only observes her realized payoff. A steady state of such dynamic is a selfconfirming equilibrium given the assumed feedback. We characterize the structure of the set of selfconfirming equilibria in network games and we relate selfconfirming and Nash equilibria. Thus, we provide conditions on the network under which the Nash equilibrium concept has a learning foundation, despite the fact that agents may have incomplete information. In particular, we show that the choice of being active or inactive in a network is crucial to determine whether agents can make correct inferences about the payoff state and hence play the best reply to the truth in a selfconfirming equilibrium. We also study learning dynamics and show how agents can get stuck in non--Nash selfconfirming equilibria. In such dynamics, the set of inactive agents can only increase in time, because once an agent finds it optimal to be inactive, she gets no feedback about the payoff state, hence she does not change her beliefs and remains inactive

Секвенційні числення композиційно-номінативних модальних логік функціонально-екваційного рівня

Досліджуються композиційно-номінативні модальні та темпоральні логіки функціонально-екваційного рівня. На основі властивостей відношення логічного наслідку для множин формул збудовані числення секвенційного типу для загальних та темпоральних композиційно-номінативних модальних логік такого рівня. Для побудованих числень доведені теореми коректності та повноти

The transmission of continuous cultural traits in endogenous social networks

Hellmann T, Panebianco F. The transmission of continuous cultural traits in endogenous social networks. Center for Mathematical Economics Working Papers. Vol 579. Bielefeld: Center for Mathematical Economics; 2018.We study a model of transmission of continuous cultural traits across generations where children learn their cultural trait from their parents and their social environment modeled by a network. Parents can engage in the socialization process of their children by biasing links in the network in order for their children to adopt a cultural trait similar to their own. In this endogenous network, we study the emergence of positive and negative role models, the existence of a steady state cultural trait, its characterization in terms long-run influence of each dynasty, and the speed of convergence

Civility vs. incivility in online social interactions: an evolutionary approach

Evidence is growing that forms of incivility–e.g. aggressive and disrespectful behaviors, harassment, hate speech and outrageous claims–are spreading in the population of social networking sites’ (SNS) users. Online social networks such as Facebook allow users to regularly interact with known and unknown others, who can behave either politely or rudely. This leads individuals not only to learn and adopt successful strategies for using the site, but also to condition their own behavior on that of others. Using a mean field approach, we define anevolutionary game framework to analyse the dynamics of civil and uncivil ways of interaction in online social networks and their consequences for collective welfare. Agents can choose to interact with others–politely or rudely–in SNS, or to opt out from online social networks to protect themselves from incivility. We find that, when the initial share of the population of polite users reaches a critical level, civility becomes generalized if its payoff increases more than that of incivility with the spreading of politeness in online interactions. Otherwise, the spreading of self-protective behaviors to cope with online incivility can lead the economyto non-socially optimal stationary state

Peer effects and local congestion in networks

We study linear quadratic games played on a network. Agents face peer effects with distance-one neighbors, and strategic substitution with distance-two neighbors (local congestion). For this class of games, we show that an interior equilibrium exists both in the high and in the low regions of the largest eigenvalue, but may not exist in the intermediate region. In the low region, equilibrium is proportional to a weighted version of Bonacich centrality, where weights are themselves centrality measures for the network. Local congestion has the effect of decreasing equilibrium behavior, potentially affecting the ranking of equilibrium actions. When strategic interaction extends beyond distance-two, equilibrium is characterized by a â\u80\u9cnestedâ\u80\u9d Bonacich centrality measure, and existence properties depend on the sign of strategic interaction at the furthest distance. We support the assumption of local congestion by presenting empirical evidence from a secondary school Dutch dataset

Counteracting gemcitabine+nab-paclitaxel induced dysbiosis in KRAS wild type and KRASG12D mutated pancreatic cancer in vivo model

Pancreatic cancer (PC) has a very low survival rate mainly due to late diagnosis and refractoriness to therapies. The latter also cause adverse effects negatively affecting the patients' quality of life, often requiring dose reduction or discontinuation of scheduled treatments, compromising the chances of cure. We explored the effects of a specific probiotic blend on PC mice xenografted with KRAS wild-type or KRASG12D mutated cell lines alone or together with gemcitabine+nab-paclitaxel treatment to then assess tumor volume and clinical pathological variables. Beside a semi-quantitative histopathological evaluation of murine tumor and large intestine samples, histochemical and immunohistochemical analyses were carried out to evaluate collagen deposition, proliferation index Ki67, immunological microenvironment tumor-associated, DNA damage markers and also mucin production. Blood cellular and biochemical parameters and serum metabolomics were further analyzed. 16S sequencing was performed to analyze the composition of fecal microbiota. Gemcitabine+nab-paclitaxel treatment impaired gut microbial profile in KRAS wild-type and KRASG12D mice. Counteracting gemcitabine+nab-paclitaxel- induced dysbiosis through the administration of probiotics ameliorated chemotherapy side effects and decreased cancer-associated stromatogenesis. Milder intestinal damage and improved blood count were also observed upon probiotics treatment as well as a positive effect on fecal microbiota, yielding an increase in species richness and in short chain fatty acids producing- bacteria. Mice' serum metabolomic profiles revealed significant drops in many amino acids upon probiotics administration in KRAS wild-type mice while in animals transplanted with PANC-1 KRASG12D mutated all treated groups showed a sharp decline in serum levels of bile acids with respect to control mice. These results suggest that counteracting gemcitabine+nab-paclitaxel-induced dysbiosis ameliorates chemotherapy side effects by restoring a favorable microbiota composition. Relieving adverse effects of the chemotherapy through microbiota manipulation could be a desirable strategy in order to improve pancreatic cancer patients' quality of life and to increase the chance of cure

Teaching by example and induced beliefs in a model of cultural transmission

We augment standard models of cultural transmission with an explicit account of social learning, grounded in the information transmission literature. Youngsters observe the behavioral trait of a role model and form beliefs about the desirability of that trait. Adults have better information about each trait and have a paternalistic attitude toward their children. This makes them reluctant to adopt myopic behavior to avoid setting a negative example to their children. This signaling distortion increases in the influence parents have over their offspring. We extend the model to allow parental influence to depend on the population frequency of each trait and show that cultural complementarity does not imply convergence to a homogeneous population. We find empirical support for a positive relationship between parental influence and propensity to exert self-restraint by looking at alcohol and tobacco consumption