Childhood environmental harshness predicts coordinated health and reproductive strategies:A cross-sectional study of a nationally representative sample from France

There is considerable variation in health and reproductive behaviours within and across human populations. Drawing on principles from Life History Theory, psychosocial acceleration theory predicts that individuals developing in harsh environments decrease their level of somatic investment and accelerate their reproductive schedule. Although there is consistent empirical support for this general prediction, most studies have focused on a few isolated life history traits and few have investigated the way in which individuals apply life strategies across reproductive and somatic domains to produce coordinated behavioural responses to their environment. In our study, we thus investigate the impact of childhood environmental harshness on both reproductive strategies and somatic investment by applying structural equation modeling (SEM) to cross-sectional survey data obtained in a representative sample of the French population (n = 1015, age: 19 – 87 years old, both genders). This data allowed us to demonstrate that (i) inter-individual variation in somatic investment (e.g. effort in looking after health) and reproductive timing (e.g. age at first birth) can be captured by a latent fast-slow continuum, and (ii) faster strategies along this continuum are predicted by higher childhood harshness. Overall, our results support the existence of a fast-slow continuum and highlight the relevance of the life history approach for understanding variations in reproductive and health related behaviours

INFLUÊNCIA DA DURAÇÃO DA AMAMENTAÇÃO NA INCIDÊNCIA DE CÁRIE DENTÁRIA EM PRÉ-ESCOLARES

Introdução: A cárie é um estrago da estrutura dentária realizado por bactérias que se proliferam na cavidade oral principalmente nos dentes decíduos, onde a estrutura mineralizada é menor em relação aos dentes permanentes. O aleitamento materno é de grande importância para os recém-nascidos, uma vez que os nutrientes do leite são necessários para o bem estar das crianças de colo, que não podem se alimentar de outras fontes. Vale ressaltar, que com a amamentação,  grande parte de doenças deixaram de ocorrer devido a não ingestão de alimentos que podem aumentar o risco de infecções e problemas de saúde. Destaca-se que a amamentação é benéfica tanto para a criança quanto para a mãe em questão nutritiva e a ligação materna. Contudo, houve um aumento significativo de até 3 vezes da cárie nos dentes decíduos. Grandes partes dos pais não se atentam a higiene bucal de seus filhos por serem tão novos e deixam a desejar os mínimos cuidados, podendo gerar danos futuros ao sorriso dos pequenos. Sendo assim, crianças que são alimentadas por mamadeira têm mais cárie dentária na dentição decídua do que crianças amamentadas pelo leite materno. Com isso, foi visto que a amamentação é mais eficaz na prevenção da cárie dentária na primeira infância do que na alimentação pela mamadeira. Objetivo: Relatar as possíveis complicações de cariogenicidade em recém-nascidos e crianças de até 6 meses que nutrem-se de leite materno. Metodologia: Foi feita uma pesquisa bibliográfica integrativa nas bases de dados: Scielo, Biblioteca Virtual de Saúde e Pubmed, com as palavras chave: “cárie”, “odontologia” e “amamentação” sem restrição de ano de publicação. Considerações: A cariogenicidade em bebês é muito comum devido à pouca movimentação da língua para a auto limpeza, garantindo uma área de proliferação da cárie no substrato (leite) devido ao tempo de duração que o leite fica na boca da criança diferindo de um adulto, que tem movimentos concretos tanto da língua quanto dos músculos. Com a amamentação, o número de incidências e cárie aumentou nos últimos anos e consequentemente mais jovens e adultos precisam de tratamento odontológico. Sendo assim, o aleitamento materno é mais eficaz que o leite dado da mamadeira, pois o mesmo pode conter bactérias, provocando cáries na dentição decídua

Stratégies fast-slow dans les populations humaines : appliquer les principes de la théorie des traits d'histoire de vie pour expliquer la variation interindividuelle

Social gradients in behavior have been documented across various domains of people’s lives. In western countries, low SES individuals tend for instance to invest less in their education, to smoke more, are more subject to overweight and are more willing to take risks in financial settings. Being exposed to deprivation therefore seems to elicit a constellation of behaviors that appear to covary in a systematic fashion. This behavioral constellation of deprivation has been mostly interpreted as the product of poor decision making abilities, of a general failure of willpower. In this dissertation we explore a different interpretation that is rooted in adaptive explanations of human behavior. Instead of viewing the behaviors of low SES individuals as suboptimal deviations from a global optimum, they are seen as adjustments of people’s overall life strategies that are, from an evolutionary point of view, adaptive in the particular context of a deprived ecology. Indeed, we will explore the idea that deprived environments select for strategies that put more weight on present outcomes over uncertain future outcomes, and that this present orientation in low SES individuals propagates across a range of decision domains, giving rise to the constellation. To this aim, we first use structural equation models on observational data from a diversity of samples, to analyze the covariation between peoples’ behaviors in several relevant domains (health, reproduction, social trust) and their exposure to deprivation during childhood and/or adulthood. Overall, we find that a lower somatic effort tends to covary with a more short-term reproductive strategy, as well as lower social trust. This pattern is associated with a higher exposure to deprivation, with unique effects of early life conditions. In addition to this empirical work, we further investigate the theoretical underpinnings of our working hypotheses, from an adaptationist perspective. Specifically, we build a formal life history model to predict optimal changes in discounting within and between individuals. This allows us to highlight that the extent to which individuals prefer short-term rewards, should vary depending on two main parameters: 1) the uncertainty around their ability to actually collect delayed rewards, and 2) the opportunity costs of not having the reward during the delay. Finally, we conclude by discussing the promising perspective of further integrating the approach adopted in the present thesis, with more traditional social and behavioural sciences.Des gradients sociaux ont été documentés pour une variété de comportements individuels. Au sein des pays occidentaux par exemple, les personnes ayant un statut socio-économique plus bas ont tendance à investir moins dans leur éducation, à fumer davantage, sont plus susceptibles de souffrir d'obésité et plus enclines à prendre des risques dans des contextes économiques. Ainsi, être exposé à des conditions de vie précaire semble engendrer une série de comportements, covariant de manière systématique. Ce syndrome comportemental a été principalement interprété comme le produit de déficits cognitifs ayant traits à la prise de décision et/ou à un manque de volonté. Dans ce manuscrit, nous explorons une approche différente, qui s'ancre dans les explications adaptationnistes des comportements humains. Au lieu d'appréhender les comportements observés chez les individus en situation de précarité comme des anomalies, ceux-ci sont perçus comme des ajustements des stratégies individuelles d'histoire de vie, adaptés à la vie dans des environnements précaires. En effet, nous approfondirons l'hypothèse selon laquelle un environnement précaire sélectionne des stratégies qui accordent davantage de poids aux bénéfices immédiats plutôt qu’aux investissements de long terme, affectant dès lors toute une gamme de comportements. Dans un premier temps, nous analyserons par le biais de modèles d'équations structurelles, différents jeux de données afin de mesurer le degré de covariation de comportements ayant trait à la reproduction, à l'investissement dans la santé et au niveau de confiance, ainsi que leur association éventuelle avec le niveau de précarité éprouvé pendant l'enfance ou à l'âge adulte. Globalement, nos résultats indiquent qu'une réduction de l’investissement dans la santé co-varie avec une stratégie de reproduction plus court-termiste, ainsi qu'un plus faible niveau de confiance. De plus, ce pattern est surreprésenté chez les personnes en situation de précarité, avec des effets persistants des conditions pendant l'enfance. En parallèle de ces travaux empiriques, nous nous sommes par ailleurs intéressés aux fondements théoriques de nos hypothèses de travail. Précisément, nous avons développé un modèle formel de stratégie d'histoire de vie prédisant les changements de préférences temporelles intra- et interindividuelles. Celui-ci nous a permis de mettre en évidence l’importance de deux facteurs distincts pour déterminer le degré optimal avec lequel des individus doivent préférer les récompenses de court-terme : 1) le niveau d'incertitude sur la probabilité de collecter une récompense délayée dans le temps, et 2) le coût d'opportunité à ne pas bénéficier de la récompense pendant la période de délai. Enfin, nous concluons ce travail en discutant des perspectives particulièrement intéressantes offertes par une intégration plus poussée de l'approche développée dans cette thèse, avec d'autres sciences sociales et sciences du comportement plus traditionnelles

Time is money. Waiting costs explain why selection favors steeper time discounting in deprived environments.

International audienceIndividuals exposed to deprivation tend to show a characteristic behavioural syndrome suggestive of a short time horizon. This pattern has traditionally been attributed to the intrinsically higher unpredictability of deprived environments, which renders waiting for long term rewards more risky (i.e. collection risks are high). In the current paper, based on a simple dynamic life history model, we show that a significant portion of individuals' propensity to discount future rewards might have a completely distinct origin. Upon collecting a resource, individuals have the opportunity to accumulate "capital" (e.g. grow muscular tissue, build a protective shelter, buy a car, etc.), which eventually increases their productivity and/or their chances of survival. As a result, delaying the collection of a resource creates an opportunity cost in the sense that during the waiting time, the benefits otherwise generated by the increment in capital are lost. These forgone benefits are independent of collection risks and constitute waiting costs per se. Using optimal control theory we show that these costs can lead to the evolution of short time horizons even in the complete absence of collection risks. Moreover, assuming diminishing returns to capital, we show that the evolutionarily stable time horizon increases with the amount of capital already owned by individuals. When individuals possess little capital, they have a lot of room to improve their productivity and/or survival, hence they should be impatient to collect resources; that is, their time horizon should be short. On the contrary, when individuals already possess a lot of capital, the benefits of further accumulation are plateauing, hence patience becomes a more profitable strategy and individuals should lengthen their time horizon. This means that individuals get more patient as they age and that people in deprivation, who still have important productive and survival needs that can be satisfied, should have a shorter time horizon. Moreover, beyond time horizon, our model shows that people with little capital should also be more risk averse than the more privileged. Taken together, these results lead us to interpret the behavioral constellation of deprivation in a new way

Both collection risk and waiting costs give rise to the behavioral constellation of deprivation

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Climate is not a good candidate to account for variations in aggression and violence across space and time

International audienceWe agree with Van Lange et al. that climate is likely to affect individuals' social behavior in many ways. However, we suspect that its impact on physiology and psychology is so remote that its predictive power disintegrates almost completely through the causal chain underlying aggression and violence

Predictive modeling of religiosity, prosociality, and moralizing in 295,000 individuals from European and non-European populations

International audienceAbstract Why do moral religions exist? An influential psychological explanation is that religious beliefs in supernatural punishment is cultural group adaptation enhancing prosocial attitudes and thereby large-scale cooperation. An alternative explanation is that religiosity is an individual strategy that results from high level of mistrust and the need for individuals to control others’ behaviors through moralizing. Existing evidence is mixed but most works are limited by sample size and generalizability issues. The present study overcomes these limitations by applying k -fold cross-validation on multivariate modeling of data from >295,000 individuals in 108 countries of the World Values Surveys and the European Value Study. First, this methodology reveals no evidence that European and non-European religious people invest more in collective actions and are more trustful of unrelated conspecifics. Instead, the individuals’ level of religiosity is found to be weakly but positively associated with social mistrust and negatively associated with the production of behaviors, which benefit unrelated members of the large-scale community. Second, our models show that individual variation in religiosity is well explained by the interaction of increased levels of social mistrust and increased needs to moralize other people’s sexual behaviors. Finally, stratified k -fold cross-validation demonstrates that the structures of these association patterns are robust to sampling variability and reliable enough to generalize to out-of-sample data

An Improvisational Approach to Acquire Social Interactions

To build agents that can engage users in more open-ended social contexts, research has increasingly been focused on data-driven approaches to reduce the requirement of extensive, hand-authored behavioral content creation. However, one fundamental challenge of data-driven approaches is acquiring the interaction data with sufficient variety that reflects the characteristics of open-ended social interactions. Previous work attempts to acquire social interaction data either from face-to-face interactions or human-agent interactions using a simulated environment. In this work, Active Analysis (AA), a theater rehearsal technique, was applied to collect diverse social strategies and interactions. In particular, this work integrated AA into a web-based crowdsourcing task that requires two crowd workers to conduct a bilateral multi-level multi-issue negotiation. Findings from a between-subject experiment with 200 crowd workers recruited from Amazon Mechanical Turk demonstrated that AA could facilitate the creativity of crowd workers and thus lead to social interaction data with greater variety. In addition, AA provides a means to control the diversity so that the coverage of the collected data is consistent with the goals of the application. The results presented in the paper lay a good foundation for future work on data-driven approaches to build socially interactive agents

Predictive multivariate modelling of religiosity, prosociality and moralizing in 295,000 individuals from European and non-European populations

Why do moral religions exist? An influential explanation is that religious beliefs in supernatural punishment is cultural group adaptation enhancing prosocial attitudes and thereby large-scale cooperation. An alternative explanation is that religiosity is an individual strategy that results from high level of mistrust and the need for individuals to control others’ behaviours through moralizing. Existing evidence is mixed but most works are limited by sample size and generalizability issues. The present study overcomes these limitations by applying k-fold cross-validation on multivariate modelling of data from more than 295,000 individuals in 108 countries of the World Values Surveys and the European Value Study. This methodology demonstrates that in European as well as in non-European samples, religious people invest less in collective actions and are more mistrustful of others. By contrast, we find a strong and positive association between higher level of mistrust, higher level of moralizing and higher level of religiosity