José Antonio Muñoz-Reyes

Although the Dark Triad (i.e., psychopathy, Machiavellianism, and narcissism) has been consistently linked to aggressive behaviors such as bullying and violence, two important questions about these associations remain unresolved. First, little is known about how they differ between women and men. Second, it remains unclear how factor overlap affects their substantive interpretation. Drawing on evolutionary accounts of intrasexual competition, we predict stronger associations with physical and verbal aggression in men and hostility in women. We test these predictions on Short Dark Triad and Buss and Perry Aggression Questionnaire data from 600 Chilean adults, using bifactor (S−1) structural equation modeling. We find that Machiavellianism predicts all aggression outcomes, psychopathy-specific variance positively predicts physical aggression, and narcissism-specific variance negatively predicts hostility. Sex differences in aggression overlap with sex differences in aversive traits, but none of the Dark Triad-aggression associations consistently differ by sex. By introducing the variance-weighted latent effect (VWLE), we provide the first substantive translation of these bifactor associations. VWLE clarifies how reference facet and trait-specific associations reinforce one another for psychopathy but largely cancel out for narcissism, making the implications of residual coefficients explicit.

Introducción: La otitis externa difusa es una inflamación aguda del conducto auditivo externo, causada principalmente por Pseudomonas aeruginosa y Staphylococcus aureus. La participación de otros bacilos gramnegativos es excepcional y poco documentada. Objetivo: Aportar evidencia mediante la descripción de un caso de otitis externa difusa en el que se aisló Klebsiella oxytoca, bacteria no descrita previamente como agente causal en infecciones óticas humanas, y destacar la relevancia clínica de considerar patógenos inusuales en cuadros de evolución atípica. Metodología: Se presenta el caso de un hombre de 43 años, cuyos antecedentes se resguardaron, con clínica de otitis externa mixta cuyo cultivo evidenció crecimiento de Klebsiella oxytoca y Aspergillus niger. El paciente fue evaluado clínicamente y mediante otomicroscopía, con toma de cultivos y control tras manejo tópico dirigido. Resultado: Paciente evolucionó favorablemente bajo tratamiento antimicótico y antibacteriano tópico. Discusión: Klebsiella oxytoca es un bacilo gramnegativo oportunista, cuyo rol en otitis solo ha sido reportado en modelos animales y en un caso humano de otitis externa maligna en 1992, sin nuevos registros en la literatura desde entonces. En este caso, la disbiosis inducida por clindamicina y la inmunosupresión local por corticoides tópicos favorecieron su aparición. Conclusión: Este reporte documenta una otitis externa difusa asociada a Klebsiella oxytoca y Aspergillus niger, destacando la importancia de considerar patógenos inusuales y de realizar cultivos con antibiograma en casos de evolución atípica, reforzando la necesidad de un enfoque clínico basado en el pensamiento crítico y la reevaluación diagnóstica frente a presentaciones no habituales.

Introduction: The COVID-19 pandemic drastically changed people's lives. It had consequences at the individual and social level. The behavioral immune system predicts that when faced with the risk of contagion from pathogens, people tend to reduce their sociality, especially sociosexuality. We examine this prediction by evaluating decreases in the pandemic of the different dimensions of sociosexuality of young men (i.e., short and long-term mating orientation, sexual desire, and sociosexual behavior) and considering their relationship status (single or paired). Methods and materials: We compared data from two cross-sectional studies carried out in the laboratory with convenience sampling methods in the pre-pandemic period (in the years 2016 and 2018 with a sample size of N = 463) and pandemic (face-to-face panstudy N = 234,data online, N = 182), considering possible differences between samples of the same period. We reached an N = 879 young men who answered a sociodemographic questioarticipants answered a sociodemographic questionnaire that inclnnaire and the Multidimensional Sociosexual Orientation Inventory. To test our predictions, we fitted general linear models. Results: Results point to a significant decrease in long-term mating orientation in paired and single men, but only when compared with the pandemic face-to-face study. In addition, no differences were found for short-term mating orientation. For sociosexual desire (i.e., sexual fantasies), we found a reduction in single pre-pandemic individuals to be compared with the sample of pandemic online study. Finally, we found a decrease in sociosexual behavior (i.e., number of partners in the last year) between pre-pandemic samples and the pandemic itself, regardless of their relationship status and samples inside of each period. In addition, we carry out analyses with a reduced sample to re-test our predictions based on the perception of contagion risk (measured by a survey from OMS). Conclusion: We find changes are maintained at the level of sociosexual desire and sexual behavior but mainly in those individuals with a greater perception of the risk of contagion. The hypotheses derived from the behavioral immune system regarding the decrease in sociosexuality in a context of risk of contagion by pathogens, as was the case in the initial period of COVID-19, are corroborated only in terms of desire and behavior, which suggests a certain stability in attitudes i.e., the menace of contagion modifies proximal aspects of sociosexuality, such as fantasies and behavior, but has no apparent effect on the calibration of the predisposition of individuals to varying levels of commitment in sexual relationships. These findings will allow us to understand better how the dimensions of sociosexuality (i.e., fantasies, attitudes and behavior) are affected when there are contexts of high risk of contagion, such as COVID-19. These findings will allow us to understand better how sociosexuality is affected when there are contexts of high risk of contagion, such as COVID-19.

Objective: There is evidence that suggests that affective dimensions, personality traits, as well as students’ cooperative interpersonal interactions, are an important element in the students learning process. In this work we propose a theoretical model, based on evidence, that shows the direct and indirect relationships between these factors and academic performance in mathematics courses, in undergraduate and school students.Methods: To understand the type of relationships between these variables, the PANAS psychometric test of positive and negative affect, the BIG FIVE personality test and the economic decision game DUPLES GAME were applied. The study sample was 130 students between 17 and 22 years of age from undergraduate and school (M ± SD = 20.1 ± 3.99).Results: From a path analysis, statistically significant relationships were found, for example, a direct relationship between neuroticism and positive affect, which in turn is related to academic performance. We also found a direct relationship between neuroticism and negative affect, extraversion and positive affect. This allows us to propose that some of the independent variables of the model directly and indirectly influence the academic performance of students in the subject of mathematics.Conclusion: Positive affect and negative affect directly affect academic performance in mathematics, neuroticism has a direct impact on negative affect and extraversion direct impact on positive affect. Consequently, there are direct and indirect relationships between personality traits and affective dimensions, which affect the academic performance of mathematics students.

We used the SOI-M Multidimensional Sociosexual Orientation Inventory developed initially by Jackson and Kirkpatrick (2007) for validation in the Chilean population. This 3-dimensional instrument measures sociosexuality in terms of short-term mating orientation, long-term mating orientation and sociosexual behavior. This inventory allows us to capture the deployment of reproductive strategies in men and women simultaneously (that is, in the short and long-term). We tested the instrument's psychometric properties from a final sample of 865 subjects (247 women and 616 men) between 18 and 55 years old (M = 23.56; SD = 5.52). First, with a subsample (N=172), we performed and EFA to establish dimensionality. Then, with the remaining sample (N=693) an ESEM and CFA. We performed an ESEM for confirmatory analysis, analyzed invariance by sex and relations with other variables. We verified the existence of three factors, maintaining the 20 original items. Then, we eliminated the redundant or cross-factor loading items, thus obtaining a reduced version of 15 items and three factors. We tested and verified the convergent and divergent validity of the instrument. Also, we tested invariance by sex, establishing that the SOI-M behaves invariantly. The SOI-M is a valid and reliable instrument to measure multidimensional sociosexuality in the Chilean population.Keywords: sociosexuality, validation, psychometric properties, human mating, strategic pluralism

Intergroup conflict has been a persistent aspect of human societies since the emergence of our species. Various researchers have proposed that competition between groups has acted as a key selective force throughout human evolutionary history. Such intergroup competition for limited resources exacerbated the expression of intergroup aggression and intragroup cooperation. Furthermore, it would have a sexual dimorphism, with men demonstrating increased sensitivity to conflict threats—in order to maximize reproductive opportunities—, while women generally reject from active engagement in intergroup conflict. In the present study, we conducted behavioral experiments under controlled laboratory conditions to measure cooperation and aggression from using virtual games, specifically the Public Good Games and the Point Subtraction Aggression Paradigm, in a sample of 541 participants. We created control and experimental intergroup competition scenarios, where aggression and cooperation were necessary to increase monetary rewards. Our results shows that men modulate aggression and cooperation in the presence of intergroup conflict. In addition, our data also reveals that women cooperate more than men and display heightened levels of cooperation and aggression when confronted with intergroup conflict. These findings prompt a reevaluation of current functional theoretical models concerning the role of women in intergroup conflict and suggest that the dynamics of human aggression and cooperation may be more nuanced than previously believed.

In both sexes, aggression has been described as a critical trait to acquire social status. Still, almost uniquely in men, the link between aggressiveness and the genetic background of testosterone sensitivity measured from the polymorphism in the androgen receptor (AR) gene has been previously investigated. We assessed the relevance of the AR gene to understand aggression and how aggressiveness affects social status in a cross-sectional study of 195 participants, for the first time in both young men and women. We estimated polymorphism sequences from saliva and measured aggression and self-perceived social status. Unfortunately, the results did not support our prediction because we did not find any of the expected relationships. Therefore, the results suggest that the genetic association between aggressive mechanisms and polymorphism of the AR gene is less straightforward than expected, at least in men, and seems to indicate that aggression is not usually used to gain social status in our population.

In our species, the formation and maintenance of romantic partners is a nonrandom process. In this sense, similarity between members of the couple can be relevant for the beginning of the relationship (i.e., assortative mating) and maintenance, being similarity in attractiveness one of the most interesting aspects of this phenomenon. Despite that similarity in attractive traits has been documented, there is a lack of studies including modern morphological measures like fluctuating facial asymmetry or body fat percentage when assessing the effect that similarity in attractiveness could provoke on behaviors and feelings necessary to maintain a long-term relationship (e.g., satisfaction and trust). We assessed the presence of similarity in attractiveness for self-perceived measures (attractiveness and mate value) and physical traits (body fat percentage, body mass index, and fluctuating facial asymmetry) in a population of 196 heterosexual young couples from Chile (n = 392). Then, using actor-partner interdependence models (APIM), we assessed whether satisfaction and trust within the couples were influenced by attractiveness. Our results indicated the presence of similarity for all studied traits with the exception of fluctuating facial asymmetry. In addition, we only found that self-assessment of attractiveness is important for satisfaction in women, and partner's physical attractiveness is important for satisfaction and trust in men. Our results suggest that similarity in attractiveness is not playing a major role in affecting relationship. It is probably that similarity could be better explained from the initial stages of relationship, where the mating market forces conduce to the conformation of similar couples.

Over the past 10 years, Oosterhof and Todorov’s valence–dominance model has emerged as the most prominent account of how people evaluate faces on social dimensions. In this model, two dimensions (valence and dominance) underpin social judgements of faces. Because this model has primarily been developed and tested in Western regions, it is unclear whether these findings apply to other regions. We addressed this question by replicating Oosterhof and Todorov’s methodology across 11 world regions, 41 countries and 11,570 participants. When we used Oosterhof and Todorov’s original analysis strategy, the valence–dominance model generalized across regions. When we used an alternative methodology to allow for correlated dimensions, we observed much less generalization. Collectively, these results suggest that, while the valence–dominance model generalizes very well across regions when dimensions are forced to be orthogonal, regional differences are revealed when we use different extraction methods and correlate and rotate the dimension reduction solution. Protocol registration The stage 1 protocol for this Registered Report was accepted in principle on 5 November 2018. The protocol, as accepted by the journal, can be found at https://doi.org/10.6084/m9.figshare.7611443.v1.

The Male Warrior Hypothesis (MWH) establishes that men’s psychology has been shaped by inter-group competition to acquire and protect reproductive resources. In this context, sex-specific selective pressures would have favored cooperation with the members of one’s group in combination with hostility towards outsiders. We investigate the role of developmental testosterone, as measured indirectly through static markers of prenatal testosterone (2D:4D digit ratio) and pubertal testosterone (body musculature and facial masculinity), on both cooperation and aggressive behavior in the context of intergroup conflict among men. Supporting the MWH, our results show that the intergroup conflict scenario promotes cooperation within group members and aggression toward outgroup members. Regarding the hormonal underpinnings of this phenomenon, we find that body musculature is positively associated with aggression and cooperation, but only for cooperation when context (inter-group competition) is taken into account. Finally, we did not find evidence that the formidability of the group affected individual rates of aggression or cooperation, controlling for individual characteristics.