Publicaciones

Juan David Leongómez, Jan Havlíček, S. Craig Roberts (2022)

Resumen:
Studies show that specific vocal modulations, akin to those of infant-directed speech and perhaps music, play a role in communicating intentions and mental states during human social interaction. Based on this, we propose a model for the evolution of musicality –the capacity to process musical information– in relation to human vocal communication. We suggest that a complex social environment, with strong social bonds, promoted the appearance of musicality-related abilities. These social bonds were not limited to those between offspring and mothers or other carers, although these may have been especially influential in view of altriciality of human infants. The model can be further tested in other species by comparing levels of sociality and complexity of vocal communication. By integrating several theories, our model presents a radically different view of musicality, not limited to specifically musical scenarios, but one in which this capacity originally evolved to aid parent-infant communication and bonding, and even today plays a role, not only in music but also in infant-directed speech (IDS), as well as some adult-directed speech (ADS) contexts.

Christopher D. Watkins, Jeanne Bovet, Ana Maria Fernandez, Juan David Leongómez, Agnieszka Żelaźniewicz, Marco Antônio Corrêa Varella, Danielle Wagstaff (2022)

Resumen:
Feeling and expressing love is at the core of romantic relationships, but individuals differ in their proclivity to worry about their relationships and/or avoid intimacy. Saying ‘I love you’ signals a commitment to a future with our romantic partner. Contrary to gender stereotypes, research in the US demonstrates that men are more likely to confess love first. We aimed to replicate this sex difference in an online cross-national sample (seven countries, three continents), while testing for variation according to attachment style and environment (the national sex ratio). Men were more likely to confess love first in a relationship, with preliminary evidence that this was more likely when men had more choice (more female biased sex ratio). Independent of biological sex, highly avoidant respondents were less happy to hear ‘I love you’ than less avoidant respondents, and highly anxious respondents were happier to hear ‘I love you’ than less anxious respondents. Our findings suggest that prior observations generalize beyond an ethnically homogenous sample, and incorporate attachment theory into the study of love confessions. Our research suggests a dissociation between initial declarations of love (moderated by biological sex) and emotional responses to love confessions, moderated by attachment style but not by biological sex. Key words: Close relationships, Sex differences, Speech acts, Sex ratio, Attachment, Affectionate communication, Error Management Theory.

Hernando Santamaría-García, Miguel Burgaleta, Agustina Legaz, Daniel Flichtentrei, Mateo Córdoba-Delgado, Juliana Molina-Paredes, Juliana Linares-Puerta, Juan Montealegre-Gómez, Sandra Castelblanco, Michael Schulte, Juan David Páramo, Izara Mondragon, Juan David Leongómez, Paula Salamone, Juan González-Pacheco, Sandra Báez, Harris Eyre & Agustín Ibanez (2022)

Resumen:
The SARS-CoV-2 pandemic has imposed widespread negative impacts (economically, psychologically, neurologically, and societally), and has changed daily behaviors on a global scale. Such impacts are more significant and pervasive in countries with higher levels of inequality and reduced Government capacity and responsiveness, such as those in the Global South (e.g., Colombia). Differences in social and moral cognitive skills may significantly impact individual attitudes and responses to the pandemic. Here, we aimed to assess the extent to which factors associated with prosociality (including empathy, theory of mind (ToM), and moral judgments) predict the perception of SARS-CoV-2 impacts and responses. Participants (N = 413) from Colombia answered factors associated with prosociality measures and judgments about SARS-CoV-2 risk, impact, and acceptance of quarantine guidelines. Results revealed that affective empathy (personal distress and empathic concern) and moral tendencies (deontological trends) predicted greater acceptance of quarantine but in turn yielded an increased perception of risks and individual impacts of SARS-CoV-2. Moreover, age (older) and gender (female) also increased the risk perception and impact estimation. These results underscore the role of prosocial-related predispositions informing individual responses to the pandemic and provide an opportunity to exploit this knowledge to inform successful interventions favoring behavioral change.

Milena Vásquez-Amézquita, Alicia Salvador, Juan David Leongómez (2022)

Resumen:
One research line in criminal behavior studies 2D:4D ratio as predictor of aggression and violent behavior has been established, given that there are sexually dimorphic behaviors associated with the influence of testosterone on brain organization. However, results have been mixed. The aim of this study was to explore the differences in the 2D:4D ratio among offending and non-offending Colombian men in four groups (N = 139). A comparative study was conducted with three groups of offenders sentenced in a Colombian penitentiary: (1) sexual offenders against children (n = 34), (2) sexual offenders against adult women (n = 31), and (3) non-sexual violent offenders (n = 26); as well as one group (4) men with no criminal record (n = 48). The 2D:4D ratio was measured using the hand scanning technique and three digital measurements were analyzed with the Autometric software: right hand ratio, left hand ratio, and difference between the right and left hand ratios (Dr - Iz). Although, in all groups, right-digit ratio was lower that left-digit ratio (negative Dr–l ratio) and, in non-offending men this difference was not significant, no strong significant differences were found between groups in any measure of 2D:4D ratio used (right hand, left hand or Dr−l). The results support the idea that these associations are too weak to consider them predictors of sexual or non-sexual criminal behavior. The risk factors determining sexual or non-sexual criminal behavior, seems to go beyond intra-uterine effects and involve complex interactions between heritability, epigenetics, and pre-natal and post-natal life events.

Karel Kleisner, Petr Tureček, S. Craig Roberts, Jan Havliček, Jaroslava Varella Valentova, Robert Mbe Akoko, Juan David Leongómez, Silviu Apostol, Marco A. C. Varella, S. Adil Saribay (2021)

Resumen:
Sexual selection, including mate choice and intrasexual competition, is responsible for the evolution of some of the most elaborated and sexually dimorphic traits in animals. Although there is clear sexual dimorphism in the shape of human faces, it is not clear whether this is similarly due to mate choice, or whether mate choice affects only part of the facial shape difference between men and women. Here we explore these questions by investigating patterns of both facial shape and facial preference across a diverse set of human populations. We find evidence that human populations vary substantially and unexpectedly in both the range and pattern of facial sexually dimorphic traits. In particular, European and South American populations display larger levels of facial sexual dimorphism than African populations. Neither cross-cultural differences in facial shape variation, differences in body height between sexes, nor differing preferences for facial sex-typicality across countries, explain the observed patterns of facial dimorphism. Altogether, the association between morphological sex-typicality and attractiveness is moderate for women and weak (or absent) for men. Analysis that distinguishes between allometric and non-allometric components reveals that non-allometric sex-typicality is preferred in women’s faces but not in faces of men. This might be due to different regimes of ongoing sexual selection acting on men, such as stronger intersexual selection for body height and more intense intrasexual physical competition, compared with women.

Benedict C. Jones, Lisa M. DeBruine, Jessica K. Flake, ... Juan David Leongómez, Oscar R. Sánchez, Eugenio Valderrama, Milena Vásquez-Amézquita, ... Christopher R. Chartier, & Nicholas A. Coles (2021)

Resumen:
Over the last ten 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 judgments of faces. To which world regions this model applies is a critical, yet unanswered, question. We will address this question by replicating Oosterhof and Todorov’s methodology across multiple world regions.

Vojtěch Fiala, Vít Třebický, Juan David Leongómez, Petr Tureček, Farid Pazhoohi, Selahattin Saribay, Robert Mbe Akoko, Karel Kleisner (2021)

Resumen:
It has been hypothesised that the strength of association between sex typicality and attractiveness follows an adaptive pattern across cultures. Such pattern allows for adjustment of individual preferences for facial cues associated with direct (parenting) and indirect (biological quality) benefits from mating with a potential mate according to environmental conditions. To test this hypothesis, we examined associations among intra-culturally perceived sex typicality, attractiveness, measured skin lightness, measured averageness, and sexual dimorphism of shape from facial images, while controlling for age, body mass, and facial width, in five distinct cultures with different environmental and socioeconomic conditions (Cameroon, N of facial stimuli = 200, 100 women; Colombia, N = 138, 66 women; Czechia, N = 100, 50 women; Iran, N = 87, 43 women; and Turkey, N = 185, 93 women). Our results suggest that measured sexual shape dimorphism and averageness are not significantly associated with neither perceived sex typicality nor attractiveness across the cultures. In all samples of female faces, however, perceived sex typicality was positively related to facial attractiveness. Women found perceived sex typicality in men as more attractive only in the Czech environment, with its relatively abundant resources, and in Colombia, which is a highly socioeconomically heterogeneous and competitive culture. Lighter skin raised the ratings of both attractiveness and sex typicality only in Cameroonian women. Darker men were perceived significantly more sex-typical but not more attractive in Cameroonian, Colombian, and Iranian samples. Altogether, our results highlight the need to control for which measure of sexual dimorphism is used (perceived or measured) and make a detailed description of the local environment. It is the perceived, rather than measured, sexual dimorphism that is associated with perceived attractiveness, and wealth distribution, rather than public, health that seems to affect masculinity preferences.

Juan David Leongómez, Oscar R. Sánchez, Milena Vásquez-Amézquita, Eugenio Valderrama, Andrés Castellanos-Chacón, Lina Morales-Sánchez, Javier Nieto, Isaac González-Santoyo (2020)

Resumen:

Body height is a life-history component. It involves important costs for its expression and maintenance, which may originate trade-offs on other costly components such as reproduction or immunity. Although previous evidence has supported the idea that human height could be a sexually selected trait, the explanatory mechanisms that underlie this selection are poorly understood. Despite extensive studies on the association between height and attractiveness, the role of immunity in linking this relation is scarcely studied, particularly in non-Western populations. Here, we tested whether human height is related to health measured by self-perception, and relevant nutritional and health anthropometric indicators in three Latin-American populations that widely differ in socioeconomic and ecological conditions: two urbanised populations from Bogota (Colombia) and Mexico City (Mexico), and one isolated indigenous population (Me’Phaa, Mexico). Results showed that self-reported health is best predicted by an interaction between height and waist circumference: the presumed benefits of being taller are waist-dependent, and affect taller people more than shorter individuals. If health and genetic quality cues play an important role in human mate-choice, and height and waist interact to signal health, its evolutionary consequences, including cognitive and behavioural effects, should be addressed in future research.

Mauricio Bonilla, Juan David Leongómez (2019)

Resumen:
En este estudio se pretendió corroborar el efecto de inversión con estímulos de rostros calmos, de miedo e ira tomados de la base de datos de rostros calmos y emocionales NSTIM (base de datos de rostros), presentados de forma vertical e invertida, con una duración de presentación de 2000 milisegundos. Los resultados muestran que no hubo modulación del componente N170 tanto en latencia como en amplitud ante la presentación de rostros invertidos comparados con los rostros presentados verticalmente. Tampoco se encontró alteración en la precisión de la respuesta y demora en los tiempos de reacción ante los rostros invertidos comparados con los rostros verticales. Estos resultados probablemente se pueden explicar por la presentación prolongada de los rostros invertidos que permitieron a los participantes tener el tiempo para reorganizar los elementos que componen los rostros. El aporte de este estudio es poner en evidencia que el tiempo de presentación de rostros invertidos es crucial para que se presente el efecto de inversión de rostros, el cual debe estar entre 200 y 500 milisegundos.

Christopher D Watkins, Juan David Leongómez, Jeanne Bovet, Agnieszka Żelaźniewicz, Max Korbmacher, Marco Antônio Corrêa Varella, Ana Maria Fernandez, Danielle Wagstaff, Samuela Bolgan (2019)

Resumen:
Romantic mouth-to-mouth kissing is culturally widespread, although not a human universal, and may play a functional role in assessing partner health and maintaining long-term pair bonds. Use and appreciation of kissing may therefore vary according to whether the environment places a premium on good health and partner investment. Here, we test for cultural variation (13 countries from six continents) in these behaviours/attitudes according to national health (historical pathogen prevalence) and both absolute (GDP) and relative wealth (GINI). Our data reveal that kissing is valued more in established relationships than it is valued during courtship. Also, consistent with the pair bonding hypothesis of the function of romantic kissing, relative poverty (income inequality) predicts frequency of kissing across romantic relationships. When aggregated, the predicted relationship between income inequality and kissing frequency (r=.67, BCa 95%CI[.32,.89]) was over five times the size of the null correlations between income inequality and frequency of hugging/cuddling and sex. As social complexity requires monitoring resource competition among large groups and predicts kissing prevalence in remote societies, this gesture may be important in the maintenance of long-term pair bonds in specific environments.

Milena Vásquez-Amézquita, Juan David Leongómez, Michael C. Seto, Mauricio Bonilla, Alexa Rodríguez-Padilla, Alicia Salvador (2019)

Resumen:

Visual attention patterns measured with eye-tracking techniques provide indirect clues about sexual response. This study aimed to test the category specificity of sexual responses to stimuli varying in gender and age by evaluating both early and late attention of gynephilic and androphilic men and women. We simultaneously presented sexually preferred and nonpreferred stimuli and measured time to first fixation and total duration of fixation on four areas of interest: entire body, then face, chest, and pelvis. Androphilic women’s early attention patterns were nonspecific,whereas gynephilic women and both groups of men showed a category-specific pattern for the entire body. In contrast, all groups showed gender-specific patterns of late attention for all areas of interest. We also found support for age specificity of early and late visual attention in all four groups, with greater attention to adult than child stimuli. This study supports the usefulness of a competing stimulus eye-tracking paradigm as a method to examine gender specificity in gynephilic women and androphilic and gynephilic men, and as a measure of age specificity in gynephilic and androphilic men and women.

Milena Vásquez-Amézquita, Juan David Leongómez, Michael C. Seto, Alicia Salvador (2019)

Resumen:
Men, whether gynephilic or androphilic, show both early and late attention toward adults and not toward children. We examined early and late visual attention to sexually mature versus immature stimuli in four groups of heterosexual men: sexual offenders against children (SOAC = 18), sexual offenders against adults (SOAA = 16), nonsexual offenders (NSO = 18), and nonoffending men (NOM = 19). We simultaneously presented adult and child stimuli and measured time to first fixation, number of first fixations, total duration of fixation, and fixation count to four areas of interest: entire body, then face, chest, and pelvis. We found a significant interaction where only SOAC tended to fixate more first times to child than to adult stimuli. Conversely, we found longer total duration of fixations for the bodies of adults compared to the bodies of children in all groups; however, in both the total duration of fixations and the fixation count for the whole body, but especially in the chest, SOAC tended to fixate longer and more often on child stimuli than the other two groups of offenders, but not longer or more often than NOM. This study adds to the limited research using eye-tracking techniques in samples of SOAC.

Dariusz P. Danel, Jaroslava Varella Valentova, Oscar R. Sánchez, Juan David Leongómez, Marco A. C. Varella, Karel Kleisner (2018)

Resumen:
Objectives: Facial averageness and sexual dimorphism are extensively studied attractiveness markers, which are viewed as possible indicators of biological quality. Both are complex morphological traits and both can be easily assessed from frontal and lateral projection of a human face. Interestingly, examination of mutual relations between the frontal and lateral dimensions of these markers has so far received little attention in published research. Methods: In our cross-cultural study, we used geometric morphometric data from male and female faces from Brazil, Cameroon, Colombia, and the Czech Republic, and analysed correlations between frontal and lateral measurements of averageness and degree of maleness/femaleness, i.e. individual variation in features that characterize sexual dimorphism. We also analysed whether the association between frontal and lateral measurements differs in men and women. Results: In general, our results showed a moderate correlation in sexually dimorphic features between lateral and frontal facial configuration in both sexes, while frontal and lateral facial averageness was moderately correlated only in women. This pattern was less consistent when individual populations were analysed separately. Conclusions: Referring to the multiple signalling theory, we propose that especially in women, lateral/frontal correlations support a hypothesis of redundancy of information provided by the frontal and lateral dimension of a given facial attractiveness marker. The absence of a significant correlation in male facial averageness suggests that frontal and lateral averageness may convey different information about an individual.

Paxton D. Culpepper, Jan Havlíček, Juan David Leongómez, S. Craig Roberts (2018)

Resumen:
The emotion of disgust plays a key role in the behavioral immune system, a set of disease-avoidance processes constituting a frontline defense against pathogenic threats. In the context of growing research interest in disgust, as well as recognition of its role in several psychiatric disorders, there is need for an improved understanding of behavioral triggers of disgust and for adequate techniques to both induce disgust in experimental settings and to measure individual variability in disgust sensitivity. In this study, we sought to address these issues using a multi-stage, bottom-up approach that aimed first to determine the most widespread and effective elicitors of disgust across several cultures. Based on exploratory factor analysis of these triggers, revealing four main components of pathogen-related disgust, we then generated a novel visual stimulus set of 20 images depicting scenes of highly salient pathogen risk, along with paired control images that are visually comparable but lack the disgust trigger. We present a series of validation analyses comparing our new stimulus set (the Culpepper Disgust Image Set, C-DIS) with the most commonly used pre-existing set, a series of 7 images devised by Curtis et al. (2004). Disgust scores from participants who rated the two image sets were positively correlated, indicating cross-test concordance, but results also showed that our pathogen-salient images elicited higher levels of disgust and our control images elicited lower levels of disgust. These findings suggest that the novel image set is a useful and effective tool for use in future research, both in terms of priming disgust and for measuring individual differences in disgust sensitivity.

Milena Vásquez-Amézquita, Juan David Leongómez, Michael C. Seto, Mauricio Bonilla, Alexa Rodríguez-Padilla, Alicia Salvador (2018)

Resumen:
Digit ratio (2D:4D) is a marker of prenatal androgenic exposure that is correlated with different behaviour patterns. Here, we explore the relationship between 2D:4D ratio and early versus late attention to sexually preferred stimuli using an eye-tracking paradigm with 78 androphilic or gynephilic men and women. We simultaneously presented preferred and non-preferred adult stimuli and assessed visual attention across time to first fixation and total duration fixation on entire body and three specific areas (face, chest and pelvis), and investigated whether digit ratio was related to visual attentional biases towards sexually preferred stimuli. As expected, participants tended to fixate faster and for more time on the preferred gender. However, we found no significant interactions between 2D:4D and attentional biases towards the preferred gender, for any measure of attention. These results suggest that attention towards the preferred gender is not related to the 2D:4D digit ratio.

Juan David Leongómez, Viktoria R. Mileva, Anthony C. Little, S. Craig Roberts (2017)

Resumen:
Non-verbal behaviours, including voice characteristics during speech, are an important way to communicate social status. Research suggests that individuals can obtain high social status through dominance (using force and intimidation) or through prestige (by being knowledgeable and skillful). However, little is known regarding differences in the vocal behaviour of men and women in response to dominant and prestigious individuals. Here, we tested within-subject differences in vocal parameters of interviewees during simulated job inter-views with dominant, prestigious, and neutral employers (targets), while responding to questions which were classified as introductory, personal, and interpersonal. We found that vocal modulations were apparent between responses to the neutral and high-status targets, with participants, especially those who perceived themselves as low in dominance, increasing fundamental frequency (F0) in response to the dominant and prestigious targets relative to the neutral target. Self-perceived prestige, however, was less related to contextual vocal modulations than self-perceived dominance. Finally, we found that differences in the context of the interview questions participants were asked to respond to (introductory, personal, interpersonal), also affected their vocal parameters, being more prominent in responses to personal and interpersonal questions. Overall, our results suggest that people adjust their vocal parameters according to the perceived social status of the listener as well as their own self-perceived social status.

Mauricio Bonilla, Juan David Leongómez (2017)

Resumen:
La discriminación de las emociones expresadas a nivel facial es importante para las relaciones sociales, la empatía y la interacción social. El objetivo de este estudio fue observar si existían diferencias en el procesamiento cortical ante dos emociones básicas, la ira y el miedo y definir si la percepción de la ira intensa genera una mayor modulación del componente N170 en amplitud y latencia en comparación con las imágenes de rostros con expresión de miedo intenso. Para este estudio se utilizó la técnica de potenciales evocados con un montaje de 32 canales. Se encontraron diferencias significativas en latencia para las imágenes de rostros que expresan ira intensa, comparados con la condición de imágenes de rostros de miedo intenso. Se encontraron diferencias tanto de la amplitud como de latencia ante imágenes de rostros de ira y miedo intensos en comparación con imágenes de rostros neutros.

Kelly D. Cobey, Mike Nicholls,  Juan David Leongómez, S. Craig Roberts (2015)

Resumen:
How to achieve dominance in a group is a recurrent challenge for individuals of many species, including humans. Previous research indicates that both relationship status and contraceptive use appear to moderate women’s testosterone levels. If testos- terone contributes to dominance, this raises the possibility for group differences in dominance between single and partnered women, and between users and non-users of hormonal contraception. Here, we examine associations between relationship status and use/non-use ofhormonal contraception and women’s self-reported social dominance. In a sample of 84 women, we replicate previous research documenting a significant positive correlation between women’s saliva testosterone levels and their self- reported dominance. Consistent with other literature, we also find that women using hormonal contraception have significantly lower testosterone than those who are regularly cycling and that partnered women have significantly lower testosterone than single women. Although we do not find a main effect of either relationship status or hormonal contraceptive use status on women’s reported levels of dominance, the interaction between these variables predicted reported dominance scores. This interac- tion remained significant when participant age and testosterone values were added to the model as covariates. We discuss these results in the context of the existing literature on testosterone and women’s dominance behaviour and with respect to the evolutionary benefits of social dominance in women.

Juan David Leongómez (2015)

Resumen:
La existencia de la música y su origen continúan siendo un misterio. Sin embargo, la ciencia ha logrado proveer respuestas parciales y modelos teóricos, basándose en una variedad de evidencias ha logrado señalar aspectos fundamentales y proponer hipótesis que deben ser estudiadas. Este artículo presenta una revisión de la literatura en cuanto al estudio científico de la música, incluyendo el problema central de los universales en música, la compleja relación entre música y lenguaje y las dificultades de los enfoques evolucionistas en torno a la música. Propone, además, (1) que la ciencia debe estudiar la musicalidad más que la música misma, (2) que es esencial tener en cuenta los diferentes aspectos que componen la musicalidad (que podrían tener desarrollos evolutivos independientes), y (3) que es importante diseñar experimentos y estudios que permitan separar, tanto los aspectos biológicos de los culturales, como eventualmente las posibles adaptaciones de las exaptaciones.