Sex differences in the predictability of risk-taking behavior

Sex mechanisms as nonbinary influences on cognitive diversity

Essentially all neuropsychiatric diagnoses show some degree of sex and/or gender differences in their etiology, diagnosis, or prognosis. As a result, the roles of sex-related variables in behavior and cognition are of strong interest to many, with several lines of research showing effects on executive functions and value-based decision making in particular. These findings are often framed within a sex binary, with behavior of females described as less optimal than male "defaults"-- a framing that pits males and females against each other and deemphasizes the enormous overlap in fundamental neural mechanisms across sexes. Here, we propose an alternative framework in which sex-related factors encompass just one subset of many sources of valuable diversity in cognition. First, we review literature establishing multidimensional, nonbinary impacts of factors related to sex chromosomes and endocrine mechanisms on cognition, focusing on value- based decision-making tasks. Next, we present two suggestions for nonbinary interpretations and analyses of sex-related data that can be implemented by behavioral neuroscientists without devoting laboratory resources to delving into mechanisms underlying sex differences. We recommend (1) shifting interpretations of behavior away from performance metrics and towards strategy assessments to avoid the fallacy that the performance of one sex is worse than another; and (2) asking how much variance sex explains in measures and whether any differences are mosaic rather than binary, to avoid assuming that sex differences in separate measures are inextricably correlated. Nonbinary frameworks in research on cognition will allow neuroscience to represent the full spectrum of brains and behaviors.

Sexual Selection Increases Male Behavioral Consistency in Drosophila melanogaster

AbstractSexual selection has been suggested to influence the expression of male behavioral consistency. However, despite predictions, direct experimental support for this hypothesis has been lacking. Here, we investigated whether sexual selection altered male behavioral consistency in Drosophila melanogaster-a species with both pre- and postcopulatory sexual selection. We took 1,144 measures of locomotor activity (a fitness-related trait in D. melanogaster) from 286 flies derived from replicated populations that have experimentally evolved under either high or low levels of sexual selection for >320 generations. We found that high sexual selection males were more consistent (decreased within-individual variance) in their locomotor activity than male conspecifics from low sexual selection populations. There were no differences in behavioral consistency between females from the high and low sexual selection populations. Furthermore, while females were more behaviorally consistent than males in the low sexual selection populations, there were no sex differences in behavioral consistency in high sexual selection populations. Our results demonstrate that behavioral plasticity is reduced in males from populations exposed to high levels of sexual selection. Disentangling whether these effects represent an evolved response to changes in the intensity of selection or are manifested through nongenetic parental effects represents a challenge for future research.

The Obesity Paradox in the Pediatric Trauma Patient

BACKGROUND

Obesity is a chronic disease that adversely impacts patient outcomes and increasingly affecting the pediatric population. According to the CDC, in 2020 the prevalence of obesity among children and adolescents was estimated to be as high as 19.7%. The obesity paradox is the increased survival for overweight and obese adult trauma patients when compared to patients with healthy weights. The aim of this study was to analyze the impact of BMI and outcomes in the pediatric trauma population.

METHODS

Trauma patients in the 2-18 years age group and reported to the 2017-2019 National Trauma Data Bank were identified. CDC growth charts and z-scores were calculated to categorize patients into four subgroups: underweight (<5th percentile), healthy weight (5th-85th percentile), overweight (85th-95th percentile), and obesity (>95th percentile). Primary outcome studied was the mortality rate. Secondary outcomes included injury severity score (ISS), hospital length of stay (LOS), ICU LOS, and number of days on a ventilator. Continuous and categorical data were analyzed using ANOVA and Chi-squared test, respectively, using the healthy BMI category as reference group. P < 0.05 was considered significant.

RESULTS

A total of 161,458 patients [Underweight: 9148 (6%), Healthy weight: 88,009 (55%), Overweight: 26,740 (17%), and Obese: 37,561 (23%)] were included. The mean age was 11 years (SD:5.1). Total mortality for the patient set was 1825 (1.13%). The lowest mortality rate was in the obese group. The ISS was lowest in the obese group, while ICU LOS and days on ventilator were no different than control patients. Hospital LOS and transfer to rehabilitation rates were higher in the obese population.

CONCLUSION

Obesity appears to have a protective effect on mortality and significantly better secondary outcomes in the pediatric trauma population. Further study is necessary to evaluate the interplay between body weight and outcomes in pediatric trauma and disease states.

LEVEL OF EVIDENCE

III.

Flour beetles prefer corners over walls and are slowed down with increasing habitat complexity

Movement affects all key behaviours in which animals engage, including dispersal and habitat use. The red flour beetle, known as a cosmopolitan pest of stored products, was the subject of our study. We examined whether the beetles preferred corners, walls or open areas, and how turns or obstacles in corridors delayed the beetles' arrival at a target cell. Beetles spent significantly more time in corners than expected by chance, while they spent considerably less time in open areas than expected. However, no significant difference was observed between areas with two or three surrounding walls. This could be attributed to the beetles' stronger attraction to corners than crevices or the insufficient proximity of the third wall to the other two. Movement through the corridor was delayed by turns or obstacles, expressed in arrival probabilities, arrival times, time in the corridor or movement speed. Obstacles on the corridor's perimeter had a stronger effect on the beetle movement than those in the corridor's centre owing to the beetles' tendency to follow walls. The research is important also for applied purposes, such as better understanding beetle movement, how to delay their arrival to new patches, and where to place traps.

Phylogenetic meta-analysis reveals system-specific behavioural type-behavioural predictability correlations

The biological significance of behavioural predictability (environment-independent within-individual behavioural variation) became accepted recently as an important part of an individual's behavioural strategy besides behavioural type (individual mean behaviour). However, we do not know how behavioural type and predictability evolve. Here, we tested different evolutionary scenarios: (i) the two traits evolve independently (lack of correlations) and (ii) the two traits' evolution is constrained (abundant correlations) due to either (ii/a) proximate constraints (direction of correlations is similar) or (ii/b) local adaptations (direction of correlations is variable). We applied a set of phylogenetic meta-analyses based on 93 effect sizes across 44 vertebrate and invertebrate species, focusing on activity and risk-taking. The general correlation between behavioural type and predictability did not differ from zero. Effect sizes for correlations showed considerable heterogeneity, with both negative and positive correlations occurring. The overall absolute (unsigned) effect size was high (Zr = 0.58), and significantly exceeded the null expectation based on randomized data. Our results support the adaptive scenario: correlations between behavioural type and predictability are abundant in nature, but their direction is variable. We suggest that the evolution of these behavioural components might be constrained in a system-specific way.

Reasons, Form of Ingestion and Side Effects Associated with Consumption of Amanita muscaria

In recent months, there has been a new trend involving the consumption of Amanita muscaria. The aim of this article was to investigate the reasons for consumption, the form taken and the adverse symptoms that were indicated by those consuming Amanita muscaria. After analysing 5600 comments, 684 people were included in the study, who, in social media groups such as Facebook, stated the purpose of consuming the mushroom (n = 250), the form of mushroom they were taking (n = 198) or the adverse symptoms they experienced (n = 236). The gender of the subjects differentiated the parameters analysed. In the study group of women, the main purpose of consuming Amanita muscaria was to reduce pain, as well as to reduce skin problems, while in men it was mainly to relieve stress, reduce the severity of depressive symptoms and reduce insomnia (p < 0.001). With regard to the form of mushroom ingested, tincture was predominant in the women's study group, while dried was predominant in the men (p < 0.001). In terms of side effects, women reported primarily headaches, while men reported nausea, vomiting, abdominal pain and drowsiness (p < 0.001). Advanced research on Amanita muscaria should be carried out to make the community aware of the toxicity of this fungus.

Sex differences in the predictability of risk-taking behavior

Recent research has found that individuals often vary in how consistently they express their behavior over time (i.e., behavioral predictability) and suggested that these individual differences may be heritable. However, little is known about the intrinsic factors that drive variation in the predictability of behavior. Indeed, whether variation in behavioral predictability is sex-specific is not clear. This is important, as behavioral predictability has been associated with vulnerability to predation, suggesting that the predictability of behavioral traits may have key fitness implications. We investigated whether male and female eastern mosquitofish (Gambusia holbrooki) differed in the predictability of their risk-taking behavior. Specifically, over a total of 954 behavioral trials, we repeatedly measured risk-taking behavior with three commonly used assays-refuge-use, thigmotaxis, and foraging latency. We predicted that there would be consistent sex differences in both mean-level risk-taking behavior and behavioral predictability across the assays. We found that risk-taking behavior was repeatable within each assay, and that some individuals were consistently bolder than others across all three assays. There were also consistent sex differences in mean-level risk-taking behavior, with males being bolder across all three assays compared to females. In contrast, both the magnitude and direction of sex differences in behavioral predictability were assay-specific. Taken together, these results highlight that behavioral predictability may be independent from underlying mean-level behavioral traits and suggest that males and females may differentially adjust the consistency of their risk-taking behavior in response to subtle changes in environmental conditions.