This study investigated sex differences in interest in infants among children, adolescents, young adults, and older individuals. Interest in infants was assessed with responses to images depicting animal and human infants versus adults, and with verbal responses to questionnaires. Clear sex differences, irrespective of age, emerged in all visual and verbal tests, with females being more interested in infants than males. Male interest in infants remained fairly stable across the four age groups, whereas female interest in infants was (...) highest in childhood and adolescence and declined thereafter, particularly for the responses to visual stimuli. The observed developmental changes in female interest in infants are consistent with the hypothesis that they represent a biological adaptation for parenting. (shrink)

The relation between testosterone levels and aggressive behavior is well established. From an evolutionary viewpoint, testosterone can explain at least part of the sex differences found in aggressive behavior. This explanation, however, is mediated by factors such as prenatal testosterone levels and basal levels of cortisol. Especially regarding sex differences in aggression during adolescence, these mediators have great influence. Based on developmental brain structure research we argue that sex differences in aggression have a pre-pubertal origin and (...) are maintained during adolescence. Evidence of prenatal, adolescent, and adult levels of testosterone in relation to aggression taken together, support Archer's argument for sexual selection as the driver of sex differences in aggression. (shrink)

There is increasing interest in the need to address the ethical dilemmas related to the engagement of adolescents in sexual and reproductive health research. Research projects, including those that address issues related to STIs and HIV, adverse pregnancy outcomes, violence, and mental health, must be designed and implemented to address the needs of adolescents. Decisions on when an individual has adequate capacity to give consent for research most commonly use age as a surrogate rather than directly assessing capacity to understand (...) the issues and make an informed decision on whether to participate in research or not. There is a perception that adolescents participating in research are more likely to be coerced and may therefore not fully comprehend the risk they may be taking when engaging in research. This paper examines the various ethical issues that may impact stakeholders' decision making when considering engaging adolescents in SRH research in Nigeria. It makes a case for lowering the age of consent for adolescents. While some experts believe it is possible to extrapolate relevant information from adult research, studies on ethical aspects of adolescents' participation in research are still needed, especially in the field of sexual and reproductive health where there are often differences in knowledge, attitudes and practices compared to adults. The particular challenges of applying the fundamental principles of research ethics to adolescent research, especially research about sex and sexuality, will only become clear if more studies are conducted. (shrink)

Risk-taking behaviors in adolescents have traditionally been analyzed from a psychopathological approach, with an excessive emphasis on their potential costs. From evolutionary theory we propose that risk-taking behaviors can be means through which adolescents obtain potential benefits for survival and reproduction. The present study analyses sex differences in three contexts of risk in the evolutionary specific domains and the predictive value of these domains over risk-taking behaviors, separately in female and male adolescents. 749 adolescents valued their risk perception, expected (...) benefits and risk propensity through the Evolutionary Domain-Specific Risk Scale, as well as their engagement in risk-taking behaviors through the Risky Behavior Questionnaire. Male adolescents showed lower risk perception in two evolutionary domains, expected higher benefits in two other domains and showed higher risk propensity in six domains. Female adolescents showed lower risk perception in two domains. Additionally, risk perception, expected benefits and risk propensity in the evolutionary domains predicted the engagement in risk-taking behaviors in male adolescents, whereas in female adolescents only expected benefits and risk propensity showed a predictive effect over risk-taking behaviors. These results suggest the potential role of evolutionary mechanisms on risk-taking behaviors in adolescents. Results have practical implications for interventions programs aimed at reducing risk-taking behaviors. In addition to considering sex differences, intervention programs should consider alternative behaviors through which adolescents can reach their evolutionary goals, and handle the risks related to those behaviors that cannot be replaced but have potential benefits for adolescents. (shrink)

Difficulty engaging in reciprocal social interactions is a core characteristic of autism spectrum disorder. The mechanisms supporting effective dynamic real-time social exchanges are not yet well understood. This proof-of-concept hyperscanning electroencephalography study examined neural synchrony as the mechanism supporting interpersonal social interaction in 34 adolescents with autism spectrum disorder, age 10–16 years, paired with neurotypical confederates of similar age. The degree of brain-to-brain neural synchrony was quantified at temporo-parietal scalp locations as the circular correlation of oscillatory amplitudes in theta, alpha, (...) and beta frequency bands while the participants engaged in a friendly conversation. In line with the hypotheses, interpersonal neural synchrony was significantly greater during the social interaction compared to the baseline. Lower levels of synchrony were associated with increased behavioral symptoms of social difficulties. With regard to sex differences, we found evidence for stronger interpersonal neural synchrony during conversation than baseline in females with autism, but not in male participants, for whom such condition differences did not reach statistical significance. This study established the feasibility of hyperscanning during real-time social interactions as an informative approach to examine social competence in autism, demonstrated that neural coordination of activity between the interacting brains may contribute to social behavior, and offered new insights into sex-related variability in social functioning in individuals with autism spectrum disorders. (shrink)

This research is part of the last study Drugs and School IX developed in the Basque Country (Spain) by the Instituto Deusto de Drogodependencias (Deusto Institute of Drug Addiction) of the University of Deusto and the data gathered by means of cluster sampling in two stages. The sample is made up of N= 6.007 girls and boys ranging from 12 to 22 years of age in Secondary Education and the aim is to answer the following new research questions based on (...) those parameters: (1) describe the reality of drug consumption and some psychosocial variables in this sample, as well as analyse several relations between variables; (2) analysing the role of school well-being, self-esteem and self-concept regarding consumption; (3) taking a close look at the moderating role of age and gender on the relationship of school well-being, self-concept and self-esteem with consumption; and (4) understand the existing interaction between all these variables, studying the moderating role of self-esteem and self-concept in the influence of school well-being on consumption. Using a correlation, hierarchical regression and mediation analysis with SPSS (v. 26) and Amos (v. 26) applications, three main conclusions were reached. Firstly, that educational and academic well-being, academic self-concept and self-esteem seem to play the role of protecting factors in adolescence, while assertiveness is linked to a higher consumption level. Secondly, that academic self-concept has a mediating effect between well-being and consumption. Some of these relations are moderated by the variables of gender and age. Thirdly, that age and gender are very relevant sociodemographic variables that must be taken into account in order to understand this phenomenon. Age has shown its covariant effect, which is especially relevant in the influence of academic well-being measured as being held back years. It has also proved to be important in order to understand its experiential or experimental and transitory character. Moreover, significant differences in consumptions have been found based on gender. (shrink)

She aimed education current into detecting the relationship between self-compassion and symptoms of physical deformities in adolescents and differences depending on several demographic variables. The study sample consisted of (293) adolescents. The self-compassion scale was used to achieve the objectives of the study. (Neff, Bluth, et al., 2021) The External Appearance Anxiety Scale (Park, 2007) and external rejection sensitivity meter (Roberts et al., 2018). The results of the study indicated that the level of anxiety on the external appearance came (...) with an average degree, as the arithmetic average was (2.63), and that the level of self-compassion among adolescents with physical deformities was at an average level, where the arithmetic average was (3.26), and it was found that there is an influential relationship between self-compassion and sensitivity to rejection due to appearance, as the direct effects have reached 52.2%, and it is also found that sex has a negative impact that is statistically indicative of the relationship between self-compassion And sensitivity to rejection because of appearance, as it turns out that the level of education has a negative impact statistically significant between the relationship between self-compassion and sensitivity rejection because of appearance, and it is also found that weight has a negative effect is statistically significant on the relationship between self-compassion and sensitivity rejection because of appearance. The direct impact of self-compassion on sensitivity to rejection due to appearance reached 36.3%, and sex had a statistically significant adverse effect on the relationship between empathy and deformities. The academic level also has a statistically significant adverse impact on the relationship between self-compassion and distortions. (shrink)

Dual functional brain asymmetry refers to the notion that in most individuals the left cerebral hemisphere is specialized for language functions, whereas the right cerebral hemisphere is more important than the left for the perception, construction, and recall of stimuli that are difficult to verbalize. In the last twenty years there have been scattered reports of sex differences in degree of hemispheric specialization. This review provides a critical framework within which two related topics are discussed: Do meaningful sex (...) class='Hi'>differences in verbal or spatial cerebral lateralization exist? and, if so, Is the brain of one sex more symmetrically organized than the other? Data gathered on right-handed adults are examined from clinical studies of patients with unilateral brain lesions; from dichotic listening, tachistoscopic, and sensorimotor studies of functional asymmetries in non-brain-damaged subjects; from anatomical and electrophysiological investigations, as well as from the developmental literature. Retrospective and descriptive findings predominate over prospective and experimental methodologies. Nevertheless, there is an impressive accummulation of evidence suggesting that the male brain may be more asymmetrically organized than the female brain, both for verbal and nonverbal functions. These trends are rarely found in childhood but are often significant in the mature organism. (shrink)

The present study examined the attitudes of Filipino middle school students toward physical education and the associations between PE attitude and various personal and external correlates of PE. In total, 659 middle school students, aged between 12 and 19 years, participated in the study. The Physical Education Attitude Scale was used to measure affective, cognitive, and motivational/behavioral attitudes of adolescent students toward PE. Results showed that middle school students had moderate general attitudes toward PE. Female students had more favorable attitudes (...) toward PE when their teacher was male than female. When the teacher was female, male students were more satisfied with the PE curriculum than female students. When the teacher was male, female students were more comfortable with the PE curriculum than male students. Finally, students' PE attitude did not decrease as they got older, regardless of student sex. The findings provide a different perspective for the field and underscore the importance of not only the PE curriculum but also the student–teacher relationship. To prevent the decline in students' positive attitude and encourage positive behaviors toward PE and activities, teachers should be very considerate about their interactions with students of the same sex; school administrators, meanwhile, should focus at providing PE teachers with special training courses to enhance both their teaching and communication capabilities. (shrink)

The aim of study was to investigate the relationship between proactive coping strategies and the dimensions of identity formation, along with the role of biological sex and psychological gender as moderators for this relationship. We conducted analyses aimed at showing differences in terms of identity dimensions levels and proactive coping strategies used by a group of individuals with different biological sex and psychological gender. A group of 101 students from upper secondary schools from Pomeranian Voivodeship took part in the (...) study. We used in our research The Dimensions of Identity Development Scale; The Psychological Gender Inventory and The Proactive Coping Inventory for Adolescents. We found, among others, that in the case of a proactive strategy, biological sex turned out to be a significant moderator in the relationship between this variable and identity dimensions: ruminative exploration, commitment-making and identification with commitment. In the case of instrumental support seeking, psychological gender turned out to be a significant moderator for the relationship between these variables and a part of identity dimensions. The obtained results show that, regardless of whether young people, in terms of characteristics that are stereotypically associated with biological sex, are described as aschematic or schematic when entering adulthood and attempting to constitute themselves, more often cope in a task-oriented manner by trying to create a set of information useful in difficult situations and aspire to obtain informational support from individuals in one’s own social network, who are regarded as safe people. (shrink)

Current literature suggesting a shared endophenotype between individuals with anorexia nervosa and autism spectrum disorder related to executive functioning has several limitations: performance-based instead of ecologically valid measures of set-shifting are used, lack of comparisons between same-sex groups, and reliance on adult samples only. This was the first study directly comparing female youth with ASD to female youth with AN using an ecologically valid measure of EF. A secondary data analysis combined caregiver-reported EF on the Behavior Rating Inventory of Executive (...) Functioning for 22 female adolescent youth with AN and 29 female adolescent youth with ASD. EF in each group was compared to population norms, and EF was compared between groups. Compared to population norms, adolescents with AN had elevated scores on shift, initiate, and emotional control scales, and adolescents with ASD had elevated scores on all scales of the BRIEF and were more likely to have scores in the clinical range. There were significant differences between groups on all but three scales. The cognitive profiles and clinical scores of AN females were not comparable to those of ASD females. The findings reveal a clear clinical impairment in females with ASD but not in females with AN. The results do not support the hypothesis of similar real-world EF profiles between these groups. The results encourage further exploration into the similarities and distinctions between these two disorders. (shrink)

Cross-cultural sex differences in mobility and harm avoidance have been widely reported, often emphasizing fitness benefits of long-distance travel for males and high costs for females. Data emerging from adults in small-scale societies, however, are challenging the assumption that female mobility is restricted during reproduction. Such findings warrant further exploration of the ontogeny of mobility. Here, using a combination of machine-learning, mixed-effects linear regression, and GIS mapping, we analyze range size, daily distance traveled, and harm avoidance among Hadza foragers (...) during middle childhood and adolescence. Distance traveled increased with age and, while male adolescents had the longest daily ranges, average daily distance traveled by each sex was similar. We found few age- or sex-related patterns in harm-avoidant responses and a high degree of individual variation. When queried on the same issues, children and their parents were often in alignment as to expectations pertaining to harm avoidance, and siblings tended to behave in similar ways. To the extent that sex differences in mobility did emerge, they were associated with ecological differences in physical threats associated with sex-specific foraging behaviors. Further, we found no strong association between harm avoidance and mobility. Young Hadza foragers of both sexes are highly mobile, regardless of how harm avoidant they are. Taken together, our findings indicate that the causal arrows between harm avoidance and mobility must be evaluated in ecologically specific frameworks where cultural expectations of juvenile mobility can be contextualized. (shrink)

Women have consistently higher levels of disgust than men. This sex difference is substantial in magnitude, highly replicable, emerges with diverse assessment methods, and affects a wide array of outcomes—including job selection, mate choice, food aversions, and psychological disorders. Despite the importance of this far-reaching sex difference, sound theoretical explanations have lagged behind the empirical discoveries. In this article, we focus on the evolutionary-functional level of analysis, outlining hypotheses capable of explaining why women have higher levels of disgust than men. (...) We present four hypotheses for sexual disgust and six for pathogen disgust, along with testable predictions. Discussion focuses on additional new hypotheses and on future research capable of adjudicating among these competing, but not mutually exclusive, hypotheses. (shrink)

Are there sex differences in pain? For experimentally delivered somatic stimuli, females have lower thresholds, greater ability to discriminate, higher pain ratings, and less tolerance of noxious stimuli than males. These differences, however, are small, exist only for certain forms of stimulation and are affected by many situational variables such as presence of disease, experimental setting, and even nutritive status. For endogenous pains, women report more multiple pains in more body regions than men. With no obvious underlying rationale, (...) some painful diseases are more prevalent among females, others among males and, for many diseases, symptoms differ between females and males. Sex differences in attitudes exist that affect not only reporting, coping, and responses to treatment, but also measurement and treatment. So many variables are operative, however, that the most striking feature of sex differences in reported pain experience is the apparent overall lack of them. On the other hand, deduction from known biological sex differences suggests that these are powerful sex differences in the operation of pain mechanisms. First, the vaginal canal provides an additional route in women for internal trauma and invasion by pathological agents that puts them at greater risk for developing hyperalgesia in multiple body regions. Second, sex differences in temporal patterns are likely to give rise to sex differences in how pain is and stimuli are interpreted, a situation that could lead to a greater variability and wider range of pains without obvious peripheral pathology among females. Third, sex differences in the actions of sex hormones suggest pain-relevant differences in the operation of many neuroactive agents, opiate and nonopiate systems, nerve growth factor, and the sympathetic system. Thus, while inductive analysis of existing data demonstrate more similarities than differences in pain experience between females and males, deductive analysis suggests important operational sex differences in its production. (shrink)

Venturing into novel terrain poses physical risks to a female and her offspring. Females have a greater tendency to avoid physical harm, while males tend to have larger range sizes and often outperform females in navigation-related tasks. Given this backdrop, we expected that females would explore a novel environment with more caution than males, and that more-cautious exploration would negatively affect navigation performance. Participants explored a novel, large-scale, virtual environment in search of five objects, pointed in the direction of each (...) object from the origin, and then navigated back to the objects. We found that females demonstrated more caution while exploring as reflected in the increased amounts of pausing and revisiting of previously traversed locations. In addition, more pausing and revisiting behaviors led to degradation in navigation performance. Finally, individual levels of trait harm avoidance were positively associated with the amount of revisiting behavior during exploration. These findings support the idea that the fitness costs associated with long-distance travel may encourage females to take a more cautious approach to spatial exploration, and that this caution may partially explain the sex differences in navigation performance. (shrink)

The present study aimed to quantify the magnitude of sex differences in humans' ability to accurately recognise non-verbal emotional displays. Studies of relevance were those that required explicit labelling of discrete emotions presented in the visual and/or auditory modality. A final set of 551 effect sizes from 215 samples was included in a multilevel meta-analysis. The results showed a small overall advantage in favour of females on emotion recognition tasks (d = 0.19). However, the magnitude of that sex difference (...) was moderated by several factors, namely specific emotion, emotion type (negative, positive), sex of the actor, sensory modality (visual, audio, audio-visual) and age of the participants. Method of presentation (computer, slides, print, etc.), type of measurement (response time, accuracy) and year of publication did not significantly contribute to variance in effect sizes. These findings are discussed in the context of social and biological explanations of sex differences in emotion recognition. (shrink)

Are risk behaviours in adolescence differentiated according to same-sex vs opposite-sex interest? For all respondents a five-point scale of interest in each sex used information from both of the first two in-home waves of the National Longitudinal Study of Adolescent Health (Add Health). Logistic regression predicted the probability of experiencing each risk behaviour from the same-sex and opposite-sex interest scores. Same-sex interests have more effect on emotional risk, and opposite-sex interests have more effect on substance use. Nevertheless, all risk (...) variables except boys’ depression are responsive to both same-sex and opposite-sex interest. The same-sex interest component of risk is attributed to the emotional strain of living with an anomalous sex interest in a heterosexual society. (shrink)

Sex differences in aggressive and risk-taking behaviors have practical implications for sexual integration of military combat units. The social-role theory implies that female soldiers will adapt to their role and display the same aggressive and risk-taking propensities as their male comrades. If sex differences reflect evolved propensities, however, adoption of the soldier's role is unlikely to eliminate those differences.

Several hundred thousand intellectually talented 12-to 13-year-olds have been tested nationwide over the past 16 years with the mathematics and verbal sections of the Scholastic Aptitude Test (SAT). Although no sex differences in verbal ability have been found, there have been consistent sex differences favoring males in mathematical reasoning ability, as measured by the mathematics section of the SAT (SAT-M). These differences are most pronounced at the highest levels of mathematical reasoning, they are stable over time, and (...) they are observed in other countries as well. The sex difference in mathematical reasoning ability can predict subsequent sex differences in achievement in mathematics and science and is therefore of practical importance. To date a primarily environmental explanation for the difference in ability has not received support from the numerous studies conducted over many years by the staff of Study of Mathematically Precocious Youth (SMPY) and others. We have studied some of the classical environmental hypotheses: attitudes toward mathematics, perceived usefulness of mathematics, confidence, expectations/ encouragement from parents and others, sex-typing, and differential course-taking. In addition, several physiological correlates of extremely high mathematical reasoning ability have been identified (left-handedness, allergies, myopia, and perhaps bilateral representation of cognitive functions and prenatal hormonal exposure). It is therefore proposed that the sex difference in SAT-M scores among intellectually talented students, which may be related to greater male variability, results from both environmental and biological factors. (shrink)

This study examines the family environments and hormone profiles of 316 individuals aged 2 months-58 years residing in a rural village on the east coast of Dominica, a former British colony in the West Indies. Fieldwork was conducted over an eight-year period (1988–1995). Research methods and techniques include radioimmunoassay of cortisol and testosterone from saliva samples (N=22,340), residence histories, behavioral observations of family interactions, extensive ethnographic interview and participant observation, psychological questionnaires, and medical examinations.Analyses of data indicate complex, sex-specific effects (...) of family environment on endocrine function. Male endocrine profiles exhibit greater sensitivity to presence of father than do female endocrine profiles. Father-absent males tend to have (a) low cortisol levels during infancy, (b) high or abnormal cortisol profiles during childhood and adolescence, and (c) high cortisol and low testosterone levels during adulthood compared with those of males raised with a resident father. These results indicate that early family environment has significant effects on endocrine response throughout male life histories. (shrink)

The evidence favoring sex differences in pain seems compelling (berkley). This commentary considers the role of such factors as anxiety, somatosensory amplification, and coping style in accounting for the differential response to pain in the laboratory and clinic, and emphasizes the need to base evaluation and treatment upon individual reports rather than gender-based stereotypes.

The contribution of this research lies in its dual approach to the question of physical activity (PA) among adolescents, combining objective measurement of PA by teenagers and a comparison of psychological satisfaction through physical activities involving differing degrees of autonomy (i.e., organized or unstructured). Using the conceptual framework of Self-Determination Theory, the analysis also examines the relationship between levels of PA among adolescents and physical self-concept and satisfaction of basic psychological needs during exercise. The study surveyed 129 first-year higher secondary (...) education students from schools in the city of A Coruña. Satisfaction of basic psychological needs during organized and unstructured physical activities was measured using the Basic Psychological Needs in Exercise Scale. PA levels were assessed based on step count per day for a week as measured by an accelerometer. The results show that the daily step average recorded by students (7,400) is below the minimum recommended levels of PA for this age group, that students are more active on weekdays than at the weekend, and that there is no significant difference in PA levels between male and female subjects ( T = 0.23, p d = 0.04). Findings from the comparative analysis of the three basic psychological needs show greater satisfaction of the need for autonomy during unstructured activities ( T = 6.15, p d = 0.68), and greater satisfaction of the need for competence during organized activities ( T = −2.50, p d = 0.27). No variation in terms of sex was found in relation to satisfaction of the need for autonomy or relatedness from unstructured activities; however, girls showed notably lower satisfaction than boys in relation to the need for competence ( T = −2.62, p d = 0.49). Self-esteem was found to play an important mediating role and observed to be strongly related to sex ( T = −5.16, p d = 0.90). Organized PA was found to provide greater need satisfaction among boys than girls across all categories. The study showed no relationship between psychological variables and objectively measured PA (Pillai’s trace: F = 0.86, p > 0.05, η 2 = 0.08, observed power = 0.66). Basic psychological needs show significant positive interrelation between them and a significant positive relationship between them and physical self-concept, as expected based on previous literature. (shrink)

Background: Losing one’s only child may lead to post-traumatic stress disorder, of which re-experiencing is the core symptom. However, neuroimaging studies of sex differences in re-experiencing in the context of the trauma of losing one’s only child and PTSD are scarce; comparisons of the functional networks from the hippocampal subfields to the thalamus might clarify the neural basis.Methods: Thirty couples without any psychiatric disorder who lost their only child, 55 patients with PTSD, and 50 normal controls underwent resting-state functional (...) magnetic resonance imaging. The functional connectivity from the hippocampal subregions to the thalamus and the correlations of FC with re-experiencing symptoms were analyzed within and between the sexes.Results: Compared with husbands without PTSD, wives without PTSD had higher re-experiencing symptoms and weaker FC between the right hippocampal cornu ammonis 3 and the right thalamus. Moreover, only the correlation between the RCA3-RT FC and re-experiencing in wives without PTSD was significant. Among the three groups, only the RCA3-RT FC in female subjects was markedly different. Additionally, the RCA3-RT FC in wives without PTSD was remarkably lower relative to female patients with PTSD.Conclusion: Wives without PTSD who lost their only child had worse re-experiencing symptoms relative to their husbands, which was associated with the FC alteration between the hippocampal subregions and the thalamus. Importantly, the low level of the RCA3-RT FC may play a potentially protective role against the development of PTSD in wives who have lost their only child. (shrink)

BackgroundBoth impairment and sex differences in social cognition and neurocognition have been documented in schizophrenia. However, whether sex differences exist in the association between social cognition and neurocognition are not known. We aimed to investigate the contribution of areas of neurocognition to theory of mind and hostility bias, representing social cognition, according to sex in early course schizophrenia.MethodsIn this cross-sectional study, we assessed neurocognition using the Japanese version of the Brief Assessment of Cognition in Schizophrenia and assessed the (...) ToM and hostility bias subdomains of social cognition using the Social Cognition Screening Questionnaire in 131 participants diagnosed with schizophrenia within 5 years of onset. Sex differences were analyzed using t-tests. The associations of neurocognitive subdomains with ToM and hostility bias according to sex were analyzed using multiple regression analysis. Results were adjusted by age, estimated premorbid intelligence quotient, and symptomatology.ResultsNo sex differences were found in ToM or hostility bias. Higher verbal fluency was significantly associated with higher ToM in females, whereas higher executive function was significantly associated with higher ToM in males. Higher verbal fluency was significantly associated with lower hostility bias in females, whereas neurocognition and hostility bias were not significantly associated in males.ConclusionThe results suggest that neurocognition associated with social cognition differ according to sex. These differences should be considered for more effective treatment of social cognition. (shrink)

Prior studies have reported that women outperform men in nonverbal communication, including the recognition of emotions through static facial expressions. In this experimental study, we investigated sex differences in the estimation of states of happiness, anger, fear, and disgust through static photographs using a two-culture approach. This study was conducted among the Tuvans and Mongolian people from Southern Siberia. The respondents were presented with a set of photographs of men and women of European and Tuvan origin and were asked (...) to interpret each of them. They were asked: “What does the person in the photo feel?” We found that the Tuvans easily identified happiness and anger; however, the level of accuracy of fear and disgust recognition was low. No sex differences in the recognition of happiness, disgust, and fear were observed. However, anger recognition was significantly moderated by the perceiver’s sex and the origin of the model. Compared to Tuvan men, Tuvan women were significantly less accurate in identifying anger in male Tuvans. Furthermore, the age effect was found in recognition of fear: older Tuvans were more accurate while recognizing the fearful faces of Tuvan, but not the European models. (shrink)

Contemporary mate preferences can provide important clues to human reproductive history. Little is known about which characteristics people value in potential mates. Five predictions were made about sex differences in human mate preferences based on evolutionary conceptions of parental investment, sexual selection, human reproductive capacity, and sexual asymmetries regarding certainty of paternity versus maternity. The predictions centered on how each sex valued earning capacity, ambition— industriousness, youth, physical attractiveness, and chastity. Predictions were tested in data from 37 samples drawn (...) from 33 countries located on six continents and five islands. For 27 countries, demographic data on actual age at marriage provided a validity check on questionnaire data. Females were found to value cues toresource acquisitionin potential mates more highly than males. Characteristics signalingreproductive capacitywere valued more by males than by females. These sex differences may reflect different evolutionary selection pressures on human males and females; they provide powerful cross-cultural evidence of current sex differences in reproductive strategies. Discussion focuses on proximate mechanisms underlying mate preferences, consequences for human intrasexual competition, and the limitations of this study. (shrink)

IntroductionAlthough a few studies suggest that young overweight to obese children and adolescents may have impaired postural control compared to young normal-weight peers, little information exists about how these two groups differ in the quality of the underlying balance strategies employed. Hence, the aim of the present study was a first comprehensive examination of the structural complexity of postural sways in these two cohorts during quiet bilateral standing.MethodsNineteen YO secondary school students were carefully matched to YN controls for age, sex, (...) height, and school. Mediolateral and anteriorposterior acceleration signals were recorded with an inertial measurement unit positioned at the trunk while standing barefoot in two conditions: firm and foam support surface. The magnitude of postural fluctuations was obtained using the root mean square. The temporal structure of the signals was analyzed via sample entropy, largest Lyapunov exponent, and detrended fluctuation analysis algorithm. Reliability was assessed using a test–retest design.ResultsIn both groups, foam standing caused higher postural fluctuations and reduced structural complexity. In comparison to YN, YO exhibited a higher RMSAP. Especially in ML direction, the acceleration signals of the YO had higher repeatability, greater long-range correlations, and lower local stability. However, these observations were largely independent of the task difficulty. Except for α-DFAAP, the IMU approach proved reliable to characterize posture control.DiscussionOur outcomes confirm postural control deficits in YO compared to their YN peers and indicate impaired regulatory mechanisms reflected as rigidity. Such less complex patterns usually reflect diverse pathologies, are detrimental to compensate for internal or external perturbations, and are attributed to lower adaptability and task performance. Without targeted balance stimuli, YO likely end in a lifelong vicious circle of mutually dependent poor balance regulation and low physical activity. (shrink)

Archer examines sex differences in aggression, and argues that these differences may be better explained by sexual selection theory than by social role theory. This commentary examines sex differences in the developmental antecedents of aggression and violence, and presents a preliminary framework for examining whether the observed sex differences amongst these developmental antecedents can also be accounted for by sexual selection theory.

Previous meta-analyses support a female advantage in decoding non-verbal emotion (Hall, 1978, 1984), yet the mechanisms underlying this advantage are not understood. The present study examined whether the female advantage is related to greater female attention to the eyes. Eye-tracking techniques were used to measure attention to the eyes in 19 males and 20 females during a facial expression recognition task. Women were faster and more accurate in their expression recognition compared with men, and women looked more at the eyes (...) than men. Positive relationships were observed between dwell time and number of fixations to the eyes and both accuracy of facial expression recognition and speed of facial expression recognition. These results support the hypothesis that the female advantage in facial expression recognition is related to greater female attention to the eyes. (shrink)

A mime presented on videotape Adler’s six great ideas of truth, goodness, beauty, liberty, equality, and justice; their opposites; and the transitions from the positive or “good” concepts to their opposites. Using Johansson’s (1973) technique, the performer’s 12 joints were marked with points of light. Overall, the viewers had marginal success in identifying the concepts, but females were much more successful than males in identifying the “bad” ones of evil, slavery, falsehood, and ugliness, averaging 62% correct to the males’ 23%. (...) The results agree with Hall’s (1984) discussion of sex differences in the interpretation of nonverbal behavior. (shrink)

I ask three questions related to the claims made within the staying alive theory : Is survival more fitness-enhancing for females than for males? Does the historical record on sex differences in mortality support the SAT? Is it possible to talk about “independent selective pressures on both male and female traits” when all we have are sex/gender comparisons?

The argument of berkley for the existence sex differences in pain is based on biological factors. We suggest that the psychological evidence for such differences is more substantial.

The central premise is that a significant amount of sex offending stems from unusual or inappropriate sexual preferences that appear in early adolescence, are relatively stable, and immutable. In those ways, they are like more ordinary sexual preferences, generating sexual impulses that are insistent. Individuals are strongly tempted to act on them, alternatives to satisfying them are unfulfilling, and complete long-term control of such impulses is unlikely. Yet, since individuals with sexual preferences for inappropriate objects or activities are neither (...) morally nor legally permitted to act on them, they find themselves in a terrific bind. The public is, to some extent, correct to not trust the individuals with such preferences and to attempt to monitor or control them. However, most such efforts appear ineffective and counterproductive. Recidivist sex offenders are particularly worrisome. The possibility of voluntary castration for such offenders, in lieu of preventive detention or other more restrictive measures, is explored. (shrink)

Women typically report more pain than men, as well as exhibit specific sex differences in the perception and emotional expression of pain. We present evidence that sex is a significant variable in the evolution of facial expression of pain.

Geary proposes a sociobiological hypothesis of how sex differences in math and spatial skills might have jointly arisen. His distinction between primary and secondary math skills is noteworthy, and in some ways analogous to the closed versus open systems postulated to exist for language. In this commentary issues concerning how genes might affect complex cognitive skills, the interpretation of heritability estimates, and prior research abilites are discussed.

The principles of sexual selection were used as an organizing framework for interpreting cross-national patterns of sex differences in mathematical abilities. Cross-national studies suggest that there are no sex differences in biologically primary mathematical abilities, that is, for those mathematical abilities that are found in all cultures as well as in nonhuman primates, and show moderate heritability estimates. Sex differences in several biologically secondary mathematical domains are found throughout the industrialized world. In particular, males consistently outperform females (...) in the solving of mathematical word problems and geometry. Sexual selection and any associated proximate mechanisms influence these sex differences in mathematical performance indirectly. First, sexual selection resulted in greater elaboration in males than in females of the neurocognitive systems that support navigation in three-dimensional space. Knowledge implicit in these systems reflects an understanding of basic Euclidean geometry, and may thus be one source of the male advantage in geometry. Males also use more readily than females these spatial systems in problem-solving situations, which provides them with an advantage in solving word problems and geometry. In addition, sex differences in social styles and interests, which also appear to be related in part to sexual selection, result in sex differences in engagement iii mathematics-related activities, thus further increasing the male advantage in certain mathematical domains. A model that integrates these biological influences with sociocultural influences on the sex differences in mathematical performance is presented in this article. (shrink)

Vigil's socio-relational framework of sex differences in emotion-expressive behavior has a number of interesting aspects, especially the principal concepts of reciprocity potential and perceived attractiveness and trustworthiness. These are attractive and potentially heuristic ideas. However, some of his arguments and claims are not well grounded in research on early development. Three- to five-year-old children did not show the sex differences in emotion-expressive behavior discussed in the target article. Our data suggest that Vigil may have underestimated the roles of (...) epigenetic and cultural factors in shaping emotion-expressive behavior. (shrink)

Although moral psychologists and feminist moral theorists emphasize males’ interest in justice or fairness and females’ interest in care or empathy, recent work in evolutionary psychology links females’ interests in care and empathy for others with interests in fairness and equality. In an important work on sex differences in cognitive abilities, David Geary (1998) argues that the evolutionary mechanism of sexual selection drives the evolution of particular cognitive abilities and selection for particular interests. I mount two main challenges to (...) Geary’s claims. First, I argue that female social and intrasexual competitive environments evolve, which challenges the assumption that such environments are largely nonkin-based and characterized by reciprocity. Second, I grant Geary’s entire characterization of female environments, but argue that the natures of reciprocal relationships themselves do not require and may not select for interests in fairness and equality. This analysis not only challenges claims regarding sex differences in moral interests, but also suggests the need for a diachronic model of male and female social and intrasexual competitive environments. In addition, I propose a return to Trivers’s (1971) focus on the suite of emotions underlying reciprocal altruism as properties and features of individuals as fodder for selection. (shrink)

The learning of immediate causation within a dynamic environment was examined. Participants encountered seven decision points in which they needed to choose which of three possible candidates was the cause of explosions in the environment. Each candidate was firing a weapon at random every few seconds, but only one of them produced an immediate effect. Some participants showed little learning, but most demonstrated increases in accuracy across time. On average, men showed higher accuracy and shorter latencies that were not explained (...) by differences in self-reported prior video game experience. This result suggests that prior reports of sex differences in causal choice in the game are not specific to situations involving delayed or probabilistic causal relations. (shrink)

Sex differences in willingness to take physical risks and in concern for peer esteem may be relevant to whether women should serve in combat, since two major fears soldiers experience are of being injured and of not measuring up as warriors. Women's relative aversion to nonphysical risk may have workplace implications, since risk taking is an attribute of most successful executives.

Modern attitudes to meat in both men and women reflect a strong meat-masculinity association. Sex differences in the relationship between meat and masculinity have not been previously explored. In the current study we used two IATs (implicit association tasks), a visual search task, and a questionnaire to measure implicit and explicit attitudes toward meat in men and women. Men exhibited stronger implicit associations between meat and healthiness than did women, but both sexes associated meat more strongly with ‘healthy’ than (...) ‘unhealthy’ concepts. As ‘healthy’ was operationalized in the current study using terms such as “virile” and “powerful,” this suggests that a meat-strength/power association may mediate the meat-masculinity link readily observed across western cultures. The sex difference was not related to explicit attitudes to meat, nor was it attributable to a variety of other factors, such as a generally more positive disposition toward meat in men than women. Men also exhibited an attention bias toward meats, compared to non-meat foods, while females exhibited more caution when searching for non-meat foods, compared to meat. These biases were not related to implicit attitudes, but did tend to increase with increasing hunger levels. Potential ultimate explanations for these differences, including sex differences in bio-physiological needs and receptivity to social signals are discussed. (shrink)

The current study examines patterns of attachment/self-protective strategies and rates of unresolved loss/trauma in children and adolescents presenting to a multidisciplinary gender service. Fifty-seven children and adolescents (8.42–15.92 years; 24 birth-assigned males and 33 birth-assigned females) presenting with gender dysphoria participated in structured attachment interviews coded using dynamic-maturational model (DMM) discourse analysis. The children with gender dysphoria were compared to age- and sex-matched children from the community (non-clinical group) and a group of school-age children with mixed psychiatric disorders (mixed psychiatric (...) group). Information about adverse childhood experiences (ACEs), mental health diagnoses, and global level of functioning was also collected. In contrast to children in the non-clinical group, who were classified primarily into the normative attachment patterns (A1-2, B1-5, and C1-2) and who had low rates of unresolved loss/trauma, children with gender dysphoria were mostly classified into the high-risk attachment patterns (A3-4, A5-6, C3-4, C5-6, and A/C) (χ2= 52.66;p< 0.001) and had a high rate of unresolved loss/trauma (χ2= 18.64;p< 0.001). Comorbid psychiatric diagnoses (n= 50; 87.7%) and a history of self-harm, suicidal ideation, or symptoms of distress were also common. Global level of functioning was impaired (range 25–95/100; mean = 54.88;SD= 15.40; median = 55.00). There were no differences between children with gender dysphoria and children with mixed psychiatric disorders on attachment patterns (χ2= 2.43;p= 0.30) and rates of unresolved loss and trauma (χ2= 0.70;p= 0.40).Post hocanalyses showed that lower SES, family constellation (a non-traditional family unit), ACEs—including maltreatment (physical abuse, sexual abuse, emotional abuse, neglect, and exposure to domestic violence)—increased the likelihood of the child being classified into a high risk attachment pattern. Akin to children with other forms of psychological distress, children with gender dysphoria present in the context of multiple interacting risk factors that include at-risk attachment, unresolved loss/trauma, family conflict and loss of family cohesion, and exposure to multiple ACEs. (shrink)