Sex differences in young gymnasts' postural steadiness

The present study examined the differences between male and female gymnasts in bipedal standing position, back standing scale, and stork standing scale testing. 29 young gymnasts (13 boys, 16 girls; ages 12 to 15 years) participated. A portable posturographic digital platform was used to record foot pressure (Foot Checker, Comex SA). Barefoot sole area (cm2), maximal pressure (kPa), center of foot pressure (CoP), sway area (mm2), and CoP linear distance displacement (mm) were analyzed in an integrated software module (Foot Checker, Version 4.0). The intra-class correlation coefficient and the coefficient of variation supported the reliability of the measurements. Results indicated no differences between boys and girls on height, weight, and Body Mass Index. Differences indicated better performance by girls compared to boys in back standing and stork standing.     

Sex differences in parental directives to young children

This study investigated how children learn sex-associated strategies for requesting action. We compared the directives which mothers and fathers address to their 2 1/2- to 5-year-old children. Ten children, 5 boys and 5 girls, engaged separately with each parent in a construction task. Fathers produced more directives than mothers and tended to phrase them as imperatives (e.g., Put the screw in) or as highly indirect “hints” (e.g., The wheel's going to fall off) more often than mothers, who relied more on relatively transparent indirect forms (e.g., Can you put the screw in?). There were no differences in the form of the directives addressed to girls and boys, nor were there any cross-sex effects. Parental modeling, rather than differential socialization of girls and boys, appears to be the mechanism by which children learn to request action in sex-associated ways.     

Sex differences and properties of the decreasing force during sustained static grip at various target forces

The purpose of this study was to examine properties and sex differences of the decreasing force during sustained isometric grip using various target forces, 50%, 75%, and 100% of maximal voluntary contraction (MVC), for 6 min. Participants were healthy, 15 men (height = 172.9 +/- 4.6 cm, body mass = 67.7 +/- 5.36 kg) and 15 women (height = 160.9 +/- 5.4 cm, body mass = 55.9 +/- 5.36 kg). The force decrease for target forces of 75% and 100% MVC was marked until 60 sec. from the onset of grip and then decreased gradually. On the other hand, the target force of 50% MVC was maintained for about 60 sec. and then decreased markedly until 100 sec. Differences in the decreasing force among target force levels was observed until 60 sec., and there were no significant differences of the time to decay to 20%, 30%, and 40% MVC. Namely, the time and force exertion reaching an almost steady state were considered to be almost the same at any target force. A sex difference on a parameter was found after 60 sec. or a decreasing force after 40% MVC, and women held it longer or higher than the men. However, the tendency was smaller in the latter phase of the steady state.     

Sex differences in proxemic behavior and personal space schemata in young children

Spatial preferences with feltboard figures, observed interpersonal distance, and sex-role identification were examined in 80 preschool children. On the feltboard measure, 4- to 5-year-olds chose generally greater interpersonal distance than younger children. Sex of stimulus figure also influenced older children's distance choices. When same-sex pair play was videotaped, older boys spent significantly more time at far distances and less time at close distances than younger boys. A positive correlation between sex-role identification, measured by the Rabban toy choice task, and feltboard figure distance was obtained for older boys only. Findings supported the notion that sex-related interpersonal spatial norms may be learned during the preschool years, particularly by boys.This study is based on a doctoral dissertation written by the author and submitted in partial fulfillment of the requirements for the Ph.D. degree at Michigan State University, 1974.     

Sex differences in jealousy in response to infidelity: Evaluation of demographic moderators in a national random sample

Studies examining sex differences in jealousy have often relied on student samples and were restricted to the evaluation of a selected few moderators. In this study, a nationally representative survey of American households was presented with either an actual or a hypothetical infidelity scenario (which appeared as either a forced choice or as continuous measures). Significant sex differences only emerged for forced choice measures and not for continuous measures. Importantly, this effect appeared most strongly in participants reporting reactions to an actual infidelity. We also explored a number of potential moderators of this effect. These moderators were more influential for the hypothetical than for the actual infidelity scenario. Exploratory analysis of additional demographic variables was conducted.     

Sex and ear differences in spontaneous and click-evoked otoacoustic emissions in young adults

Effects of sex and handedness on the production of spontaneous and click-evoked otoacoustic emissions (OAEs) were explored in a non-hearing impaired population (ages 17-25 years). A sex difference in OAEs, either produced spontaneously (spontaneous OAEs or SOAEs) or in response to auditory stimuli (click-evoked OAEs or CEOAEs) has been reported in infants and children, but healthy young adults seldom have been the target of study. In the current data, a robust sexual dimorphism was confirmed, with women producing more numerous and stronger SOAEs, and CEOAEs with greater response amplitude compared to men. A right-ear advantage was found for the number of SOAEs produced and, in women, for SOAE power. Although handedness did not moderate the ear asymmetry in production, exploratory analyses revealed that departures from strong right hand preference were associated in the present sample with reduced numbers or strengths of OAEs. The results are discussed with respect to differential exposure to androgens during prenatal development.     

Sex differences in impulsivity: a meta-analysis

Men are overrepresented in socially problematic behaviors, such as aggression and criminal behavior, which have been linked to impulsivity. Our review of impulsivity is organized around the tripartite theoretical distinction between reward hypersensitivity, punishment hyposensitivity, and inadequate effortful control. Drawing on evolutionary, criminological, developmental, and personality theories, we predicted that sex differences would be most pronounced in risky activities with men demonstrating greater sensation seeking, greater reward sensitivity, and lower punishment sensitivity. We predicted a small female advantage in effortful control. We analyzed 741 effect sizes from 277 studies, including psychometric and behavioral measures. Women were consistently more punishment sensitive (d = -0.33), but men did not show greater reward sensitivity (d = 0.01). Men showed significantly higher sensation seeking on questionnaire measures (d = 0.41) and on a behavioral risk-taking task (d = 0.36). Questionnaire measures of deficits in effortful control showed a very modest effect size in the male direction (d = 0.08). Sex differences were not found on delay discounting or executive function tasks. The results indicate a stronger sex difference in motivational rather than effortful or executive forms of behavior control. Specifically, they support evolutionary and biological theories of risk taking predicated on sex differences in punishment sensitivity. A clearer understanding of sex differences in impulsivity depends upon recognizing important distinctions between sensation seeking and impulsivity, between executive and effortful forms of control, and between impulsivity as a deficit and as a trait.     

Sex differences in response to a panicogenic challenge procedure: an experimental evaluation of panic vulnerability in a non-clinical sample

Epidemiological studies show that women are twice as likely as men to develop panic disorder (PD) during their lifetimes. Data from retrospective studies also suggest that women are more distressed by panic and other negative emotional states than men, and that this tendency may precede the development of PD. The present prospective study sought to expand this work by evaluating sex differences in the predisposition to panic in individuals without PD or other forms of psychopathology. Participants (N=96; 52 women) were exposed to 12 panicogenic inhalations of 20% CO2-enriched air while physiological (e.g., heart rate, electrodermal response, Frontalis EMG) and self-report (e.g., subject distress, fear, frequency and severity of DSM-IV panic symptoms) response domains were monitored. As expected, magnitude of autonomic responding failed to reliably discriminate between women and men. Yet, women reported more fear and panic immediately following the challenge procedure relative to men, and this sex difference persisted when assessed again 30 min post-challenge. Implications of these results are discussed broadly in the context of biopsychosocial accounts of sex differences in the clinical presentation of PD.     

Sex differences in bystander intervention in a theft

A series of studies demonstrated a strong relationship among the situation-defining variable of degree of harm to victim, sexual configuration among participants, and bystanders' willingness to intervene to stop a theft. A pretest showed that a prior verbal commitment was absolutely necessary for intervention. The remaining data showed that high harm to a victim produced a high rate of intervention and showed strong sex differences in helping behavior in low-harm conditions. A high percentage of female bystanders helped in both low- and high-harm situations, whereas frequent helping by males was observed only when harm to the victim was high. Female victims elicited a significantly greater amount of helping, and sex of thief had no effect. A significant sex of bystander, sex of victim, and harm to victim interaction best describes the data. Results are interpreted in terms of different motivational sets held by males and females when they are responsible for the fate of others. Results also support the utility of an interactionist approach to the question of how individual and situational variables influence prosocial action.     

Sex differences in self-disclosure: a meta-analysis.

A meta-analysis of 205 studies involving 23,702 Ss was conducted to determine whether there are sex differences in self-disclosure. Across these studies, women disclosed slightly more than men (d = .18). This effect size was not homogeneous across studies. Several moderator variables were found. Sex of target and the interaction effect of relationship to target and measure of self-disclosure moderated the effect of sex on self-disclosure. Sex differences in self-disclosure were significantly greater to female and same-sex partners than to opposite-sex or male partners. When the target had a relationship with the discloser (i.e., friend, parent, or spouse), women disclosed more than men regardless of whether self-disclosure was measured by self-report or observation. When the target was a stranger, men reported that they disclosed similarly to women; however, studies using observational measures of self-disclosure found that women disclosed more than men.     

Correlates of age at first sexual intercourse in a national sample of young women

A subsample of 814 sexually experienced adolescent females from the 1979 U.S. National Survey of Young Women was analyzed to assess the correlates of age at 1st sexual intercourse. Multiple regression procedures were used to examine sets of variables sequentially. In the hierarchical regression model, the control variables (respondent's age, race, religion, and age at menarche), along with 3 independent variables (household income, ideal age at 1st marriage, and ideal age for 1st birth), predicted age at 1st intercourse. The control variables accounted for a major portion of the variance in the model. Of the controls, chronological age and age at menarche were highly significant across all models tested.     

Sex differences in romantic attachment: a meta-analysis

This article presents the first meta-analysis of sex differences in the avoidance and anxiety dimensions of adult romantic attachment, based on 113 samples (N = 66,132) from 100 studies employing two-dimensional romantic attachment questionnaires (Experiences in Close Relationships, Experiences in Close Relationships-Revised, and Adult Attachment Questionnaire). Overall, males showed higher avoidance and lower anxiety than females, with substantial between-study heterogeneity. Sex differences were much larger in community samples (bivariate D = .28) than in college samples (D = .12); web-based studies showed the smallest sex differences (D = .07) in the opposite direction. Sex differences also varied across geographic regions (overall Ds = .10 to .34). Sex differences in anxiety peaked in young adulthood, whereas those in avoidance increased through the life course. The relevance of these findings for evolutionary models of romantic attachment is discussed, and possible factors leading to underestimation of sex differences are reviewed.     

The effects of empathic instructions upon donating behavior: Sex differences in young children

First-grade children were given either empathy instructions (in which they were told to imagine themselves in the target person's place) or neutral instructions (in which they were told to listen to what the target person did). For half the subjects, the target person was of the same sex; for the other half, the target person was of the opposite sex. Subjects were then given a chance to anonymously donate money to the target child, who was presented as being in need. Liking for the target child, subject's perceptions of the target child's emotional state, and subjects' report of their own emotional states were also assessed. Empathic instructions increased donating behavior for males, but not for females. Accuracy of perception of the target person's state was generally high. Self-reports of emotional states congruent with that of the target tended to be associated with increased donating behavior only for males, but these self-reports were greater for females than males, and greater for both sexes with same-sex target persons. Liking also was enhanced by gender similarity. These results are discussed in terms of a proposed relationship among empathy, prosocial behavior, sex, and age.We wish to express our gratitude to the staff and students of Wannamaker and North Fairview Elementary Schools of Topeka, Kansas, for their assistance in carrying out this research, and also thank C. Daniel Batson for his helpful suggestions and comments.     

Sex differences in urinary odors produced by young laboratory rats (Rattus norvegicus)

Responses of adult female rats to male and female pup urine were examined in three experiments. Investigatory sniffing of male and female pup urine deposits by maternal rats was compared in a series of simultaneous choice tests given at 3-day intervals between Day 2 and Day 17 postpartum. Male urine was consistently preferred. Introduction of male, but not female, pup urine to the nest was also found to significantly elevate maternal licking of anogenital regions of pups. Thus, urine from pups of various ages contains sex-identifying odors that differentially elicit spontaneous maternal interest. The odor of male urine may provide a sufficient stimulus to account for the greater anogenital licking that males of this species normally receive. Nonmaternal, naive, adult females behaved like maternal rats, preferring male urine in the choice test. This indicates that the maternal condition of a dam is not necessary either for the olfactory discrimination or for the male odor preference.     

Gender differences in psychopathy in a Swedish offender sample

In this study we examined gender differences in the PCL:SV employing a variety of statistical methods with two subsets of psychopathic individuals drawn from larger samples of 129 female and 499 male Swedish offenders. The larger samples included forensic psychiatric patients, forensic psychiatric evaluees and criminal offenders. We found gender differences in antisocial behavior, as defined in factor 2 of the PCL:SV, with female psychopaths (PCL:SV>or=18) displaying significantly more lying, deceitfulness and lack of control, while male psychopaths were more antisocial as measured by the PCL:SV. We conclude that it might be meaningful to use gender specific definitions in the assessment of psychopathy or, alternatively, slightly revise the diagnostic tools. Our results support the use of the three-factor model of the PCL-R and PCL:SV introduced by Cooke and Michie (2001) in female populations.     

Sex differences in the reciprocal relationships between mild and severe corporal punishment and children's internalizing problem behavior in a Chinese sample

The study aimed to investigate the sex differences in the reciprocal relations between parental corporal punishment and child internalizing problem behavior in China. Four hundred fifty-four Chinese elementary school-age children completed measures of their parental corporal punishment toward them and their own internalizing problem behavior at two time points, 6 months apart. Structural equation modeling revealed that both parental mild and severe corporal punishment significantly predicted child internalizing problem behavior for girls, but only parental severe corporal punishment marginally predicted child internalizing problem behavior for boys; child internalizing problem behavior predicted both mild and severe corporal punishment for boys but not for girls. The findings highlight the important role of severity of corporal punishment and child sex in understanding the relations between parental corporal punishment and child internalizing problem behavior and have implications for the intervention efforts aimed at reducing child internalizing symptoms or parental corporal punishment in China.     

Sex differences in verbal fluency: a short note

Adult male and female subjects performed two fluency tasks from the ‘Kit of Reference Tests for Cognitive Factors’. Although both word fluency and ideational fluency are said to show female superiority, a significant difference in favour of females could be found only in the task which primarily requires lexical access and not in the task requiring mental access to colour and form of objects.     

Sex differences in interaction style as a product of perceived sex differences in competence

Males' and females' interaction styles were observed while they worked in four-person, mixed-sex groups on a discussion task. In some groups, members were only given information about each others' names and gender. In this circumstance, men were perceived by themselves and other group members to be higher in competence than women. Further, men engaged in a greater amount of active task behavior than women (e.g., giving information, giving opinions), and women exhibited a greater amount of positive social behavior than men (e.g., agreeing, acting friendly). In other groups, members' competency-based status was manipulated by providing false feedback that they were high or low relative to their group in intellectual and moral aptitude. High status members were then perceived to be more competent than low status ones and, further, high status individuals engaged in more active task and less positive social behavior than low status ones. In this condition, no sex differences were obtained on perceived competence or on active task or positive social behavior. Overall, these findings support the idea that the gender differences obtained in interaction when status was not specified were partially a function of group members' belief that the sexes differ in competence. Direct information concerning members' intellectual and moral competence apparently blocked the perceived gender-to-competence link, and status alone affected perceived competence and interaction style.