Early sex differences in spatial skill.

This study investigated sex differences in young children's spatial skill. The authors developed a spatial transformation task, which showed a substantial male advantage by age 4 years 6 months. The size of this advantage was no more robust for rotation items than for translation items. This finding contrasts with studies of older children and adults, which report that sex differences are largest on mental rotation tasks. Comparable performance of boys and girls on a vocabulary task indicated that the male advantage on the spatial task was not attributable to an overall intellectual advantage of boys in the sample.     

Ontogeny of sex differences in defensive burying behavior in rats: effect of social isolation

The aim of the present experiments was to clarify sex differences in socio-developmental factors that affected defense behavior in rats. Sex differences in the defensive burying behavior of rats, and related social factors, were explored in three developmental stages: juvenile, puberty, and adult; 30, 50, and 80 days of age, respectively. The duration of burying, digging into bedding material, stretch-attend postures, and crouch/freezing were measured in a shock-prod test. For males, the duration of burying was longer in the juvenile and pubertal stages than in adulthood. For females, no age differences in the duration of burying were found. Males showed longer burying durations than females in both the juvenile and pubertal stages. For both sexes, the highest duration of digging was found in the juvenile stage, and females showed longer durations of digging than males. Both male and female rats isolated during the juvenile stage, from 26 to 40 days of age, showed smaller durations of burying behavior compared to pair-reared rats. This effect of juvenile isolation was maintained among both adult males and females even when they were returned to pair rearing after isolation. Isolation during adulthood, from 66 to 80 days of age, increased burying behavior in males, but decreased it in females. The durations of digging, stretch-attend postures, and crouch/freezing were not affected by isolation. The decrease in defensive burying and its increase resulting from isolation in adult male rats, suggest that the emergence of adult-like social relationships in males suppressed the duration of burying. Male and female rats isolated during the juvenile stage maintained lower levels of burying, suggesting that social experience as juveniles is important for the emergence of defensive burying behavior.     

Development of sex differences in spatial memory.

Males typically perform better than females on tests of spatial abilities. However, Silverman and Eals (1992) found that females can surpass males on certain tasks, in particular recall of object location. This study investigated the age at which females begin having greater recall in object location. Recall was tested with object arrays (sets of line drawings of common objects) using samples of 80 adults (M age = 21 yr.) and 139 children at 3 age groups. Adult data replicated earlier findings, indicating significantly greater recall by women. The samples of children at different ages--4 yr. (n = 43), 10-11 yr. (n = 53), and 15-16 yr. (n = 43)--did not show significant sex differences in this type of recall. The findings suggest that females may surpass males in this spatial ability as adults, apparently due to gradual improvements in spatial memory through childhood and adolescence.     

Sex differences in color preferences transcend extreme differences in culture and ecology

At first glance, color preferences might seem to be the most subjective and context-dependent aspects of color cognition. Yet they are not. The present study compares color preferences of women and men from an industrialized and a remote, nonindustrialized culture. In particular, we investigated preferences in observers from Poland and from the Yali in Papua, respectively. Not surprisingly, we found that color preferences clearly differed between the two communities and also between sexes. However, despite the pronounced cultural differences, the way in which men and women differed from each other was almost the same in both cultures. At the same time, this sexual contrast was not specific to biological components of color vision. Our results reveal a pattern of sexual dimorphism that transcends extreme differences in culture and ecology. They point toward strong cross-cultural constraints beyond the biological predispositions of nature and the cultural particularities of nurture.     

Selective sex differences in declarative memory

Sex invariance of a six-factor, higher order model of declarative memory (two second-order factors: episodic and semantic memory; and four first-order factors: recall, recognition, fluency, and knowledge) was established for 1,796 participants (35-85 years). Metric invariance of first- and second-order factor loadings across sex was demonstrated. At the second-order level, a female advantage was observed for both episodic and semantic memory. At the first-order level, sex differences in episodic memory were apparent for both recall and recognition, whereas the differences in semantic memory were driven by a female superiority in fluency. Additional tests of sex differences in three age groups (35-50, 55-65, and 70-85 years of age) indicated that the female superiority in declarative memory diminished with advancing age. The factor-specific sex differences are discussed in relation to sex differences in hippocampal function.     

Individual and sex differences in reminiscence

Inverted alphabet printing, rotary pursuit, and mirror tracking tasks were administered to 84 subjects in order to ascertain (a) reproducibility of reminiscence scores within and between tasks and (b)sex differences in reminiscence. With prerest performance levels held constant by second-order partial correlation procedures, reproducibility of individual reminiscence differences within tasks was significant but quite low, while predictability of reminiscence from one task to another was negligible. The sexes reminisced essentially alike on inverted alphabet printing, but females reminisced more than males on the other tasks, presumably because they were relatively more depressed by massed practice on these tasks. Thus, individual and sex differences were essentially task specific. Implications of results for reminiscence theories and for the credibility of alleged relationships between reminiscence and other organismic variables were discussed.     

Sex differences in the contexts of extreme jealousy

Research on sex differences in jealousy using continuous measures sometimes reveals that women report more intense jealousy than men in response to both sexual and emotional infidelity. Two studies tested whether these findings might have stemmed from sex differences in the interpretation of the upper anchor of the jealousy scales (e.g., “extremely jealous”). In Study 1, women and men offered different types of exemplars when describing situations in which they felt extremely jealous. A significantly greater proportion of women than men reported feeling extreme jealousy in the context of romantic relationships. Additional results demonstrated that women and men confuse the terms “jealousy” and “envy,” although this confusion cannot account for the sex differences in the contexts of extreme jealousy. Study 2 demonstrated that the sex difference in the intensity of reported jealousy disappears if the upper anchor of the scale is modified to include specific contextual information (e.g., “as jealous as you could feel in a romantic relationship”).     

Age-related neural differences in affiliation and isolation

While previous aging studies have focused on particular components of social perception (e.g., theory of mind, self-referencing), little is known about age-related differences specifically for the neural basis of perception of affiliation and isolation. This study investigates age-related similarities and differences in the neural basis of affiliation and isolation. Participants viewed images of affiliation (groups engaged in social interaction) and isolation (lone individuals), as well as nonsocial stimuli (e.g., landscapes), while making pleasantness judgments and undergoing functional neuroimaging (BOLD fMRI). Results indicated age-related similarities in response to affiliation and isolation in recruitment of regions involved in theory of mind and self-referencing (e.g., temporal pole, medial prefrontal cortex). Yet age-related differences also emerged in response to affiliation and isolation in regions implicated in the theory of mind, as well as self-referencing. Specifically, in response to isolation versus affiliation images, older adults showed greater recruitment than did younger adults of the temporal pole, a region that is important for retrieval of personally relevant memories utilized to understand others' mental states. Furthermore, in response to images of affiliation versus isolation, older adults showed greater recruitment than did younger adults of the precuneus, a region implicated in self-referencing. We suggest that age-related divergence in neural activation patterns underlying judgments of scenes depicting isolation versus affiliation may indicate that older adults' theory of mind processes are driven by retrieval of isolation-relevant information. Moreover, older adults' greater recruitment of the precuneus for affiliation versus isolation suggests that the positivity bias for emotional information may extend to social information involving affiliation.     

Handedness and sex differences in hemispheric asymmetry

A study was designed to assess the contributions of the factors of sex and familial history to cerebral dominance, where cerebral dominance was inferred from laterality on a dichotic listening task. The 144 subjects were selected from a larger sample on the basis of handedness, sex, and familial history of sinistrality, and tested on a task involving the dichotic presentation of CV syllables. Analysis of the data indicated that in female subjects, the presence of familial sinistrality increased the likelihood that they present atypical left-ear superiorities, while in males the converse was the case. Moreover, there was a significant sex difference overall, such that males were more clearly lateralized than females. A review of other dichotic listening studies provided support for the reliability of this sex difference for dichotic tasks using verbal material. A review of the clinical literature indicated that the hypothesis of a sex difference is at least tenable and merits further investigation. However, the possibility that there is a sex difference in the cognitive strategy used in dichotic listening cannot be ruled out.     

Influence of sex differences in leaders' behavior

Sex differences in influence tactics were examined with a sample of 269 followers (67 men, 202 women) at a large midwestern national insurance company who rated the downward influence tactics used by their direct supervisors. Downward influence tactics are behaviors used by leaders to gain compliance from followers. One department within the organization was identified as a source for participants in the study. Participation was voluntary. The age range for the sample was 21 to 65 years, with the largest percentage falling in the 40-49 year range (M = 3.8, SD = .8). Hierarchical linear modeling procedures were utilized to analyze the multiple level data (leader and follower) and to examine variables within the organization at different levels of analysis. Leader participants were asked to solicit their followers to complete an influence tactic measure, which consisted of the most reliable subscales taken from the Influence Behavior Questionnaire, Schriesheim and Hinkin Influence Measure, and the Profiles of Organizational Influence Strategies. The integrated measure resulted in a 45-item scale. It was hypothesized that, overall, followers would report that male leaders would use hard influence tactics more frequently than female leaders. On the other hand, followers would report that female leaders would use soft influence tactics more frequently than male leaders. When differentiating followers by sex, however, we expected that male followers would report more than female followers that their leaders use hard tactics more frequently. Also, we expected that female followers would report (more than male followers) that their leaders use soft tactics more frequently. Overall, followers reported that male leaders used significantly more personal appeal and consultation, so called "soft tactics," with their followers than did female leaders. Female followers reported that their leaders (both male and female) used consultation and inspirational appeal more frequently. In contrast, male followers reported that their leaders used exchange, so called "hard tactics," more frequently.     

Perceived sex differences in managerially relevant characteristics

A national sample of 884 male managers completed a survey of managerially relevant perceived sex differences. Females were rated lower on the following scales: (a) aptitudes, skills, and knowledge; (b) motivation and job interest; (c) temperament; and (d) work habits and attitudes. Moreover, lower ratings of women were prevalent among males in a variety of jobs, organizations, and industries.     

Cultural and sex differences in touch avoidance

250 male and female respondents from American, Mediterranean, Near Eastern, and Far Eastern cultures completed a self-report measure of touch-avoidance. Confirmatory factor analysis indicated factors for opposite-sex and same-sex touch-avoidance. These factors were used as dependent variables in a 4 x 2 (culture by sex) multivariate analysis of variance which yielded a significant interaction of culture by sex on opposite-sex touch-avoidance and a main effect of the respondents' sex on same-sex touch-avoidance.     

Children's stereotypes about sex differences in emotionality

In spite of the egalitarian atmosphere of recent years, contemporary preschool children possess pronounced stereotypes about sex differences in emotionality. They associate anger with maleness, but associate happiness, sadness, and fear with femaleness. These stereotypes are similar to those held by adults, but are largely dissimilar to actual sex differences in emotionality. The impact and possible etiology of these stereotypes are discussed.     

Early sex differences in weighting geometric cues

When geometric and non-geometric information are both available for specifying location, men have been shown to rely more heavily on geometry compared to women. To shed insight on the nature and developmental origins of this sex difference, we examined how 18- to 24-month-olds represented the geometry of a surrounding (rectangular) space when direct non-geometric information (i.e. a beacon) was also available for localizing a hidden object. Children were tested on a disorientation task with multiple phases. Across experiments, boys relied more heavily than girls on geometry to guide localization, as indicated by their errors during the initial phase of the task, and by their search choices following transformations that left only geometry available, or that, under limited conditions, created a conflict between beacon and geometry. Analyses of search times suggested that girls, like boys, had encoded geometry, and testing in a square space ruled out explanations concerned with motivational and methodological variables. Taken together, the findings provide evidence for an early sex difference in the weighting of geometry. This sex difference, we suggest, reflects subtle variation in how boys and girls approach the problem of combining multiple sources of location information.     

Age and sex differences in behaviors mediated by the ventromedial hypothalamus.

Age and sex differences in behaviors mediated by the ventromedial hypothalamus (VMH) were examined in the rat. Circadian rhythm, emotionality, and taste responsiveness (except for responsiveness to quinine adulteration) were found to shift, in one or both sexes, toward a pattern suggesting decreased VMH functioning with increasing age. A post hoc analysis of the configuration of positive and negative results suggests that, for those behaviors known to show both immediate and sustained effects of VMH lesion, male rats show a marked trend toward the lesioned pattern of behavior with increasing age, whereas females show weaker or nonexistent age trends in the same behaviors. For those behaviors that have been shown to change only during the static, obese phase, or for which data re controversial as to whether changes take place as a result of the VMH lesion at all, this age and sex pattern does not emerge.