Sibling, family environment and ability correlates of adolescents' aspirations: ethnic group differences

Longitudinal data are used to examine relationships between sibling variables and adolescents' aspirations at different social status, family environment, and ability levels in a sample of 260 Anglo-Australian, 120 Greek, and 90 Southern Italian families. In this follow-up study of an earlier investigation, each family has a 16-year-old child and the analyses relate to these adolescents. The study shows that for the sample, sibling variables have modest associations with their educational and occupational aspirations, even after taking into account relationships involving social status, parents' associations, and ability. However, there are also ethnic group variations in the relations between the sibling variables and adolescents' aspirations. In particular, while sibship size tends not to be associated with aspirations within the different ethnic groups, birth order continues to show several significant relationships. The study suggests that there are differential relationships between birth order and educational and occupational aspirations for adolescents from different ethnic groups, even after taking into account the effect on aspirations of measures of ability and family environment.     

Family environment and cognitive correlates of young adults' social status attainment: ethnic group differences

A longitudinal sample of 21-year-old Australians from Anglo-Australian, Greek and Southern Italian families was used to examine relationships of children's cognitive performance, family learning environments, adolescents' perceptions of family learning contexts, and measures of young adults' social status attainment. Generally, the findings using a regression approach indicated that there were ethnic group differences in the relations between parents' academic socialisation, children's cognitive performance, and measures of young adults' social status attainment. The results also showed that in each ethnic group, adolescents' perceptions of parents' support for learning had strong associations with young adults' status attainment.     

Strategy and results: Sex differences in electrographic correlates of verbal and figural creativity

Sex differences in electroencephalographic (EEG) correlates of creativity were studied using verbal and figural divergent tasks to be performed in accordance with the instructions to “give any solution” or “give an original solution.” The common effect was a greater activity of the right hemisphere, which did not depend on the sex, task type, or instructions for performance of the tasks. The α₂ and β₂ rhythms were the main EEG frequency correlates of creative thinking; the degree and sign of their reactivity depended on the aforementioned factors. Although the creative abilities in men and women were similar under test conditions, the EEG correlates of both figural and verbal tasks were sex-dependent. A high reactivity of the α₂ rhythm was more marked during verbal creative thinking in women; and that of the β₂ rhythm, during figural creative thinking in men. The instruction-related improvement of the critical selection of solutions was to a greater extent reflected by changes in the cortical activity, more pronounced in the frontal cortex in the women. Thus, the same creative productivity in men and women was mediated by different strategies of performance of both figural and verbal tasks, and the sex-related differences in these strategies remained even when the motivation for creativity was changed.     

Sex differences in children's free drawings: a study on girls with congenital adrenal hyperplasia

Sex differences are recognized in children's free drawings with respect to motifs, colors, figure compositions, and expression. Boys tend to draw mobile objects and mechanical objects with dark or cold colors and often use bird's-eye-view composition when they draw pictures, whereas girls like to draw human motifs (especially girls and women), flowers, and butterflies with light and warm colors and tend to arrange motifs in a row on the ground. Analyses were made on the drawings of girls with congenital adrenal hyperplasia (CAH) and unaffected boys and girls, using masculine and feminine indexes. Sex difference in masculine and feminine indexes was clear in the drawings by unaffected boys and girls. Their drawings do not or mostly do not contain characteristics typical of the opposite sex. Compared with those of unaffected girls, the pictures of CAH girls more strongly showed masculine characteristics. The feminine index for the pictures of CAH girls was significantly lower than that for unaffected girls, while the masculine index for CAH girls was significantly higher than that for unaffected girls. Furthermore, the masculine index for CAH girls was not significantly different from that of unaffected boys. These results suggest that androgen exposure during fetal life may contribute to shaping masculine characteristics in children's free drawings.     

Sex differences and bilateral electrodermal activity: a replication

The present study was aimed at replicating the results of a previous work on sex differences and electrodermal asymmetry from our laboratory (Román, et al. 1987). Skin conductance was bilaterally recorded in a sample of 44 dextral volunteers (22 males and 22 females) during a stimulus-free period, and the performance of two tasks (verbal and spatial). Subjects were grouped into two groups of right-hand and left-hand dominance in their electrodermal responses (EDRs) in accordance with their laterality coefficient scores at rest. During the tasks subjects appeared clearly differentiated by their lateralization in the magnitude and frequency of EDRs independently of gender: right-hand responders showed higher electrodermal activity on their right hand, while left-hand responders showed higher electrodermal activity on their left hand. Sex differences were not observed within each responsiveness pattern. The orientation of phasic electrodermal changes remained constant throughout the different conditions.     

Sex differences in response to children's toys in nonhuman primates (Cercopithecus aethiops sabaeus)

Sex differences in children's toy preferences are thought by many to arise from gender socialization. However, evidence from patients with endocrine disorders suggests that biological factors during early development (e.g., levels of androgens) are influential. In this study, we found that vervet monkeys (Cercopithecus aethiops sabaeus) show sex differences in toy preferences similar to those documented previously in children. The percent of contact time with toys typically preferred by boys (a car and a ball) was greater in male vervets (n=33) than in female vervets (n=30) (P<.05), whereas the percent of contact time with toys typically preferred by girls (a doll and a pot) was greater in female vervets than in male vervets (P<.01). In contrast, contact time with toys preferred equally by boys and girls (a picture book and a stuffed dog) was comparable in male and female vervets. The results suggest that sexually differentiated object preferences arose early in human evolution, prior to the emergence of a distinct hominid lineage. This implies that sexually dimorphic preferences for features (e.g., color, shape, movement) may have evolved from differential selection pressures based on the different behavioral roles of males and females, and that evolved object feature preferences may contribute to present day sexually dimorphic toy preferences in children.     

Sex differences in telomeres and lifespan

Males and females often age at different rates resulting in longevity 'gender gaps', where one sex outlives the other. Why the sexes have different lifespans is an age-old question, still fiercely debated today. One cellular process related to lifespan, which is known to differ according to sex, is the rate at which the protective telomere chromosome caps are lost. In humans, men have shorter lifespans and greater telomere shortening. This has led to speculation in the medical literature that sex-specific telomere shortening is one cause of sex-specific mortality. However, telomere shortening may be a cause for and/or a consequence of the processes that govern survival, and to infer general principles from single-taxon studies may be misleading. Here, we review recent work on telomeres in a variety of animal taxa, including those with reverse sexual lifespan dimorphism (i.e., where males live longer), to establish whether sex-specific survival is generally associated with sex differences in telomere dynamics. By doing this, we attempt to tease apart the potential underlying causes for sex differences in telomere lengths in humans and highlight targets for future research across all taxa.     

Low-investment copulation: Sex differences in motivations and emotional reactions

Samples of male (n = 113) and female (n = 175) college students were surveyed. Majorities of both sexes agreed with statements indicating that males' sexual attractiveness varied more than females' sexual attractiveness as a function of their status. Subjects who reported more sex partners and a greater aversion to sexual monogamy were slightly more likely to agree that they tested their partners to see how far they could push them. Interviews with highly sexually active females (n = 32) and males (n = 24) indicated that low-investment copulation and lack of control over the sexual access-investment ratio caused even women with very permissive attitudes and multiple sex partners to develop an aversion to low-investment copulation. Three levels were identified in this process. The techniques that women with multiple partners used to deal with their feelings are described. Females tested their partners for ability and willingness to invest. Males tested for opportunities to reduce investment and pursue other women. High status, for example athletic stardom, transformed males' sexual attractiveness to women and numbers of sex partners. Results were consistent with the view that the emotional-motivational mechanisms that moderate sexual arousal and attraction are sexually dimorphic.     

Sex differences in recombination and mapping adaptations

Since the raw material of marker based mapping is recombination, understanding how and why recombination rates evolve, and how we can use variation in these rates will ultimately help to improve map resolution. For example, using this variation could help in discriminating between linkage and pleiotropy when QTL for several traits co-locate. It might also be used to improve QTL mapping algorithms. The goals of this chapter are: (1) to highlight differences in recombination rates between the sexes, (2) describe why we might expect these differences, and (3) explore how sex difference in recombination can be used to improve resolution in QTL mapping.     

Sex differences in drug- and non-drug-induced analgesia

Historically, biomedical research has been conducted almost exclusively with male subjects. A growing number of studies now demonstrate sex differences in analgesia produced both by drugs and by environmental stimuli. This review summarizes the current literature on sex differences in analgesia produced by opioids, cholinergics and other drugs, and by stress, exercise and other environmental manipulations. A brief overview of the physiological mechanisms underlying sex differences in analgesia is provided, as well as suggestions for future research. It is not yet known whether the development of sex-specific analgesia treatment guidelines is warranted.     

Sex differences in adrenocortical structure and function

Summary The cytological aspects of sexual dimorphism in the rat adrenal cortex and its relationship to the gonads have been investigated. The adrenal glands of mature female rats were heavier than those of males, and morphometry showed that this was almost exclusively due to conspicuous differences in the volume of cells of the zona fasciculata (ZF) and zona reticularis (ZR). Stereology demonstrated that the volume of the mitochondrial and lipid droplet compartments, as well as the surface area per cell of mitochondrial cristae and smooth endoplasmic reticulum tubules, were markedly higher in the ZF and ZR cells of female animals. Orchiectomy increased and ovariectomy decreased the adrenal weight, by eliciting hypertrophy and atrophy, respectively, of ZF and ZR cells; these effects of gonadectomy were reversed by the appropriate gonadal hormone replacement. It is suggested that the sexual dimorphism of the rat adrenal cortex may depend upon the inhibitory action of testosterone and the stimulatory effect of estradiol on the hypothalamo-hypophyseal-adrenal axis.     

Sex differences in adrenocortical structure and function

Summary Adrenal glands of adult female rats are heavier than the glands of corresponding male rats. Postpubertal orchiectomy increases the adrenal weight, an effect restored by testosterone replacement. Under the same conditions ovariectomy of 8 weeks duration does not change the adrenal weight while estradiol replacement enhances the relative adrenal weight.Karyometric studies have shown that nuclei in the female zona fasciculata cells are larger (app. 18%) than those of the male. Similar but only slight differences (2%) were observed in the zona reticularis. Orchiectomy results in enlargement of cell nuclei within all zones of the adrenal cortex; testosterone replacement has the opposite effect. Ovariectomy of 8 weeks duration slightly enhances the volume of nuclei of the zona glomerulosa cells, has no effect on the nuclei of the zona fasciculata and reduces the volume of nuclei in the zona reticularis. Estradiol replacement reduces the volume of nuclei of the zona glomerulosa cells but increases nuclear volume in the zona fasciculata and in the zona reticularis.Thus testosterone has an inhibitory effect on the adrenal cortex of the rat while the physiologic effect of estradiol on the morphology of this gland, particularly on the zona fasciculata cells is rather dubious.The author wishes to thank Mrs. B. Westerska and Miss K. Siejak for excellent technical assistance.This research was supported in part by a grant from the Zoological Committee, 2nd Department, Polish Academy of Sciences.This paper is dedicated to the memory of late Kazimierz Mietkiewski, M.D., Ph.D. whose encouragements and suggestions were most stimulating for my work.