What is the role of mothers in the acquisition of termite-fishing behaviors in wild chimpanzees (Pan troglodytes schweinfurthii)?

This paper explores the role of maternal influences on the acquisition of a tool-using task in wild chimpanzees (Pan troglodytes schweinfurthii) in order to build on and complement previous work done in captivity. Young chimpanzees show a long period of offspring dependency on mothers and it is during this period that offspring learn several important skills, especially how to and on what to forage. At Gombe National Park, one skill that is acquired during dependency is termite-fishing, a complex behavior that involves inserting a tool made from the surrounding vegetation into a termite mound and extracting the termites that attack and cling to the tool. All chimpanzees observed at Gombe have acquired the termite-fishing skill by the age of 5.5 years. Since the mother is the primary source of information throughout this time period, I investigated the influence of mothers' individual termite-fishing characteristics on their offsprings' speed of acquisition and proficiency at the skill once acquired. Mother's time spent alone or with maternal family members, which is highly correlated to time spent termite-fishing, was positively correlated to offspring's acquisition of critical elements of the skill. I also investigated the specific types of social interactions that occur between mothers and offspring at the termite mound and found that mothers are highly tolerant to offspring, even when the behavior of the offspring may disrupt the termite-fishing attempt. However, no active facilitation by mothers of offsprings' attempts were observed. Electronic Supplementary Material Electronic supplementary material Supplementary material is available for this article at http://dx.doi.org/10.1007/s10071-005-0002-7 and accessible for authorised users.     

Sexual Debut Ages in Heterosexual,Lesbian, Gay,and Bisexual Young Adults in Norway

This study estimates sexual debut ages in young heterosexual, lesbian, gay, and bisexual men and women in Norway. A questionnaire survey was completed online by 27.2 % of a representative national web sample of 2090 persons aged 18–29 years. Three self-selected samples of 924 respondents completed an extended version of the survey online. Lesbian and bisexual women reported earlier experience of orgasm through masturbation than heterosexual women (median 13.1 vs. 15.2 years), and heterosexual men (median 13.5) reported earlier debut than heterosexual women. There was a statistically significant difference between heterosexual and lesbian and bisexual women’s age at the first experience of receptive vaginal sex (median 16.8 vs. 15.4 years). As regards experience of insertive vaginal sex, a significantly higher percentage of heterosexual men than women, and of heterosexual and lesbian and bisexual women, reported experience. It was more common among lesbian and bisexual women than heterosexual women to have had oral sex with another woman, but in neither group did the cumulative percent reach 50 % by the age of 29 years and the median could not be estimated. Gay and bisexual men reported earlier receptive anal sex debut than heterosexual men. With regard to insertive anal sex, gay and bisexual men accumulated experience earlier than heterosexual men, and lesbian and bisexual women acquired this experience earlier than heterosexual women. Compared to heterosexuals, LGB persons of both genders engage in more varied sexual activities. Lesbian and gay persons have same-sex experiences at an earlier age than bisexuals.     

Altered states of consciousness are related to higher sexual responsiveness

Altered states of consciousness lead to profound changes in the sense of self, time and space. We assessed how these changes were related to sexual responsiveness during sex. 116 subjects reported (a) intensity of awareness concerning body, space and time, and (b) satisfaction, desire, arousal, and orgasm occurrence. We differentiated vaginal intercourse orgasm from noncoital orgasm. Female vaginal intercourse orgasm was further differentiated as with or without concurrent clitoral masturbation. Overall, sexual responsiveness was related to greater body awareness and lesser time and space awareness. Satisfaction, desire, and arousal were especially associated with less time awareness in women. Female orgasms during vaginal intercourse were related to greater body awareness and lesser time awareness, but noncoital orgasms were unrelated. Our findings provide empirical support for the hypotheses that altered states of consciousness with attentional absorption are strongly related to sexual responsiveness in women, and to a lesser extent in men.     

Juvenile offspring of rats exposed to restraint stress in late gestation have impaired cognitive performance and dysregulated progestogen formation

Gestational stress may have lasting effects on the physical and neurocognitive development of offspring. The mechanisms that may underlie these effects are of interest. Progesterone and its 5α-reduced metabolites, dihydroprogesterone and 5α-pregnan-3α-ol-20-one (3α,5α-THP), maintain pregnancy, have neurotrophic effects, and can enhance cognitive performance. We hypothesized that some of the deleterious effects of gestational stress on the cognitive performance of offspring may be related to progestogen formation. Pregnant rat dams were exposed to restraint under a bright light (thrice daily for 45 min) on gestational days 17-21 or were minimally handled controls. Dams that were exposed to restraint had lower circulating levels of 3α,5α-THP and significantly greater concentrations of corticosterone at the time of birth than did control dams. Male and female offspring, that were gestationally stressed or not, were cross-fostered to non-manipulated dams. Between postnatal days 28-30, offspring were assessed for object recognition, a prefrontal cortex (PFC)-dependent cognitive task. Restraint-exposed offspring performed more poorly in the object recognition task than did control offspring, irrespective of sex. As well, progesterone turnover to its 5α-reduced metabolites in the medial PFC (but not the diencephalon) was significantly reduced among restraint-exposed, compared to control, offspring. Progesterone turnover, and levels of 3α,5α-THP, positively correlated with performance in the object recognition task. Thus, restraint stress in late pregnancy impaired cognitive development and dysregulated progestogen formation in brain.     

Maternal Prenatal Stress and Other Developmental Risk Factors for Adolescent Depression: Spotlight on Sex Differences

Maternal stress during pregnancy has been linked to premorbid abnormalities associated with depression (e.g., difficult temperament, cognitive deficits) in offspring. However, few studies have looked across developmental periods to examine maternal stress during pregnancy and offspring depression during adolescence and whether these associations differ by sex. The current study used data from 1711 mother-offspring dyads (offspring sex: 49.8% male) in a longitudinal birth cohort study. Maternal narratives collected during pregnancy were qualitatively coded for stress-related themes by independent raters. Latent class analysis (LCA) identified distinct subgroups of offspring based on exposure to maternal prenatal stress and other developmental factors from the prenatal, childhood, and adolescent periods that have been associated with depression and/or maternal prenatal stress. LCA identified subgroups that were compared to determine whether and to what extent they differed on adolescent depressive symptoms. LCA revealed a subgroup of “high-risk” individuals, characterized by maternal factors during pregnancy (higher ambivalence/negativity and lower positivity towards the pregnancy, higher levels of hassles, lower maternal education and higher maternal age at birth, higher pre-pregnancy BMI) and offspring developmental factors (decreased cognitive functioning during childhood and adolescence, lower perceived parental support during adolescence, and higher levels of maternal depression during adolescence). High-risk females exhibited elevated conduct symptoms and higher birth order, while high-risk males exhibited decreased internalizing symptoms and lower birth order. Both high-risk males and females reported elevated depressive symptoms during adolescence relative to their “low-risk” counterparts.     

Psychological and socio-demographic variables associated with sexual risk behavior for sexually transmitted infections/HIV

New diagnoses of sexually transmitted infections (STIs) and HIV are rising in the adult population. The main objective of this study was to analyze whether knowledge of STIs/HIV, worry about STIs/HIV and pregnancy, and self-efficacy to refuse sex are predictors of sexual risk behaviors among Spanish young and adults. The study sample was composed of 1,106 young and adults of both sexes aged between 17 and 55 years. Results showed that being single, homosexual, having been tested for HIV, having previously contracted an STI, having a college education and earning a monthly income of €900 or more were the characteristics associated with higher scores in knowledge of STIs/HIV. Self-efficacy to refuse sex predicted most vaginal and anal sexual behaviors (i.e., age at vaginal and anal sex initiation and the number of couples that have remained vaginal sex). We also found that participants with greater knowledge of STIs/HIV reported older age at vaginal sex initiation and higher condom use in the first vaginal sexual contact. We consider that these findings can be useful for the development of STI/HIV prevention programs.     

Paternal Psychiatric Symptoms and Maladaptive Paternal Behavior in the Home During the Child Rearing Years

Data from the Children in the Community Study, a community-based longitudinal study were used to investigate associations between paternal psychiatric disorders and child-rearing behaviors. Paternal psychiatric symptoms and behavior in the home were assessed among 782 families during the childhood and adolescence of the offspring. Paternal anxiety, disruptive, mood, personality, and substance use disorders were independently associated with specific types of maladaptive paternal behavior in the home during the child-rearing years after paternal age, education, income, co-occurring paternal psychiatric symptoms, offspring age, sex, intelligence, temperament, and psychiatric symptoms were controlled statistically. Paternal psychiatric disorders that were present by mean offspring age 14 were associated with elevated risk for maladaptive paternal behavior in the home at mean age offspring 16, after prior maladaptive paternal behavior was controlled statistically. These findings suggest that paternal psychiatric disorder may be an important determinant of maladaptive paternal behavior in the home during the child-rearing years. Improved recognition and treatment of paternal psychiatric disorders may help to reduce the amount of maladaptive parenting behavior that many children and adolescents might otherwise be likely to experience.     

Auditory and visual reaction time in adults during long performance

Better to understand the relation of auditory to visual reaction time (RT) tasks during a long period (320 min.) as well as the evolution of these performances along time, 24 subjects were tested. RT tasks were delivered at 10-min. intervals for 320 min. Correlations between auditory and visual RTs and cross-correlation functions were calculated. Our results confirmed their association, which was maintained throughout the experiment. There were no significant differences in the mean RT by sex or time of day; however, differences were found for the trend slope between type of stimulus and sex.     

Feelings Matter: Depression Severity and Emotion Regulation in HIV/STI Risk-Related Sexual Behaviors

Human immunodeficiency virus (HIV)/sexually transmitted infection (STI) prevention models may not address psychological complexities among adolescents with mental illnesses. This study examined contextual factors related to HIV/STI risk among heterosexually active Black adolescents with mental illnesses to inform the development of targeted HIV/STI prevention strategies. Black adolescent males and females (aged 14–17) were recruited from outpatient mental health programs in Philadelphia, PA to complete a computer-assisted personalized interview on sociodemographics, sexual behaviors, and emotion regulation (N?=?53). Two sample t-tests, Wilcoxon Rank Sum tests and regression modeling were used to examine differences in the study measures by gender and relationship status. Reports of sexual partner concurrency were high—both while already in a sexual relationship (67.3%) and multiple sexual partners in the same day (42.3%). Boys reported significantly more risk behaviors than girls. Sadness dysregulation predicted currently being in a relationship, older age at first oral sex, fewer vaginal sexual partners and fewer unprotected oral sexual encounters. Coping difficulties predicted a greater number of vaginal and oral sexual partners, and a lower age at first vaginal sex. Increasing depression severity was related to older age at first vaginal sex, fewer vaginal sexual partners and fewer unprotected oral sexual encounters in the past 3 months. This formative work suggests that coping mechanisms should be addressed in HIV/STI prevention research through the inclusion of activities targeted toward emotion regulation and decreasing sexual risk behaviors. Psycho-education and skills building may mitigate the psychopathology that contributes to HIV/STI risk in the target demographic.     

Preference for Sex of Child Among Primiparous Women

Primiparous American women (N = 140) were questioned during their third trimester concerning their choice of sex of offspring and their willingness to use sex preselection techniques (if available). Eighty-two women expressed no preference for sex of offspring; of the remaining 58, 33 chose girls and 25 chose boys. Of the 26 women who indicated they would have used preselection technology, 13 chose boys and 13 chose girls. Fifty-three percent of the sample indicated they would not have used preselection techniques; 29% were undecided. These results were at variance with earlier studies that indicated a consistent choice of male firstborns, especially in nonpregnant samples. The discrepancy is discussed in terms of a move from boy preference to no preference and a gradual weakening of societal bias against women.     

Media exposure and language for toddlers from low-income homes

In the current study, we examined whether the quantity of toddlers’ exposure to media was related to language skills and whether meeting the American Association of Pediatrics (AAP) recommendations of limiting media exposure to one hour or less per day was related to language skills. We examined these associations in a sample of toddlers (N = 157) living in low-income homes. Toddlers were about two years of age (M = 28.44 months, SD = 1.48 months) during the first visit when parents reported on toddlers’ exposure to media in the home. Toddlers were about three years of age (M = 33.61 months, SD = 1.06 months) during the second visit when direct measures of toddlers’ expressive and receptive language and receptive vocabulary skills were completed. Controls were child gender, race, mothers’ education, marital status, work status, and center-based child care. Results indicated that more frequent exposure to media was related to lower expressive language, but not receptive language or receptive vocabulary. The predictor of AAP recommendation was not significantly related to any child language outcomes. These results suggest that media exposure may be related to the displacement of language-enhancing activities during a critical time for toddlers’ language development. However, the AAP media recommendation of one hour may not be related to language development.     

Social influences on ant-dipping acquisition in the wild chimpanzees (Pan troglodytes verus) of Bossou,Guinea, West Africa

We currently have little understanding of the influence of learning opportunity, whether social or environmental, and maternal role on tool-use acquisition in young wild chimpanzees. This study aims to fill this gap by focusing on the acquisition of ant-dipping among chimpanzees of Bossou, Guinea. Ant-dipping is a hazardous tool-use behaviour aimed at army ants (Dorylus spp.). Bossou chimpanzees target these ants both at nests (high risk) and trails (low risk) and employ two techniques to consume them: direct mouthing and pull-through. We present data for 13 mother–offspring pairs (1–10 years old). Mothers with young ≤5 years old dipped significantly more often at trails than at nests, thus minimizing the risk posed to themselves and their young. Infants thus benefited from better conditions to observe and practice ant-dipping. Mothers also varied greatly in their percent time spent ant-dipping and offspring differed in their learning opportunity. Our results suggest that high opportunity young started to observe and perform ant-dipping sooner and were better at ant-dipping than low opportunity young. Although mothers and weaned offspring correlated positively in their percent time spent dipping and proficiency, they did not match in technique used or tool length. Finally, we propose that the learning trajectory of young may predict individual and sex differences in adulthood. This study demonstrates the important role of mothers and learning opportunity in the acquisition of a hazardous tool-use behaviour and suggests that chimpanzee material culture is a product of a complex interaction between social processes and ecological factors.     

Sex differences in the adolescent brain

Adolescence is a time of increased divergence between males and females in physical characteristics, behavior, and risk for psychopathology. Here we will review data regarding sex differences in brain structure and function during this period of the lifespan. The most consistent sex difference in brain morphometry is the 9–12% larger brain size that has been reported in males. Individual brain regions that have most consistently been reported as different in males and females include the basal ganglia, hippocampus, and amygdala. Diffusion tensor imaging and magnetization transfer imaging studies have also shown sex differences in white matter development during adolescence. Functional imaging studies have shown different patterns of activation without differences in performance, suggesting male and female brains may use slightly different strategies for achieving similar cognitive abilities. Longitudinal studies have shown sex differences in the trajectory of brain development, with females reaching peak values of brain volumes earlier than males. Although compelling, these sex differences are present as group averages and should not be taken as indicative of relative capacities of males or females.     

大学生性别角色调查研究

目的:探讨不同性别比例的高校大学生的性别角色分布等相关情况。方法:2007年10月份,汉市两所性别比例不同的高校分层随机抽取了大学生共计1451人,采用钱铭怡等人编制的大学性角色量表(CSRI)进行问卷调查。结果:(1)大学生性别角色存在显著的性别差异。(2)大学期间是性别角色发展的重要时期,大学生具有传统性别角色的发展趋势,其中女生的性别角色化明显而男生的性别角色发展相对平稳。(3)性别角色存在显著的专业差异。(4)性别比例不的高校其性别角色没有显著的差异。     

Effects of daily and acute restraint stress during lactation on maternal aggression and behavior in mice

A decreased reactivity to stressors during lactation might heighten the expression of maternal care (including defense of offspring) by minimizing the extent to which stress can impact maternal care. Although stressors applied during pregnancy have variable effects on maternal aggression (or defense of offspring), to date no study has examined the effects of stress applied during the postpartum period on maternal aggression. In this study, we examined the effects of both daily and acute restraint stress (30 min) applied postpartum on maternal aggression and other maternal behaviors. Daily restraint (ending 2 h before testing) did not alter any measure of maternal behavior, including nursing, licking and grooming of pups and pup retrieval, or any measure of maternal aggression. In contrast, acute stress significantly impaired total time aggressive and number of attacks, but pup retrieval was normal. c-Fos levels were significantly elevated in a number of brain regions in association with acute stress, including lateral septum (LS), caudal periaqueductal gray and medial amygdala (MeA), suggesting possible sites where stress reactivity could alter aggression. Together, the results indicate that acute restraint stress impairs maternal aggression and provide a starting point for future studies examining how stress reactivity pathways may intersect with maternal aggression pathways.     

Sex differences in prenatally programmed anxiety behaviour in rats: differential corticotropin-releasing hormone receptor mRNA expression in the amygdaloid complex

We recently reported that male, but not female, offspring born to mothers exposed to social stress during late gestation show heightened anxiety-type behaviour in adulthood. The amygdala organises anxious behaviour, which involves actions of corticotropin-releasing hormone (CRH). CRH gene expression and/or its release are increased in the amygdala in prenatally stressed (PNS) rats. CRH type 1 receptor (CRH-R1) mediates actions of CRH and urocortin I to promote anxiety-like behaviour, whereas the CRH type 2 receptor (CRH-R2) may mediate anxiolytic actions, through actions of urocortins 2 and 3. Here, using quantitative in situ hybridisation, we investigated whether altered CRH receptor mRNA expression in the amygdaloid nuclei may explain the sex differences in anxiety behaviour in adult male and female PNS rats. CRH-R1 mRNA expression was significantly greater in the central amygdala and basolateral amygdala (BLA) in male PNS rats compared with controls, with no change in the basomedial amygdala (BMA) or medial amygdala (MeA). In PNS females, CRH-R1 mRNA expression was greater than controls only in the MeA. Conversely, CRH-R2 mRNA expression was significantly lower in the BMA of male PNS rats compared with controls, but greater in female PNS rats, with no change in the BLA or MeA in either sex. The ratio of CRH-R1:CRH-R2 mRNA in the amygdaloid nuclei was generally increased in PNS males, but not in the PNS females. In conclusion, sex differences in anxiety-type behaviour in PNS rats may be explained by differential mRNA expression for CRH-R1 (pro-anxiogenic) and CRH-R2 (pro-anxiolytic) in the amygdaloid complex.     

Sex ratio and mate preferences: a cross‐cultural investigation

Sex ratio is the number of men per 100 reproductive‐age women within a specified mating pool. We generated and tested two hypotheses about the cross‐cultural relationships between sex ratio and mate preferences using preference ratings of 18 characteristics provided by 9809 participants and corresponding sex ratio data secured from an international organization. The Classical Sex Ratio Mate Preference Shifts Hypothesis predicts that in imbalanced sex ratio societies, the more numerous sex will lower their standards, to facilitate acquisition of a partner of the less numerous sex. The Alternative Sex Ratio Mate Preference Shifts Hypothesis predicts that in lower sex ratio societies, men will lower their standards to secure more short‐term matings, whereas women will raise their standards to avoid deception by men seeking short‐term relationships. Results supported the Classical Sex Ratio Mate Preference Shifts Hypothesis for men, and the Alternative Sex Ratio Mate Preference Shifts Hypothesis for women. Discussion addresses limitations of the current research and highlights future directions for research on the relationships between sex ratio and mating psychology and behavior. Copyright © 2006 John Wiley & Sons, Ltd.     

The evolution of human mating: trade-offs and strategic pluralism

During human evolutionary history, there were "trade-offs" between expending time and energy on child-rearing and mating, so both men and women evolved conditional mating strategies guided by cues signaling the circumstances. Many short-term matings might be successful for some men; others might try to find and keep a single mate, investing their effort in rearing her offspring. Recent evidence suggests that men with features signaling genetic benefits to offspring should be preferred by women as short-term mates, but there are trade-offs between a mate's genetic fitness and his willingness to help in child-rearing. It is these circumstances and the cues that signal them that underlie the variation in short- and long-term mating strategies between and within the sexes.     

Associations Between Maternal Mental Health and Child Emotional and Behavioral Problems: Does Prenatal Mental Health Matter?

This study examined associations between elevated symptoms of prenatal depression or anxiety and offspring emotional and behavioral problems during mid to late childhood taking into account the impact of later maternal mental health symptoms. The sample consisted of 2,891 women and their children (49 % male) from a prospective, community-based study, the Avon Longitudinal Study of Parents and Children. Women completed measures of depressive (Edinburgh Postnatal Depression Scale) and anxious (Crown Crisp Experiential Index) symptoms at regular intervals beginning in pregnancy. Mothers and teachers assessed offspring emotional and behavioral problems using the Strengths and Difficulties Questionnaire when children were 10–11 years old. Multivariable regression models were fit to address study hypotheses. Exposure to elevated symptoms of maternal depression during pregnancy was associated with increased total offspring emotional and behavioral problems, even after controlling for later maternal mental health problems and a range of sociodemographic and psychosocial characteristics, according to mothers’ but not teachers’ reports. Similarly, children exposed to elevated symptoms of maternal anxiety during pregnancy were reported to have increased total emotional and behavioral problems by mothers but not by teachers. We found support for modest associations between elevated symptoms of maternal depression and anxiety during the prenatal period and certain domains of offspring emotional and behavioral problems in mid to late childhood above and beyond the impact of later maternal mental health problems. These findings highlight the need for additional clinical and research attention to the prenatal period and to both maternal depression and anxiety.     

Preliminary efficacy of a computer-based HIV intervention for African-American women

This study evaluated the preliminary efficacy of a computer-based HIV intervention to enhance HIV-protective sexual behaviours, based on a randomised controlled trial among 135 African-American women, 21-29 years of age, seeking services at Planned Parenthood in Atlanta, GA. Participants were randomised either to a control session two, 60-minute computer-based HIV intervention sessions administered on a laptop computer that each concluded with a 15-minute small group session or to a control session of general health information including discussion on HIV prevention. Relative to controls, participants in the computer-based HIV intervention were more knowledgeable about HIV/STD prevention and reported higher scores on the measure of condom use self-efficacy at 3 months post-intervention; they also reported a higher percentage of condom-protected sex and were more likely to use condoms consistently for vaginal sex (odds ratio, OR = 5.9; p < 0.039) and were more likely to use condoms consistently for oral sex (OR = 13.83; p < 0.037). This relatively brief intervention provides preliminary support that an evidence-based group-based HIV prevention intervention for young African-American women can be adapted to a computer-based HIV intervention.