Timing of pubertal maturation and heterosexual behavior among Hong Kong Chinese adolescents

Father absence and pubertal timing in Korean boys and girls

Background and objectives

Pubertal timing is a key life history trait with long-term health consequences in both sexes. Evolutionary theory has guided extensive research on developmental influences, in particular growing up without a father, on earlier menarche. Far less is known whether a similar relationship exists for boys, especially beyond western contexts. We used longitudinal data from the nationally representative sample of Korean adolescents, which provided us with a unique opportunity for studying male puberty using a hitherto underutilized biomarker: age at first nocturnal ejaculation.

Methodology

We pre-registered and tested a prediction that growing up in father-absent households is associated with earlier puberty in both sexes. Large sample size (>6000) allowed testing the effect of father absence, which remains relatively uncommon in Korea, while adjusting for potential confounders using Cox proportional-hazard models.

Results

Self-reported age at first nocturnal ejaculation was on average 13.8 years, falling within the range known from other societies. Unlike previous findings mostly for white girls, we did not find evidence that Korean girls in father-absent households had a younger age at menarche. Boys in father-absent households reported having their first nocturnal ejaculation 3 months earlier on average, and the difference was evident before age 14.

Conclusion and implications

The association between father absence and pubertal timing appears sex- and age-dependent, and these differences may further interact with cultural norms regarding gender roles. Our study also highlights the utility of the recalled age of first ejaculation for male puberty research, which has lagged in both evolutionary biology and medicine.

Exposure to Pornographic Content Among Indian Adolescents and Young Adults and Its Associated Risks: Evidence from UDAYA Survey in Bihar and Uttar Pradesh

Adolescence is period characterized by sexual development, increasing romantic relationships, and the initiation of sexual activity. To enhance the exploration of their sexuality, adolescents may look into sexual resources such as pornography. There has been little research in India to understand how much adolescents are exposed to Internet pornography and what are the associated risk factors. This study examined the level of exposure to pornography among adolescents and the associated factors which determine the exposure to pornography in Uttar Pradesh and Bihar. Understanding the Lives of Adolescents and Young Adults (UDAYA) survey data collected in 2015-2016 was used for this study. The study was based on 3885 adolescent boys and 7766 adolescent girls aged 15-19 years. The mean age for adolescent boys was 16.66 years (SD: 1.3), and for girls it was 16.67 years (SD: 1.3). About 47% of adolescent boys but only 6% of girls were exposed to pornography. The likelihood of exposure to pornography was 1.69 times and 2.27 times more likely among adolescents and girls who had their own personal mobile phones, respectively, compared to those who did not have their own personal mobile phones. The odds of exposure to pornography were significantly higher among adolescent boys who had frequent media exposure than those who had no/rare exposure. Programs on life skills and comprehensive sexuality education need to be prioritize.

First Adolescent Romantic and Sexual Experiences in Individuals With Differences of Sex Development/Intersex Conditions

PURPOSE

Adolescence is an important period for sexual development, including sexual debut. The purpose of this study was to assess first romantic and sexual experiences and debut age in individuals with differences of sex development (DSD/intersex) and compare these with age-matched and gender-matched population control values.

METHODS

Questionnaire data on sociodemographic characteristics, romantic and sexual milestones (e.g., masturbation, dating), satisfaction with sexual life and sexual activity at follow-up, self-esteem, and feelings of femininity or masculinity were collected from 976 participants in Europe with a DSD condition. Participants were divided into six diagnostic subgroups based on their diagnostic classification: women with Turner syndrome, congenital adrenal hyperplasia, 46XY-DSD nonvirilized, and 46XY-DSD female partially virilized conditions and men with 46XY-DSD male or Klinefelter syndrome. Age-specific and gender-specific reference values were retrieved from a Dutch population sample.

RESULTS

Individuals with DSD were less likely to reach each of the romantic and sexual milestones compared to their peers without these conditions and they were significantly older when reaching these milestones. Between clinical subgroups, individuals with Klinefelter were significantly older when reaching milestones and in the female groups and individuals with Turner were the least likely to reach milestones. Furthermore, a higher age when reaching several romantic and sexual milestones was correlated with lower self-esteem, lower satisfaction with sexual life, and lower sexual frequency at follow-up.

DISCUSSION

Due to a difference in biopsychosocial context, individuals with DSD often experience a different and/or delayed sexual development during adolescence. Healthcare providers should be aware of these differences in adolescents with DSD and their sexual development to optimize affirmative counseling.

Pornography Use Profiles and the Emergence of Sexual Behaviors in Adolescence

This research longitudinally explored adolescent pornography (porn) consumption and its association with sexual development in early and middle adolescence. A four-wave design with half-year intervals investigated pornography consumption and different (sexual) activities, such as masturbation, French kissing, petting, giving/receiving manual and oral sex, and intercourse, among 630 respondents (47.9% female, mean age 13.7 years; SD = 0.48) years at T1). A latent growth mixture analysis of pornography consumption revealed two groups with relatively low pornography (LP; 51.8% of the boys, 91.4% of the girls) versus high pornography (HP; 48.2% of the boys; 8.6% of the girls) consumption across time. At T1, HP boys on average watched pornography less than once a month, but more than once a year at T1. At T4, their average pornography use had increased to almost one to two times a week. LP boys never watched pornography at T1. At T4, their average pornography use was still less than once a year. At T1, HP girls never watched pornography, but consumption increased to almost one to three times a month at T4. Across waves of the study, LP girls (almost) never watched pornography. A discrete-time survival mixture analysis of sexual developmental patterning indicated that, compared to their LP peers, both girls and boys in the HP groups showed accelerated development of masturbation, petting, and receiving manual sex. Girls in the HP group were also more inclined to receive oral sex, whereas boys in the HP group also showed earlier and more frequent manual sex and intercourse. Thus, whereas the HP group of boys was substantially larger compared to that of girls, pornography consumption was related to accelerated development of sexual activities for both genders across early and middle adolescence. The discussion deliberates on pornography as a driving force in adolescent sexual development versus pornography as a medium of choice for sexually advanced adolescents.

Adolescent Sexual Behavior Patterns, Mental Health, and Early Life Adversities in a British Birth Cohort

This study tested adolescent sexual behavior patterns at age 14, their association with mental health at age 17 (psychological well-being, substance use, and self-harm attempts), and the influence of early life adversities upon this association. A British birth cohort (5,593 boys and 5,724 girls from the Millennium Cohort Study) was used. Latent class analysis suggested five subgroups of adolescent sexual behaviors: a "no sexual behavior" (50.74%), a "kisser" (39.92%), a "touching under clothes" (4.71%), a "genital touching" (2.64%), and an "all sexual activities" class (1.99%). Adolescents from the "kisser," "touching under clothes," "genital touching," and "all sexual activities" classes reported significantly more substance use and self-harm attempts compared to adolescents from the "no sexual behavior" group. The associations became weaker after controlling for early life adversities (reducing around 4.38% to 37.35% for boys, and 9.29% to 52.56% for girls), and reduced to a smaller degree after further controlling for mental health variables at 14. The associations between sexual behaviors and psychological well-being became non-significant after controlling for early life adversities. Adolescents who have engaged in low-intensity sexual activities at early age may have poorer reported mental health, a pattern that is stronger for girls and early life adversity may partially explain this association.

The pattern of romantic and sexual related experiences among Chinese young adolescents: an exploration with multi-group latent class analysis

Background

Studies on very young adolescents’ romantic and sexual experiences would help inform the context in which early sex arises. However, such studies are scant in China due to sparse data and cultural issues.

Method

This study used the GEAS baseline data conducted among1776 adolescents in Shanghai. Multi-group latent class analysis was used to explore adolescents’ romantic and sexual experiences patterns and subgroups. Multi-nominal logistic regression was performed to identify the factors distinguishing different subgroups subsequently.

Results

There were gender differences in the lifetime prevalence for very young adolescents’ romantic and sexual-related behaviors. The Multi-group latent class analysis indicated that the participants could be classified into three classes: general group, early romance group, and sex exploratory group. Multi-nominal logistic regression showed youth in the early romance group were more likely to had friends of both gender, ever had a romantic relationship, and had more autonomy in deciding where to go than the general group; while male respondents in the sex exploratory group were older, ever had a romantic relationship, believed that boys should be more sexually active and more proactive than girls, had more autonomy on deciding where to go, and perceived less school connection and neighborhood cohesion. Female respondents in the sex exploratory group were older and less empowered in decision-making than the general group.

Conclusions

The result provides a picture of romantic and sexual behavior patterns among both gender of very young adolescents in China. Current sex education needs not only to be culturally appropriate but also to address the harm of gender inequality and stereotypes, as well as to provide accessible and supportive services to help young adolescents personalize their received information and strengthen their skills in communication, decision making, and critical thinking.

Studies on teenagers' romantic and sexual experiences would help to prevent early sex arises before it really takes place. However, such studies are limited, especially in China. The traditional culture thought that youth should not start romance before college. This study used the Global Early Adolescent Study Shanghai site baseline data collected among1776 teenagers to explore their romantic and sexual experiences patterns and identify the influencing factors. There were significant gender differences in teenagers’ romantic and sexual-related behaviors. According to the multi-group latent class analysis, we classified the teenagers into three classes: the general group, the early romance group, and the sex exploratory group. The multi-nominal logistic regression showed youth in the early romance group were more likely to had friends of both boys and girls, ever had boyfriend/girlfriend and were freer to go out than the general group; while boys in the sex exploratorygroup were older, ever had a boyfriend/girlfriend, believed it was normal for boys to be sexually active than girls, had more freedom to go out, and had less perception of care from school adults and neighborhood. Girls in the sex exploratory group were older and less likely to make decisions on their own. Given the result we found, we call for health researchers and educators to conduct sex education programs promoting more equal gender norms and provide services to help young adolescents get right information and strengthen their skills in communication, decision making and critical thinking.

Longitudinal Trajectories of Four Domains of Parenting in Relation to Adolescent Age and Puberty in Nine Countries

Children, mothers, and fathers in 12 ethnic and regional groups in nine countries (N = 1,338 families) were interviewed annually for 8 years (M_age child = 8-16 years) to model four domains of parenting as a function of child age, puberty, or both. Latent growth curve models revealed that for boys and girls, parents decrease their warmth, behavioral control, rules/limit-setting, and knowledge solicitation in conjunction with children's age and pubertal status as children develop from ages 8 to 16 across a range of diverse contexts, with steeper declines after age 11 or 12 in three of the four parenting domains. National, ethnic, and regional differences and similarities in the trajectories as a function of age and puberty are discussed.

Pornography Use Prevalence and Associated Factors in Arab Countries: A Multinational Cross-Sectional Study of 15,027 Individuals

BACKGROUND

There has been a tangible increase in pornography consumption during the past decade, with the absence of a large-scale study of Arab countries.

AIM

The present study aimed to assess the prevalence of pornography viewing and its associated risk factors in Arab countries.

METHODS

A large cross-sectional online survey was carried out recruiting participants without restrictions on the age, socioeconomic level, job, or educational level. Multivariable logistic regression analysis was performed to identify possible risk factors for viewing porn and results were expressed as odds ratios (ORs) and 95% confidence interval (95% CI).

OUTCOMES

Main outcomes were pornography viewing (first exposure and frequency), the perceptions of this act, use of spare time, physical activity (exercising), and frequency of psychiatrist visits.

RESULTS

The final number of participants included in the study was 15027 participants with a mean age ± standard deviation of 23.82 years ± 24.99. Most of the participants were men (84.56%), living with parents (81.71%), and 60.51% university graduates. There were statistically significant differences (P < .001) in the attitude and practice of men compared with women throughout all tested variables. Frequent pornography viewing was associated with male gender (OR [95% CI] = 7.08 [6.43 to 7.81]; P < .001) and age group ≤15 years (OR [95% CI] = 1.33 [1.01 to 1.75]; P = .044). By contrast, higher education was inversely associated with viewing rates reaching the lowest level in PhD awardees (OR [95% CI] = 0.36 [0.26 to 0.51]; P = .003). It was also noted that regular exercising (OR [95% CI] = 0.66 [0.58 to 0.74]; P < .001) was associated with a reduction in pornography viewing rates.

CLINICAL IMPLICATIONS

Young age, male gender, and lower educational level are all predictors for higher pornography viewing and should be considered when designing public health intervention in a related context.

STRENGTHS AND LIMITATIONS

This is the first large-scale multi-national survey to be conducted in Arab countries to investigate pornography viewing. The main limitations were the cross-sectional design (cannot indicate causality) and the self-report nature (liable to social desirability and recall bias).

CONCLUSION

Pornography viewing is common in Arab countries and associated with some personal and behavioral factors. Eljawad MA, Se'eda H, Ghozy S, et al. Pornography Use Prevalence and Associated Factors in Arab Countries: A Multinational Cross-Sectional Study of 15,027 Individuals. J Sex Med 2021;18:539-548.

Pubertal timing predicts adult psychosexuality: Evidence from typically developing adults and adults with isolated GnRH deficiency

Evidence suggests that psychosexuality in humans is modulated by both organizational effects of prenatal and peripubertal sex steroid hormones, and by activational effects of circulating hormones in adulthood. Experimental work in male rodents indicates that sensitivity to androgen-driven organization of sexual motivation decreases across the pubertal window, such that earlier puberty leads to greater sex-typicality. We test this hypothesis in typically developing men (n = 231) and women (n = 648), and in men (n = 72) and women (n = 32) with isolated GnRH deficiency (IGD), in whom the precise timing of peripubertal hormone exposure can be ascertained via the age at which hormone replacement therapy (HRT) was initiated. Psychosexuality was measured with the Sexual Desire Inventory-2 (SDI-2) and Sociosexual Orientation Inventory-Revised (SOI-R). In both sexes, earlier recalled absolute pubertal timing predicted higher psychosexuality in adulthood, although the magnitude of these associations varied with psychosexuality type and group (i.e., typically developing and IGD). Results were robust when controlling for circulating steroid hormones in typically developing participants. Age of initiation of HRT in men with IGD negatively predicted SOI-R. We discuss the clinical implications of our findings for conditions in which pubertal timing is medically altered.

Effects of Individual Mortality Experience on Out-of-Wedlock Fertility in Eighteenth- and Nineteenth-Century Krummhörn, Germany

Life history theory predicts that exposure to high mortality in early childhood leads to faster and riskier reproductive strategies. Individuals who grew up in a high mortality regime will not overly wait until they find a suitable partner and form a stable union because premature death would prevent them from reproducing. Cox proportional hazard models were used to determine whether women who experienced sibling death during early childhood (0–5 years) reproduced earlier and were at an increased risk of giving birth to an illegitimate child, with illegitimacy serving as a proxy for risky sexual behavior. Furthermore, we investigate whether giving birth out of wedlock is influenced by individual mortality experience or by more promiscuous sexual behavior that is clustered in certain families. Models are fitted on pedigree data from the eighteenth- and nineteenth-century Krummhörn population in Germany. The results show a relationship between sibling death in early childhood and the risk of reproducing out of wedlock, and reproductive timing. The risk of giving birth out of wedlock is linked to individual mortality experience rather than to family-level effects. In contrast, adjustments in connubial reproductive timing are influenced more by family-level effects than by individual mortality experience.

Onset Trajectories of Sexting and Other Sexual Behaviors Across High School: A Longitudinal Growth Mixture Modeling Approach

Sexting is receiving substantial scholarly attention and is now considered commonplace in adolescence. Little is known, however, about the normative contexts and the development of adolescent sexting behavior, including the initiation of sexting in relation to other sexual behaviors. In this study, we used growth mixture modeling to identify classes of onset trajectories for sexual behaviors across high school. Participants included 429 high school students (54% female) who completed annual assessments of sexual behavior over a three-year period. We identified four distinct classes: postponement (9%) with no behaviors other than hand-holding and kissing initiated by Grade 11, gradual onset (44%) with sexting and other sexual behaviors emerging incrementally across high school, continuous onset (32%) with sexting and other sexual behaviors within the first three years of high school, early onset (15%) with initiation of sexting and all other sexual behaviors prior to or by the end of Grade 9. Boys were more likely than girls to be members of the postponement versus gradual onset class, while Black students were more likely than White students to be members of the early versus gradual onset class. Sexting behavior appears to be common in adolescence and co-emerges with genital contact behavior across varying trajectories of sexual development. These findings provide the foundation for contextualizing sexting within normative sexual development. Further, this information can inform efforts to promote sexual health.

Spatial and demographic disparities in short stature among school children aged 7-18 years: a nation-wide survey in China, 2014

OBJECTIVES

To identify spatial disparities and demographic characteristics of short stature, we analysed the prevalence of short stature collected in a nationwide health survey.

SETTINGS

Data were obtained from the 2014 Chinese National Survey on Students Constitution and Health (a cross-sectional study of China). Participants came from 30 provinces, autonomous regions, and municipalities (except Tibet, Hong Kong, Macao, and Taiwan).

PARTICIPANTS

There were 213 795 Han school children between 7 and 18 years old enrolled in our study. All participants were sampled by stratified cluster.

PRIMARY AND SECONDARY OUTCOME MEASURES

Short stature; Chinese and WHO age-specific and gender-specific height growth references were used for short stature assessment.

RESULTS

The age-standardised and age-gender-standardised prevalence of short stature nationwide was 3.70% and 2.69% according to Chinese and WHO growth references, respectively. The short stature prevalence differed significantly among age groups, urban and rural areas, and regions with different socioeconomic development levels (all p<0.0001). The prevalence was 2.23% in urban versus 5.12% in rural areas (p<0.001). The prevalence was 2.60% in developed, 3.72% in intermediately developed, and 4.69% in underdeveloped regions (p<0.0001). These values were all according to China's growth reference, but similar patterns were observed on prevalence based on the WHO reference. The spatial distribution of prevalence of short stature presented a clustered pattern. Moran's I value was 0.474 (p<0.001) and 0.478 (p<0.001) according to the Chinese and WHO growth references, respectively. The southwest part of China showed a higher prevalence of short stature, whereas lower prevalence of short stature was observed mainly in the northeast part of China.

CONCLUSIONS

There is an appreciably high prevalence of short stature in rural, underdeveloped areas of China. There are high prevalence spatial clusters of short stature in southwestern China. This provides corroborating evidence for a tailored strategy on short stature prevention and reduction in special areas.

Appropriate scaling approach for evaluating peak VO2 development in Southern Chinese 8 to 16 years old

Objective

To investigate scaling approaches for evaluating the development of peak VO₂ and improving the identification of low cardiopulmonary fitness in Southern Chinese children and adolescents.

Methods

Nine hundred and twenty Chinese children and adolescents (8 to 16 years) underwent graded cardiopulmonary exercise test on a treadmill until volitional exhaustion. Peak VO₂ was corrected for the effects of body mass by ratio or allometric scaling. Z score equations for predicting peak VO₂ were developed. Correlations between scaled peak VO₂, z scores, body size and age were tested to examine the effectiveness of the approach.

Results

Eight hundred and fifty-two participants (48% male) were included in the analyses. Absolute peak VO₂ significantly increased with age in both sexes (both P<0.05), while ratio-scaled peak VO₂ increased only in males (P<0.05). Allometrically scaled peak VO₂ increased from 11 years in both sexes, plateauing by 12 years in girls and continuing to rise until 15 years in boys. Allometically scaled peak VO₂ was not correlated with body mass, but remained correlated with height and age in all but the older girls. Peak VO₂ z score was not correlated with body mass, height or age.

Conclusions

Absolute and allometric scaled peak VO₂ values are provided for Hong Kong Chinese children and adolescents by age and sex. Peak VO₂ z scores improve the evaluation of cardiopulmonary fitness, allowing comparisons across ages and sex and will likely provide a better metric for tracking change over time in children and adolescents, regardless of body size and age.

Dutch Adolescents' Everyday Expressions of Sexual Behavior Trajectories Over a 2-Year Period: A Mixed-Methods Study

Using an extended definition of sexuality, this mixed-methods study builds on existing research into adolescents' emergent sexual development by longitudinally examining adolescents' sexual behavior trajectories (i.e., from less to more intimate sexual behavior). Over a 2-year period, 45 adolescents (M age = 15.9 years) reported on their sexual behavior using questionnaires and on their everyday expressions of sexuality in the form of semi-structured diaries. Cluster analysis using the questionnaire data identified three sexual behavior trajectories: a non-sexually active trajectory (meaning no or minor sexual behavior) (n = 29), a gradually sexually active trajectory (meaning step-by-step sexual behavior development) (n = 12), and a fast sexually active trajectory (meaning rapid sexual behavior development) (n = 4). Qualitative analysis using diaries revealed the following themes: romantic versus sex-related topics, desires, uncertainties, and references to the social context. In general, all adolescents reported more about romantic aspects of sexuality (than about sexual acts) in the diaries, regardless of their sexual behavior trajectory. Sexually active adolescents (i.e., gradual and fast) were more concerned with sexuality in their diaries, especially more with the physical aspects of sexuality, than non-active adolescents. Gradual adolescents experienced more desires about physical sexual contact and reported fewer references to their social network than non-active and fast adolescents. The findings suggest that sexual education that discusses the internal experiences of sexuality, such as feelings and thoughts, particularly the romantic aspects, may help adolescents process their preferences for different sexual and romantic acts and may contribute to healthy sexual development.

Family, Peer, and Pubertal Determinants of Dating Involvement Among Adolescents

This study examines the influence of family, peer, and biological contributors to dating involvement among early adolescents (11-14 years of age; n = 244). Further, we assess how parental monitoring may be modified by pubertal maturation and older sibling risky behavior. Data on delinquent peer affiliation, pubertal maturation, parental monitoring, older sibling risky behavior, and dating involvement were gathered through observations and surveys from adolescents, mothers, older siblings, and teachers. Results indicate that lower levels of parental monitoring and higher levels of older sibling risky behavior were related to adolescents' dating involvement through delinquent peer affiliation. Pubertal maturation was directly related to dating involvement for early daters. Findings emphasize the value of examining social and biological factors, in concert, over time.

Silence Speaks Volumes: Parental Sexual Communication Among Asian American Emerging Adults

Although parents greatly influence children’s early understandings of sexuality, little is known about how sexual communication transpires in Asian American families. Accordingly, the authors examined the amount and type of parental sexual communication recalled by 165 Asian American college students. Parents were perceived as providing very little information about a range of sexual topics. Communication was most minimal from fathers, among sons, and in homes marked with language barriers. At the same time, however, most participants could recall receiving restrictive sexual messages, in particular, daughters and participants having less acculturated parents. Qualitative results shed light on the specific types of sexual messages that parents provided. Together, results suggest that Asian American parents use implicit and nonverbal ways to communicate their sexual values.

Physical Intimacy and Sexual Coercion Among Adolescent Intimate Partners in the Philippines

This study explores perceptions about intimate relationships including perspectives of pressure and sexual coercion as experienced by unmarried Filipino adolescent males and females aged 15 to 19 years. The study design included an initial qualitative phase containing focus group discussions with adults and adolescents and key informant interviews with professionals, a community survey of 600 female and male adolescents, and in-depth interviews with selected survey respondents. The results indicated that sexual coercion was regarded as common in adolescent intimate relationships. Viewed from a broader perspective, it canoccurat any stage of the intimate process using a combination of methods. Of the 600 adolescent survey respondents, 64% reported whether they have ever practiced or experienced any form of pressure and coercion in their intimate relationships. Of this number, 321 were targets of coercion, whereas 65 admitted that they had perpetrated the coercive act. Among the victims, 42.3% were males and 64.6% were females (p < .0001). The use of verbal pressure to pursue coercive sex was commonly reported. Recommendations were made to facilitate a healthy sexual development among male and female adolescents.

Physical and neurobehavioral determinants of reproductive onset and success

The ages of puberty, first sexual intercourse and first birth signify the onset of reproductive ability, behavior and success, respectively. In a genome-wide association study of 125,667 UK Biobank participants, we identify 38 loci associated (P < 5 × 10(-8)) with age at first sexual intercourse. These findings were taken forward in 241,910 men and women from Iceland and 20,187 women from the Women's Genome Health Study. Several of the identified loci also exhibit associations (P < 5 × 10(-8)) with other reproductive and behavioral traits, including age at first birth (variants in or near ESR1 and RBM6-SEMA3F), number of children (CADM2 and ESR1), irritable temperament (MSRA) and risk-taking propensity (CADM2). Mendelian randomization analyses infer causal influences of earlier puberty timing on earlier first sexual intercourse, earlier first birth and lower educational attainment. In turn, likely causal consequences of earlier first sexual intercourse include reproductive, educational, psychiatric and cardiometabolic outcomes.

Lifestyle and Addictive Behaviors Among Chinese Adolescents in Hong Kong, Macau, Taipei, Wuhan, and Zhuhai-a First Cross-subculture Assessment

PURPOSE

This study aimed at assessing the differences in prevalence rates of common health behavior among adolescents in the five Chinese cities and the influential factors at the contextual and individual levels.

METHOD

We compared the standardized rates of three lifestyle behaviors (sedentary, dietary, and physical activity) and three addictive behaviors (cigarette smoking, alcohol consumption, and participation in gambling) among a sample of 13,950 adolescents. The sample was randomly selected from five cities, including Hong Kong, Macau, Taipei, Zhuhai, and Wuhan. Population size, GDP per capita, and literacy at the city level as well as parental monitoring and school performance at the student's level were assessed. Multi-level mixed effect models were used to examine the interaction of individual level factors with study sites.

RESULTS

The six health behaviors differed significantly across sites with the highest rates of alcohol consumption in Hong Kong (39.5 %), of cigarette smoking in Macau (9.8 %), and of gambling in Taipei (37.1 %) and Hong Kong (35.9 %). The city-level measures were associated with only a few behavioral measures. Relative to Hong Kong, parental monitoring had stronger association with the three addictive behaviors in the other sites.

CONCLUSION

Findings suggest that although the study sites share similar Chinese culture, students in the five cities differed from each other with regard to levels of health behaviors. Relative to the broad socioeconomic development, differences in parental monitoring played a significant role in explaining the observed difference.

Oral vs. Vaginal Sex Experiences and Consequences Among First-Year College Students

To fully understand late adolescents' experiences of oral sex, we must consider both risk and normative developmental perspectives. Sexual experiences include a range of behaviors, but research on sexual behaviors and consequences focuses primarily on vaginal sex. Oral sex occurs at rates similar to vaginal sex, and carries some, though less, risk than vaginal sex. The current study examined the event-level prevalence and consequences of oral sex compared to vaginal sex with other-sex partners in first-year college students. Daily data were from recently sexually active first-year college students (N = 253 people, 834 days; M age, 18.4 years; SD = 0.4; 56% female; 31% Hispanic/Latino; 17% African American, 14% Asian American/Pacific Islander, 25% European American, 12% multiracial) who reported on sexual behaviors and consequences. Both positive (intimacy, physical satisfaction) and negative (worrying about health, guilt) consequences were less common for oral than vaginal sex. Gender differences suggested that female adolescents may find vaginal sex more rewarding than oral sex, whereas male adolescents may find them equally rewarding.

Changes in Body Weight From Young Adulthood to Middle Age and Its Association With Blood Pressure and Hypertension: A Cross-Sectional Study in Hong Kong Chinese Women

BACKGROUND

Few studies have examined the associations of weight changes from young adulthood to middle age with blood pressure (BP) and hypertension among Hong Kong Chinese women.

METHODS AND RESULTS

Weight at age 18 (W18), current weight (Wcurrent), height, BP, demographics, and lifestyle factors were obtained from 1253 female nurses (35-65 years) by a self-administered questionnaire through mail survey in Hong Kong. The conditional relative weight (CRW; a residual of Wcurrent regressed on W18) was used to express the relative weight change from age 18 to current age. The study results show that from young adulthood to middle age, 76.9%, 15.1%, and 8.0% of women had weight gain, weight loss, and stable weight, respectively. Women in the weight loss group had heavier W18 than those in the weight gain group (P<0.05). Higher weight gain was associated with higher BP (P for trend <0.01). Women who belonged to the heaviest 10% both at age 18 and at present had highest BP than women in other weight categories. By giving W18, a 1-kg increase in weight change predicted 0.63 and 0.42 mm Hg increases in systolic and diastolic BP, respectively (both P<0.001) and 12% greater odds of being hypertension (95% confidence interval, 1.08, 1.17). The CRW was positively associated with BP and hypertension; no interaction was found between CRW and Wcurrent on BP/hypertension.

CONCLUSIONS

A majority of Chinese women tended to become heavier throughout adult life. More weight gain led to the higher BP. Weight change is an independent predictor for later-life BP and hypertension.

Transitions in body and behavior: a meta-analytic study on the relationship between pubertal development and adolescent sexual behavior

The present meta-analysis studies the relations of pubertal timing and status with sexual behavior and sexual risk behavior among youth aged 10.5-22.4 years. We included biological sex, age, and ethnicity as potential moderators. Four databases were searched for studies (published between 1980 and 2012) on the relation between pubertal timing or status and sexual behavior. The outcomes were (1) sexual intercourse; (2) combined sexual behavior; and (3) risky sexual behavior. Earlier pubertal timing or more advanced pubertal status was related to earlier and more sexual behavior, and earlier pubertal timing was related to more risky sexual behavior. Further, the links between (1) pubertal status and combined sexual behavior and (2) pubertal timing and sexual intercourse status, combined sexual behavior, and risky sexual behavior were stronger for girls than boys. Most links between pubertal status, timing, and sexual behavior and sexual risk behavior were stronger for younger adolescents. Moderation by ethnicity did not yield consistent results. There was significant variation in results among studies that was not fully explained by differences in biological sex, age, and ethnicity. Future research is needed to identify moderators that explain the variation in effects and to design sexual health interventions for young adolescents.

Family and peer support matter for precoital and coital behaviors among adolescents in Lima

We analyzed the association between sub-scales developed with adolescents and the outcomes of precoital behaviors and vaginal sex in Lima, Peru. Adolescent participants in key informant sessions operationalized concepts identified during qualitative concept mapping into several sub-scales. Face and content validity testing and pilot application with respondent debriefing were used to refine the sub-scales. Three hundred 15-17 year olds were surveyed about the sub-scales, socio-demographics and sexual behaviors. Exploratory factor analysis confirmed six sub-scales, self-image, goals and decision-making, family education, parental rules/control, school support and peer support, which we regressed on the outcomes. Twice as many males as females reported more than three precoital behaviors and vaginal sex. Higher peer support reduced the likelihood of vaginal sex and precoital behaviors and higher family education reduced precoital behaviors. Results affirm the importance of including adolescents in the entire research process and of sex education with family- and peer-based strategies.

Frequent nocturnal awakening in children: prevalence, risk factors, and associations with subjective sleep perception and daytime sleepiness

BACKGROUND

Nocturnal awakening is the most frequent insomnia complaint in the general population. In contrast to a growing knowledge based on adults, little is known about its prevalence, correlated factors, and associations with subjective sleep perception and daytime sleepiness in children. This study was designed to assess the prevalence and the correlate factors of frequent nocturnal awakening (FNA) among Chinese school-aged children. Furthermore, the associations of FNA with subjective sleep perception and daytime sleepiness were examined.

METHODS

A random sample of 20,505 children aged 5.00 to 11.92 years old (boys: 49.5% vs. girls: 50.5%) participated in a cross-sectional survey, which was conducted in eight cities of China. Parent-administered questionnaires were used to collect information on children's sleep behaviors, sleep perception, and potential influential factors of FNA from six domains. Univariate and multivariate logistic regression models were performed.

RESULTS

The prevalence of FNA was 9.8% (10.0% for boys vs. 8.9% for girls) in our sampled children. The prominent FNA-related factors inclued biological health problems, such as overweight/obesity (OR = 1.70), chronic pain during night (OR = 2.47), and chronic respiratory condition (OR = 1.23), poor psychosocial condition, such as poor mental and emotional functioning (OR = 1.34), poor sleep hygiene, such as frequently doing exciting activities before bedtime (OR = 1.24) and bedtime resistance (OR = 1.42), and parents' history of insomnia (OR = 1.31). FNA was associated with subjective poor sleep quality (OR = 1.24), subjective insufficient sleep (OR = 1.21), and daytime sleepiness (OR = 1.35).

CONCLUSION

FNA was associated with poor sleep and daytime sleepiness. Compared to sleep environment and family susceptibility, chronic health problems, poor psychosocial condition, and poor sleep hygiene had greater impact on FNA, indicating childhood FNA could be partly prevented by health promotion, by psychological intervention, and by improving sleep hygiene routine.

Staying alone or getting attached: development of the motivations toward romantic relationships during adolescence

The authors present the initial validation of a romantic relationship motivation scale, enabling the level of self-determined involvement in romantic relationships during adolescence to be examined. The inclusion of Self-Determination Theory (E. L. Deci & R. M. Ryan, 2000) in the motivational constructs enhances the developmental perspective regarding adolescent romantic involvement. The scale was administered to 284 adolescents (163 girls and 121 boys, age 14-19 years) with a self-esteem scale and some questions about their romantic experiences to provide some elements of external validation. The results confirmed the 4-factor structure: intrinsic motivation, identified regulation, external regulation, and amotivation, which follow the self-determination continuum, previously highlighted in friendship motivation. As hypothesized, adolescents became more self-determined with age and girls were more self-determined than boys. Other findings show specific links between motivation for romantic relationships, self-esteem and romantic experiences. It highlights the importance of considering adolescents' motivations when exploring their romantic relationships.

Age at menarche and age at first sexual intercourse: a prospective cohort study

OBJECTIVE

Younger age at menarche (AAM) may put girls at risk for earlier first sexual intercourse (FSI). Young age at FSI has far-reaching negative outcomes. We describe the longitudinal relationship between AAM and FSI in a large prospective birth cohort.

METHODS

AAM was collected from 554 girls from the Western Australia (Raine) Pregnancy Cohort Study, prospectively from age 10 or retrospectively at age 14. Age at FSI was collected at ages 17 and 20. Cox regression models describe likelihood of FSI by age and years since menarche for younger (<12 years) and older (≥14 years) AAM relative to average AAM (12-13 years).

RESULTS

Girls with younger AAM and average AAM were equally likely to have FSI by age 16 (adjusted hazard ratio [aHR]: 0.90 [95% confidence interval (CI): 0.60-1.35]). FSI by age 16 was less likely among girls with older AAM than those with average AAM (aHR: 0.35 [95% CI: 0.17-0.72]). Girls with younger AAM had a longer median interval between menarche and FSI than girls with average AAM (5.0 years [interquartile range: 4.4-8.5 years] vs 3.7 years [interquartile range: 2.4-5.3 years]). Those with younger AAM were less likely to report FSI within 4 years of menarche than those with average AAM (0-2 years aHR: 0.04 [95% CI: 0.01-0.31]; 2-4 years aHR: 0.36 [95% CI: 0.23-0.55]). By age 20, 429 girls (77.4%) reported FSI.

CONCLUSIONS

Younger AAM was not a risk factor for younger age at FSI in this cohort.

Acceptability and uptake of female adolescent HPV vaccination in Hong Kong: a survey of mothers and adolescents

BACKGROUND

Organized population-based HPV vaccination programs can be effective in reducing the burden of cervical cancer, especially in the absence of a comprehensive cervical screening program (e.g. Hong Kong). Assessment of vaccine acceptability is important when evaluating the feasibility and cost-effectiveness of such vaccination programs.

METHODS

To provide a more representative and updated assessment on the acceptability of female adolescent HPV vaccination in Hong Kong, we conducted surveys in 2008 among 1022 mothers with daughters aged ≤ 18 years through random digit-dialing telephone interviewing and 2167 schoolgirls aged 11-18 years using two-stage stratified cluster sampling. We conducted the maternal survey again in 2012 with an independent group of 1005 mothers.

RESULTS

In 2008, 2.4% (95% confidence interval [CI]=1.8-3.2%) of the recruited schoolgirls reported having received HPV vaccination. In 2012, the mothers reported that 9.1% (7.0-11.6%) of their daughters who were in the same age range (11-18 years) as the schoolgirls had been vaccinated (p<0.01). Regarding acceptability, 27.5% (24.8-30.4%) and 37.6% (34.5-40.8%) of the mothers were willing to have their daughters vaccinated at market price in 2008 and 2012 (p<0.01), respectively. 27.1% (25.2-29.1%) of the schoolgirls were willing to receive HPV vaccination at market price in 2008. The willingness to pay for full-course vaccination among mothers had a median of US$128/HK$1000 (50% central range=US$64-192/HK$500-1500), i.e. substantially lower than the current market price.

CONCLUSIONS

The gap between acceptability and actual uptake of HPV vaccination among adolescent girls suggested that coverage is likely to be low without an organized HPV vaccination program, although the difference might be partially attributed to the possibility that at the time of the interview female adolescents who were willing to be vaccinated had not yet taken action. Policymakers should devise tailored, targeted and efficient vaccination strategies to achieve universal coverage for an effectively organized HPV vaccination program.

Genetic influences on adolescent sexual behavior: Why genes matter for environmentally oriented researchers

There are dramatic individual differences among adolescents in how and when they become sexually active adults, and early sexual activity is frequently cited as a cause of concern for scientists, policymakers, and the general public. Understanding the causes and developmental impact of adolescent sexual activity can be furthered by considering genes as a source of individual differences. Quantitative behavioral genetics (i.e., twin and family studies) and candidate gene association studies now provide clear evidence for the genetic underpinnings of individual differences in adolescent sexual behavior and related phenotypes. Genetic influences on sexual behavior may operate through a variety of direct and indirect mechanisms, including pubertal development, testosterone levels, and dopaminergic systems. Genetic differences may be systematically associated with exposure to environments that are commonly treated as causes of sexual behavior (gene-environment correlation). Possible gene-environment correlations pose a serious challenge for interpreting the results of much behavioral research. Multivariate, genetically informed research on adolescent sexual behavior compares twins and family members as a form of quasi experiment: How do twins who differ in their sexual experiences differ in their later development? The small but growing body of genetically informed research has already challenged dominant assumptions regarding the etiology and sequelae of adolescent sexual behavior, with some studies indicating possible positive effects of teenage sexuality. Studies of Gene × Environment interaction may further elucidate the mechanisms by which genes and environments combine to shape the development of sexual behavior and its psychosocial consequences. Overall, the existence of heritable variation in adolescent sexual behavior has profound implications for environmentally oriented theory and research.

Female pubertal timing and problem behaviour

We tested the peer-socialization/contextual-amplification explanation for the link between early female puberty and problem behaviour. We propose that in cultures with high tolerance for adolescent heterosexual involvement, early puberty should be linked with problem behaviour—not in other cultures. We compared girls in two cultures (Slovakia and Sweden) that differ in acceptance of adolescent girls’ heterosexual involvement. Findings supported the hypothesis by showing that in Sweden, a culture that facilitates adolescent heterosexual involvement, early-maturing girls reported more problem behaviours than in Slovakia. The mediation link (heterosexual involvement as the mechanism linking early puberty with problem behaviour) was moderated by culture. The findings expand our understanding of the role of macro-cultural contexts in the developmental significance of female puberty.

Puberty and adolescent sexuality

This article is part of a Special Issue "Puberty and Adolescence". Sexuality emerges as a major developmental element of puberty and the adolescent years that follow. However, connecting the sexuality that emerges with puberty and elements of adult sexuality is difficult because much adolescent sexuality research addresses the transition to partnered sexual behaviors (primarily coitus) and consequences such as unplanned pregnancy and sexually transmitted infections. This review proposes a framework of an expanded understanding of puberty and adolescent sexuality from the perspective of four hallmarks of adult sexuality: sexual desire; sexual arousal; sexual behaviors; and, sexual function. This approach thus addresses important gaps in understanding of the ontogeny of sex and the continuum of sexuality development from adolescence through the adult lifespan.

Validity of self-estimated adiposity assessment against general and central adiposity in Hong Kong adolescents

BACKGROUND AND AIM

The relationships between self-estimated adiposity using Stunkard's body silhouette scale with general and central adiposity in adolescents are unclear. This study examines the criterion validity of Stunkard's body silhouette scale as a self-estimated rating of adiposity against anthropometric measures of adiposity and percentage body fat in Hong Kong adolescents.

SUBJECTS AND METHODS

The body composition of 903 adolescents (55.7% boys) was assessed by measured waist circumference (WC), waist-to-stature ratio (WSR), body mass index (BMI) and percentage body fat (%BF). Self-estimated adiposity was subjectively assessed using Stunkard's body silhouette scale. The association between self-estimated adiposity and body composition was examined by Spearman correlation coefficients and hierarchical multiple regression analyses.

RESULTS

Self-estimated adiposity correlated significantly and positively with BMI (boys: r = 0.65; girls: r = 0.59), WC (boys: r = 0.62; girls: r = 0.51), WSR (boys: r = 0.55; girls: r = 0.42) and %BF (boys: r = 0.47; girls: r = 0.55).

CONCLUSION

Self-estimated adiposity using the Stunkard's body silhouette scale was positively associated with actual measures of adiposity; however, the association was modest at best. It is unlikely that the Stunkard's body silhouette scale provides a suitably accurate substitute for actual body composition measures in Chinese adolescents.

Age-concordant and age-discordant sexual behavior among gay and bisexual male adolescents

There is evidence that risks for HIV and sexually transmitted infections among adolescent females are higher for those with older male sexual partners. Yet, little empirical research has been conducted with male adolescents who engage in sexual activity with older men. In this article, we summarize in a number of ways the range of sexual activity reported by an ethnically diverse sample of 200 gay and bisexual male youth (15-22 years old) in Chicago and Miami. A general pattern of progression from oral sex with men to both receptive and insertive anal sex with men appeared to characterize the sample during their adolescence. Further, there appeared to be a high degree of "versatile" positioning among the sexually active gay and bisexual young men, in both age-discrepant and age-concordant dyads. Risk analysis revealed having primarily age-concordant partners to be a significant predictor of sexual risk behavior. HIV risk among young gay and bisexual men engaging in sexual activity with older men may occur not only within a distinct biological context from their heterosexual counterparts, but also in a social context that may not as rigidly bound to traditional assumptions about age, gender, and power. The significant associations among participants with partners who were the same age and the risk behavior measures in this analysis have implications for HIV prevention efforts.

The role of early maturation, perceived popularity, and rumors in the emergence of internalizing symptoms among adolescent girls

Despite the widely reported link between early pubertal timing and internalizing symptoms among girls, less is known about the peer reputation of earlier maturing girls. The current study assesses whether early maturation is associated with perceived popularity and/or rumors, and whether these reputational factors help account for earlier maturing girls' vulnerability to emotional distress. Drawing on three waves of data collected from an ethnically diverse sample of middle school girls (n = 912), hierarchical multiple regression analyses revealed that more advanced development at the start of middle school predicted peer- and teacher-reported popularity as well as increased risk of being targeted for rumors. Mediation analyses suggested that popularity among boys can put earlier developing girls at risk for rumors. Finally, rumors acted as a partial mechanism through which early maturation was associated with subsequent internalizing symptoms. Knowledge of the peer mechanisms putting earlier developing girls at risk for psychosocial maladjustment can inform intervention and prevention efforts aimed at improving adolescent well-being.

Why don't smart teens have sex? A behavioral genetic approach

Academic achievement and cognitive ability have been shown to predict later age at first sexual intercourse. Using a sample of 536 same-sex twin pairs who were followed longitudinally from adolescence to early adulthood, this study tested whether relations between intelligence, academic achievement, and age at first sex were due to unmeasured genetic and environmental differences between families. Twins who differed in their intelligence or their academic achievement did not differ in their age at first sex. Rather, the association between intelligence and age at first sex could be attributed entirely to unmeasured environmental differences between families, whereas the association between academic achievement and age at first sex could be attributed entirely to genetic factors.

Reported early family environment covaries with menarcheal age as a function of polymorphic variation in estrogen receptor-α

Age at menarche, a sentinel index of pubertal maturation, was examined in relation to early family relationships (conflict, cohesion) and polymorphic variation in the gene encoding estrogen receptor-α (ESR1) in a midlife sample of 455 European American women. Consistent with prior literature, women who reported being raised in families characterized by close interpersonal relationships and little conflict tended to reach menarche at a later age than participants reared in families lacking cohesion and prone to discord. Moreover, this association was moderated by ESR1 variation, such that quality of the family environment covaried positively with menarcheal age among participants homozygous for minor alleles of the two ESR1 polymorphisms studied here (rs9304799, rs2234693), but not among women of other ESR1 genotypes. In addition, (a) family relationship variables were unrelated to ESR1 variation, and (b) genotype-dependent effects of childhood environment on age at menarche could not be accounted for by personality traits elsewhere shown to explain heritable variation in reported family conflict and cohesion. These findings are consistent with theories of differential susceptibility to environmental influence, as well as the more specific hypothesis (by Belsky) that girls differ genetically in their sensitivity to rearing effects on pubertal maturation.

Adolescent sexual activity and the development of delinquent behavior: the role of relationship context

Despite the well-established association between adolescent sexual activity and delinquent behavior, little research has examined the potential importance of relationship contexts in moderating this association. The current study used longitudinal, behavioral genetic data on 519 same-sex twin pairs (48.6% female) divided into two age cohorts (13-15 and 16-18 years olds) drawn from the National Longitudinal Study of Adolescent Health. Analyses tested whether adolescent sexual activity that occurred in romantic versus non-romantic relationships was associated with delinquency from adolescence to early adulthood, after controlling for genetic influences. Results indicated that, for both younger and older adolescents, common underlying genes influence both sexual behavior and delinquency. After controlling for these genetic influences, there was no within-twin pair association between sexual activity and delinquency in younger adolescents. In older adolescents, sexual activity that occurred in romantic relationships predicted lower levels of delinquency, both cross-sectionally and longitudinally, whereas sexual activity in non-romantic relationships predicted higher levels of delinquency. These results are consistent with emerging research that suggests that the psychological correlates of adolescent sexual activity may be moderated by the social context in which this activity occurs.

Social anxiety level in Turkish adolescents

Social phobia is a mental disorder characterized by extreme and consistent fear of meeting new people, scrutiny in a variety of performance and/or interactional situations. The aim of this study was to investigate the level of self-reported social anxiety in a community sample of Turkish adolescents and the relationship between social anxiety and some sociodemographic parameters. This study was a school-based cross-sectional study. Students in grades 6-8 (aged 10-16) from 12 schools in Kocaeli/Turkey were screened by the Social Anxiety Scale for Adolescents (SAS-A). The correlations of sociodemographic parameters with the SAS-A scores were examined. Data from a sample of 1,713 students (865 boys 50.4% and 848 girls 49.5%) were analyzed. A significant gender difference in the SAS-A points was found. Boys reported higher SAS-A total and subscale scores (except social avoidance and distress-general subscale score) than did girls. A significant negative correlation was found between socioeconomic status and social anxiety level. SAS-A scores were higher in those with a low socioeconomic level, and who were going to rural schools. The result of this study showed that social phobic symptoms among Turkish adolescents were more severe in boys. Some factors such as low socioeconomic level, and going to a rural school had impact on the SAS-A scores. As the impairment in the school-domain was reported to be quite high, professionals and teachers need to recognize social anxiety in adolescents, so that help can be offered to overcome the difficulties social phobia causes.

Timing of sexual maturation and women's evaluation of men

Many antecedents and consequences of an accelerated sexual maturation are associated with negative experiences with the opposite sex. Here we show a connection between menarcheal age, a salient sign of female sexual maturation, and the implicit attitude toward men in later adulthood. In Study 1, earlier age at first menstruation was associated with automatic negative evaluations of male faces but not female ones. Study 2 revealed a relationship between early age of menarche and an implicit association between the concepts male and danger. In Study 3, the earlier the menarche, the larger was the estimated egocentric distance of virtual male voices and the shorter the estimated distance of female voices. These results, obtained about a decade after onset of menstruation, suggest that apparently subtle differences in the onset of sexual maturation may have long-lasting implications for intersexual relationships.

Measurement of pubertal status with a Chinese self-report Pubertal Development Scale

This cross sectional study of 290 Chinese children aged 8-18 years, evaluated a Chinese version of the self-reported Pubertal Development Scale (PDS) against both raters' and self-reported Tanner assessment of pubertal status. Children completed both the self-reported PDS and self-reported Tanner pubertal questionnaire prior to physical examination through visual depiction by a same gender rater. Puberty Category Scores (PCS) which were derived from the PDS, was used to categorize children into one of five pubertal development stages. Tanner derived composite stage (TDCS) which was derived from the Tanner pubertal questionnaires, was used to compare with PCS to obtain the inter-rater agreement. Moderately high agreements were found between raters' TDCS and PCS in girls [weighted kappa (WK) 0.57 (0.44, 0.71); Kendalltau-b 0.60 (0.51, 0.69)] and in boys [WK 0.58 (0.47, 0.69), Kendalltau-b 0.50 (0.38, 0.62)]. The correlation between self-reported PDS and rater's assessment was substantial in girls [Kendalltau-b 0.61 (0.54, 0.69)] and moderate in boys [Kendalltau-b 0.49 (0.38, 0.61)]. The Hong Kong Chinese children and adolescents were able to reliably estimate their own sexual maturation status (SMS) using a Chinese version PDS. This instrument may be useful in epidemiological studies when cost, privacy and other concerns preclude the use of other SMS assessment tools.

A community-based study of insomnia in Hong Kong Chinese children: Prevalence, risk factors and familial aggregation

OBJECTIVES

There has been limited data on familial aggregation of insomnia. We aimed to explore the prevalence, risk factors and familial aggregation of childhood insomnia with a large community-based sample.

METHODS

A community-based epidemiologic study of sleep disorders was conducted among primary school children. Those children with at least one reported biological parent were recruited. A total of 5695 children (mean age 9.2; SD 1.8), 4939 of their reported biological mothers (mean age 38.9; SD 4.6) and 4289 of their reported biological fathers (mean age 43.3; SD 5.5) were studied.

RESULTS

The rates of insomnia 3 times/week in the past 12 months were 4.0%, 12.8% and 9.7% for children, mothers and fathers, respectively. A robust familial aggregation of insomnia was found even after adjustment of the shared environmental and socio-demographic factors. There was a significant dose-response relationship among the children across their parental status from neither, fathers, mothers to both parents with insomnia [3.0%, 7.1%, 9.5% and 11.9%; with ORs (95% CIs)=2.48 (1.82-4.37) for fathers, 3.42 (2.55-4.59) for mothers and 4.42 (2.42-8.10) for both parents, respectively]. In addition, the frequency of insomniac symptoms of the parents also had a dose-response effect on the rate of insomnia of their children.

CONCLUSIONS

Insomnia is a common problem in both children and their parents. A significant familial aggregation of childhood onset insomnia was seen in this study even after adjustment of the co-risk factors. There was a dose-response effect of parental insomnia on the rate of insomnia of their children with a slight predilection of maternal influences.

Sexual trajectories during adolescence: relation to demographic characteristics and sexual risk

The "sexual trajectory" is an age-graded set of various new sexual experiences, defined by three key dimensions: sequence, duration, and timing. A comprehensive description of sexual trajectories creates the possibility to investigate potential risks of certain trajectory types. The present study attempted to answer three questions: (1) Is it possible to identify a typology in (the early stages of) sexual trajectories? (2) Is sexual trajectory type related to demographic characteristics, such as sex, ethnic background, and educational level? (3) What are the associations between sexual trajectory type and recent sexual risk behavior? A representative Dutch sample of 1,263 males and 1,353 females (M = 20.46 years; range, 12-25) who had engaged in sexual intercourse completed a questionnaire about sexual (health) behavior. About three quarters of participants followed a progressive sexual trajectory from less intimate (e.g., kissing) to more intimate behavior (e.g., sexual intercourse). Immigrant groups and less educated youth were more likely to follow a nonlinear trajectory. A progressive trajectory was associated with a higher likelihood of consistent contraceptive use with the most recent partner and, for girls, with a lower likelihood of having unprotected anal intercourse with the last partner. It was hypothesized that the nonlinear trajectory could be ascribed to a lack of opportunities or skills to plan and steer early sexual experiences and that these limitations were fairly stable over time. Sexual education should aim at providing adolescents with sufficient (self) knowledge and skills to construct their sexual trajectories according to their own wishes or needs.

Reliability of pubertal self-assessment in Hong Kong Chinese children

AIM

To validate a Tanner stages self-assessment questionnaire using gender-specific line drawings and brief explanatory text in Chinese.

DESIGN

A cross sectional study design.

SETTING

One primary and two secondary schools.

PARTICIPANTS

172 boys and 182 girls aged between 8 and 18 years.

MAIN OUTCOME MEASURES

Students' self-assessments of pubertal maturation were compared with assessments made by a same gender rater using visual depiction physical examination. Raters' physical examinations were performed after the children had answered the self-assessment questionnaire individually and in private. Raters were blinded to the self-assessment results. Accuracy rates and weighted kappa statistic were used to evaluate the degree of agreement between children and raters.

RESULTS

Substantial to almost perfect agreement was found between self- and rater's assessments of breast development and pubic hair growth in girls [weighted kappa 0.72 (P < 0.0001, 95% CI 0.66, 0.79) and 0.83 (P < 0.0001, 95% CI 0.78, 0.87) respectively]. Moderate to substantial agreement was found between self- and rater's assessments of male genital development and pubic hair growth [weighted kappa 0.58 (P < 0.0001, 95% CI 0.48, 0.68) and 0.80 (P < 0.0001, 95% CI 0.74, 0.86) respectively]. Most agreements between self- and rater's assessments differed by only one Tanner stage. Agreement was higher for girls than boys. Girls tended to overestimate their breast stages and boys tended to underestimate their genitalia development.

CONCLUSION

This study confirms that a Tanner pubertal self-assessment questionnaire with line drawings and explanatory Chinese text can reliably estimate sexual maturation status in Hong Kong Chinese children.

Reliability and validity of the Chinese version of the Social Anxiety Scale for Adolescents

This study evaluated the psychometric properties of the Chinese version of the Social Anxiety Scale for Adolescents (SAS-A) in a sample of 296 adolescents (49% boys) in Grades 7, 8, 9, 10, and 12 with a mean age of 15.52 years. Confirmatory factor analysis replicated the three-factor structure of the SAS-A in the Chinese sample: Fear of Negative Evaluation (FNE), Social Avoidance and Distress in New Situations (SAD-New), and Social Avoidance and Distress-General (SAD-General). Internal consistency and test-retest reliability were appropriate. The results also revealed a clear and predictable pattern of relationships between the SAS-A and the Questionnaire about Interpersonal Difficulties for Adolescents and the International Personality Item Pool. Chinese boys reported greater SAD-General than Chinese girls, and this difference increased with grade. The SAS-A scores were compared to previously collected data from the USA and Spain, revealing that Chinese adolescents scored significantly higher in social anxiety than American and Spanish adolescents.

Biological, familial, and peer influences on dating in early adolescence

The current study examined the joint contributions of pubertal maturation, parental monitoring, involvement in older peer groups, peer dating, and peer delinquency on dating in a sample of early adolescent boys and girls. The sample consisted of 784 adolescents (394 boys, 390 girls) enrolled in grades 5, 6, and 7 who were followed for one year. In addition to measures of pubertal maturation and parental monitoring, adolescents and their peer group members completed indices of dating and delinquency. Average dating and delinquency scores for each participant's peer group network were computed. Results indicated that it was the combination of pubertal maturation, peer delinquency, and peer dating that explained increases in early dating. For boys only, parental monitoring was a significant predictor. The more knowledgeable parents were about their boys' activities, the lower the number of dating activities reported. These results highlight the importance of considering the joint effects of these biological and social predictors in understanding early dating. When rapid changes occur in all three domains, early dating is most likely to ensue. The findings of this study have practical importance. Parents and professionals who work closely with youth should attend to the special vulnerability of early maturing adolescents in the face of peer pressure and to the important role of parental monitoring in regulating dating activities.

Detrimental Psychological Outcomes Associated with Early Pubertal Timing in Adolescent Girls

Though often discussed as though it were a discrete event, puberty comprises one segment of a larger developmental continuum and is notable for rapid transformation across a multitude of domains. Research suggests that an earlier rate of pubertal maturation in girls correlates with a number of detrimental outcomes compared with on-time or later maturation. The present review synthesizes the research on negative psychological sequelae of early pubertal timing in adolescent girls. Emphasis is on three theoretical perspectives by which precocious development is believed to affect the emergence of adverse outcomes: biological, psychosocial, and selection effects.