Fitness is always relative to the fitness of others in the group or breeding population. Even in very low-fertility societies, individual fitness as measured by the share of genes in subsequent generations may still be maximized. Further, sexual selection theory from evolutionary biology suggests that the relationship between status and fertility will differ for males and females. For this reason it is important to examine the relationship between status and fertility separately for males and females–something few demographic studies of fertility do. When male fertility is measured separately, high-status men (as measured by their wealth and personal income) have higher fertility than low-status men, even in very low-fertility societies, so individual males appear to be maximizing their fitness within the constraints posed by a modern society. Thus male fertility cannot be considered maladaptive. When female fertility is measured separately, in both very high- and very low-fertility societies, there is not much variance across women of different statuses in completed fertility. Only in societies currently changing rapidly (with falling fertility rates) is somewhat high variance across women of different statuses in completed fertility found. What is seen across all phases of the demographic transition appears to be a continuation of two somewhat different evolved human reproductive strategies–one male, one female–in changing social and material contexts. Whether contemporary female fertility is maladaptive remains an open question.

There is a high and increasing proportion of single-parent families in Jamaica. This has raised concerns about the potential impact of single-parent families on the social, cognitive and behavioural development of children, including their sexual relationships. The aim of this study was to investigate the association between being raised in a single-parent family and age of sexual debut among young people in Jamaica. The study was cross-sectional in design, and based on a multi-stage sampling procedure. The study was conducted in July/September 2016. The study sample comprised 233 respondents (110 males and 123 females) aged from 18 to 35 years (mean 26.37 years; SD 5.46). Respondents completed a self-administered questionnaire with questions on socio-demographic characteristics, family structure, sexual debut and current sexual behaviour. Ninety-seven (41.7%) respondents grew up in single-parent families. A total of 201 (86.3%) had had sex (102 males and 99 females). Their mean age of sexual debut was 15.51 years (SD 3.41). Sixty-five (32.3%) had early sexual debut (<16 years). Respondents from single-parent families were more likely to have had early sexual debut (56.9%; n=37) compared with those from two-parent families (43.1%, n=28; p=0.004). Only 44.6% (n=29) of those who experienced early sexual debut used a condom during their first sexual encounter compared with 73% (n=100) of those who had a later sexual debut (≥16 years; p=<0.001). A single-father family structure was a significant predictor of early sexual debut (AOR 5.5; 95%CI: 1.1–25.8). The study found a significant association between single-parent family structure and age of sexual debut.

The aim of this study was to assess whether women’s empowerment ensures reduced intimate partner violence (IPV). The differential relationship between women’s empowerment and IPV among married women in Bangladesh was investigated using 2007 Demographic and Health Survey data. Logistic regression models were used to assess whether women’s empowerment had any influence on their likelihood of experiencing IPV while controlling for other covariates. The analyses revealed that older cohorts of women, who were more empowered, were more vulnerable to physical violence than less-empowered, younger women. The likelihood of being affected by physical violence among less-empowered, childless women was greater than that of more-empowered women with only male children. Less-empowered, uneducated women were more likely to experience physical violence than more-empowered, primary-educated women. Less-empowered women who had been married for less than 5 years were more likely to suffer from physical violence than more-empowered women who had been married for more than 19 years. The likelihood of experiencing sexual violence was not found to have any significant association with women’s empowerment. The findings suggest that although women’s empowerment in Bangladesh is gradually improving, some sub-groups of empowered women are still susceptible to IPV.

This study contributes to the dialogue on the prevention of mother-to-child HIV transmission (PMTCT) through the use of HIV and antenatal care (ANC) integrated services. The determinants of antenatal HIV testing in Zimbabwe were explored. Multilevel logistic regression models were applied to data for 8471 women from 406 clusters who gave birth in the 5 years preceding Zimbabwe Demographic and Health Surveys conducted in 2005/6 and 2010/11. The uptake of antenatal HIV testing was found to be determined by a wide range of individual-level factors relating to women’s economic and demographic status, as well as HIV-related factors, including HIV awareness and stigma within the community. Important individual-level enabling and perceived need factors included high socioeconomic status, not having observed HIV-related stigma and knowledge of HIV status (based on a previous HIV test), such that these groups of individuals had a significantly higher likelihood of being tested for HIV during pregnancy than their counterparts of lower socioeconomic status, and who had observed HIV-related stigma or did not know their HIV status. The results further revealed that community HIV awareness is important for improving antenatal HIV testing, while stigma is associated with reduced testing uptake. Most contextual community-level factors were not found to have much effect on the uptake of antenatal HIV testing. Therefore, policies should focus on individual-level predisposing and enabling factors to improve the uptake of antenatal HIV testing in Zimbabwe.

Global estimates suggest that over a billion people live with a disability that is significant enough to affect their daily lives. According to the 2011 Indian Census, India alone has about 26.8 million people with disabilities. Research suggests that persons with disabilities (PwDs) in India are among the most neglected, stigmatized, poor and least educated of the world’s population, and women with disabilities in India are the most marginalized, both socially and economically. They bear the triple burden of being discriminated against through being ‘women’ (socially marginal beings), ‘disabled’ (incapacitated, inefficient and undesirable) and ‘women with disabilities’ (the weakest of the weak), often becoming socially invisible. Although there has been a general recognition over the years that the educational and employment opportunities of PwDs in India need to be improved, their sexual needs and aspirations, sexuality concerns and sexual and reproductive health and rights have been largely ignored. The objective of this paper is to highlight the paucity of research on the sexual and reproductive health concerns of PwDs, particularly women, in the Indian context using existing literature on India, and to identify the possible reasons of this neglect. The study describes the obstacles faced by PwDs, particularly women, to acquiring good sexual and reproductive information and services, based on the results of empirical studies. Given the lack of research on this in India, the evidence largely comes from studies conducted elsewhere in the world. Lack of information and education about sexual health concerns, physical and/or infrastructural inaccessibility, judgemental provider attitudes, limited provider knowledge about disability issues and individual factors, including inhibitions about seeking health care and financial barriers, are identified as factors inhibiting the sexual and reproductive rights of people with disabilities in India.

Despite the ongoing problems of undernutrition and infectious disease, obesity and overweight have become a major problem in developing countries, including Bangladesh. This cross-sectional study was undertaken to determine the prevalence of obesity, overweight and underweight among school children aged 6–12 years in Bangladesh. The study was conducted from June 2012 to May 2013 and the study sample comprised 1768 children (980 boys; 788 girls) from eight purposively selected schools in different areas of Dhaka city. Students were interviewed about their diet and physical activity, and anthropometric measurements were made, including height, weight, mid-upper-arm circumference (MUAC), waist circumference, hip circumference and body mass index (BMI). Undernutrition, overweight and obesity were defined using internationally accepted BMI cut-off points. Mean height, weight, BMI, MUAC, waist circumference and hip circumference values were found to be higher in boys than in girls, except at age 12 when these were found to be significantly higher in girls than in boys (p<0.05). The mean prevalence of overweight was 10.0% (boys 10.2%; girls 9.8%), and that of obesity 5.0% (boys 4.3%; girls 5.8%). The prevalence of underweight was 16.3% in boys and 12.7% in girls. The prevalence of underweight was significantly higher in poor than in rich children (22.1% vs 11.2%) and that of obesity was higher in rich than in poor children (9.9% vs 1.3%; p<0.001). A family history of obesity and hypertension emerged as a significant predictor of developing overweight and obesity (p<0.001). The data suggest that underweight and obesity co-exist in urban areas of Bangladesh, posing a challenge for the nutritional health of Bangladeshi children.

The question of youth sexual behaviour has been widely debated, with researchers such as Berhan and Berhan (2015) arguing that young adults aged 15–24 are more likely to engage in risky behaviours. However, research has not adequately addressed the issue of positive sexual behaviours, in particular among young people in sub-Saharan Africa. Adapting the compensatory model of risk and resiliency theory, this study examined the determinants of positive sexual behaviours among youth in sub-Saharan Africa. Using recent data from Demographic and Health Surveys of sixteen countries representative of each African region (East, West, Southern and Central), it was hypothesized that positive sexual behaviours of youth (condom use at last sex and single sexual partnership) would be most strengthened by protective factors at the individual and family levels, and that these behaviours would differ by region due to regional variation in socio-cultural practices. Delayed age at sexual debut (first sex after the age of 15) was found to be the strongest protective factor for positive sexual behaviours among males and females in sub-Saharan Africa. Certain socioeconomic variables were found to be positively associated with positive sexual behaviours and the associations differed by gender.

Two administrations of the Coloured Progressive Matrices in Egypt were compared. The first was administered to a large, representative national sample between 2011 and 2013. The second was administered to primary school pupils in villages in Menoufia in northern Egypt in 2017. Adjusting for the Flynn Effect, the IQ of the rural northern Egyptians was shown to be statistically significantly higher than the national average. It is demonstrated that this is consistent with regional socioeconomic differences in Egypt, which strongly imply that northern Egypt has a higher average IQ than southern Egypt.

The aim of this study was to assess the knowledge of East Malaysian adolescents on sexual and reproductive health issues. Data were collected in March–July 2015 from 2858 adolescents aged 13–18 years from selected East Malaysian secondary schools using a self-administered questionnaire. Twelve items relating to sexual and reproductive health were used to measure respondents’ knowledge based on their responses ‘True’, ‘False’ or ‘Don’t know’, with the proportion of correct answers being the variable of interest. Cronbach’s alpha for the twelve items was 0.761 and the mean knowledge score was 6.8. While the majority of the respondents knew that a woman can get pregnant if she has sex with a man and that HIV and AIDS can be transmitted through sexual intercourse, knowledge about Malaysia’s abortion laws, that a woman can get pregnant if she has sex only once and that people with sexually transmitted infections may look healthy was poor. Older respondents and those from urban schools reported significantly higher knowledge than younger respondents and those from rural schools, respectively. More emphasis should be given in schools to the specific topics for which low levels of sexual and reproductive health knowledge were found, with greater attention being given to younger adolescents and those in rural areas.

The objective of this paper was to study nutritional status and growth, as measured by height and weight, over the life course and their connection with chronic diseases in Guatemala, a country with high levels of child undernutrition and adult overnutrition, using data from the Institute of Nutrition of Central America and Panama (INCAP) Nutrition Trial Cohort study. The study sample comprised a birth cohort of 1570 individuals who had data in the original 1969–1977 survey as well as the 2002–2004 follow-up, allowing for an analysis of the nutritional transition from childhood to adulthood. The associations between childhood and adulthood anthropometrics were analysed, and the links of these with chronic disease indicators were assessed using multiple regression analysis and structural equation modelling. Moving upwards in nutritional status from childhood to adulthood was observed frequently in the study population. Unlike sex and place of residence, early anthropometrics were not generally found to be associated with adult body mass index (BMI). However, direct relationships were found between childhood nutritional status and growth and adulthood high-density lipoprotein (HDL) cholesterol, triglycerides and fasting blood glucose. Furthermore, these relationships were not mediated by BMI. The findings were not sensitive to the metric of childhood anthropometrics, as the use of length-for-age, weight-for-age and weight-for-length all resulted in similar conclusions. These relationships demonstrate the importance of early childhood conditions for later-life outcomes. However, the lack of such relationships for blood pressure suggests that the biological links between childhood anthropometrics and various chronic diseases might vary.

Intelligence was assessed using the Standard Progressive Matrices in 316 MZ and 550 same-sex DZ twins with a mean age of 10 years in Sudan. Heritability was estimated at 0.172 and shared environmental influences at 0.596.