For modern Western societies with a regime of monogamy, it has recently been demonstrated that the socioeconomic status of men is positively associated with being or having been married. This study aims to compare marriage patterns (if a person has been married at least once) for cultures with a tradition of monogamy and polygyny. As no worldwide data on polygyny exist, religion was used as a proxy for monogamy (Christians) vs polygyny (Muslims). The analyses were based on 2000–2011 census data from 39 countries worldwide for 52,339,594 men and women, controlling for sex, sex ratio, age, education, migration within the last 5 years and employment. Overall, a higher proportion of Muslims were married compared with Christians, but the difference in the fraction of married men compared with married women at a certain age (the ‘marriage gap’) was much more pronounced in Muslims than in Christians, i.e. compared with Christians, a substantially higher proportion of Muslim women than men were married up to the age of approximately 31 years. As expected for a tradition of polygyny, the results indicate that the socioeconomic threshold for entering marriage is higher for Muslim than Christian men, and Muslim women in particular face a negative effect of socioeconomic status on the probability of ever being married. The large ‘marriage gap’ at a certain age in Muslim societies leads to high numbers of married women and unmarried young men, and may put such polygenic societies under pressure.

This study aimed to contribute to the evidence on the timing of sexual debut in young people in sub-Saharan African countries. Data were extracted from 34 nationally representative surveys conducted in the region between 2006 and 2014. The study sample comprised unmarried women (n=167,932) and men (n=76,900) aged 15–24 years. Descriptive techniques and Cox proportional regression models were used to estimate the timing of sexual debut, and Kaplan–Meier hazard curves were used to describe the patterns of sexual debut in each country by sex. For the countries studied, sexual debut for both women and men occurred between the ages of 15 and 18 years, with median ages of 16 for women and 17 for men. Overall, education and household wealth provided significant protection against early sexual debut among women, but the reverse was found among men for wealth. Women in rural areas, in female-headed households and in Central, South and West Africa reported higher hazards of early commencement of sexual activity than their counterparts in urban, male-headed households and East Africa. However, the impact of these variables on male sexual debut did not follow a consistent pattern. Varied timing, as well as country-specific risk factors associated with sexual debut for young women and men across sub-Saharan Africa, were identified. Sexual health programmes and interventions for young people may require different approaches for young women and men.

The aim of this paper was to establish whether the differences in the risks of union dissolution between cohabitors and non-cohabitors in Uganda have converged over time using event history data. Data were collected in 2013 from 1200 women in central Uganda using retrospective methods. Of these, 839 provided information on three types of first union: women who married directly (without first cohabiting), those who married following cohabitation and those who were still cohabiting. The data were analysed using decrement lifetable analysis. Though the analysis indicated a small difference in the timing of first union dissolution for women who married directly, no evidence was found that the difference in the risk of union dissolution between cohabitors and non-cohabitors had converged over the 9-year period following first union. Women’s union/marriage status, number of living children in a union, parental union status and birth cohort were found to significantly influence the timing of union dissolution. Overall, the rate of union dissolution was fairly high, regardless of type of union.

Medical male circumcision has been recommended by the World Health Organization as part of a comprehensive approach to HIV prevention. Zimbabwe is one of the fourteen sub-Saharan countries that embarked on the Medical Male Circumcision (MMC) programme. However, the country has not yet met male circumcision targets. This paper examines the predictors of male circumcision in Zimbabwe. A cross-sectional survey was conducted on 784 men aged 15–35 years in Harare, Zimbabwe. Negative log-log logistic regression analysis was used to determine the predictors of male circumcision. The main predictors of circumcision were age, employment status, ever tested for HIV, approval of HIV testing prior to circumcision, knowledge about male circumcision and attitudes towards male circumcision. By and large, participants had good knowledge about male circumcision and viewed HIV prevention with a reasonably positive attitude. The identification of these predictors can be used to scale up the demand for male circumcision in Zimbabwe.

Several studies report that women exposed to intimate partner violence (IPV) are less likely to use contraception, but the evidence that violence consistently constrains contraceptive use is inconclusive. One plausible explanation for this ambiguity is that the effects of violence on contraceptive use depend on whether couples are likely to have conflicting attitudes to it. In particular, although some men may engage in violence to prevent their partners from using contraception, they are only likely to do so if they have reason to oppose its use. Using a longitudinal follow-up to the Indian National Family Health Survey (NFHS-2), conducted among a sample of rural, married women of childbearing age, this study investigated whether the relationship between IPV and contraceptive use is contingent on whether women’s contraceptive intentions contradict men’s fertility preferences. Results indicate that women experiencing IPV are less likely to undergo sterilization, but only if they intended to use contraception and their partners wanted more children (Average Marginal Effect (AME)=−0.06; CI=−0.10, −0.01). Violence had no effect on sterilization among women who did not plan to use contraception (AME=−0.02; CI=−0.06, 0.03) or whose spouses did not want more children (AME=−0.01; CI=−0.9, 0.06). These results imply that violence enables some men to resolve disagreements over the use of contraception by imposing their fertility preferences on their partners. They also indicate that unmet need for contraception could be an intended consequence of violence.

A gender gap has been found in mathematics (boys outperform girls) that has prevailed across countries for many decades. Whether this gap results from nature or nurture has been hotly debated. Using the evidence of PISA 2003 and the gender equality index of 2003, some researchers have argued that an improvement in gender equality reduces the gender gap in mathematics. This study used five waves of country-level PISA data and, controlling for country fixed effects, found no evidence to support this argument. Furthermore, individual data for PISA 2012 and the multilevel data model were used. The conclusion drawn also does not support the argument. In fact, the relationship between gender equality and the gender gap in mathematics vanished after PISA 2003.

Over recent decades, economic living conditions have dramatically improved in South Korea, which now represents one of the most developed nations. At the same time, its twin in the North remains one of the poorest countries on earth. Thus, the Korean peninsula represents a unique historical experiment that allows for study of the effects of environment on human development under a variety of ceteris paribus cultural, genetic and climatic conditions. Previous studies comparing the biosocial performances of the two Koreas have focused on indicators such as weight, height, mid-upper arm circumference and age at menarche. The purpose of the present study was to investigate longevity based on the number of centenarians living in the two Koreas by drawing on censuses implemented around 1925 and 2010. The study found that North Korea had some 0.7 centenarians per one million persons in 1925, and this rate moderately improved to 2.7 around 2010. Conversely, rates skyrocketed in South Korea from 2.7 in 1925 to 38.2 around 2010. This suggests that the rate of centenarians in North Korea around 2010 corresponds to that of South Korea in 1925, suggesting a chronological lag in delayed human development of some 85 years. The prevalence of centenarians is fourteen times higher in contemporary South Korea compared with the North – broadly confirming previous biosocial studies on the two Koreas and two Germanies reporting improved human development in market-oriented systems compared with socialist ones.

This study assessed caste differentials in family-level death clustering, linked survival prospects of siblings (scarring) and mother-level unobserved heterogeneity affecting infant mortality risk in the central and eastern Indian states of Jharkhand, Madhya Pradesh, Odisha and Chhattisgarh. Family-level infant death clustering was examined using bivariate analysis, and the linkages between the survival prospects of siblings and mother-specific unobserved heterogeneity were captured by applying a random effects logit model in the selected Indian states using micro-data from the National Family Health Survey-III (2005–06). The raw data clustering analysis showed the existence of clustering in all four states and among all caste groups with the highest clustering found in the Scheduled Castes of Jharkhand. The important factor from the model that increased the risk of infant deaths in all four states was the causal effect of a previous infant death on the risk of infant death of the subsequent sibling, after controlling for mother-level heterogeneity and unobserved factors. The results show that among the Scheduled Castes and Scheduled Tribes, infant death clustering is mainly affected by the scarring factor in Jharkhand and Madhya Pradesh, while mother-level unobserved factors were important in Odisha and both (scarring and mother-level unobserved factors) were key factors in Chhattisgarh. Similarly, the Other Caste Group was mainly influenced by the scarring factor only in Odisha, mother-level unobserved factors in Jharkhand and Chhattisgarh and both (scarring and mother-level unobserved factors) in Madhya Pradesh. From a government policy perspective, these results would help in identifying high-risk clusters of women among all caste groups in the four central and eastern Indian states that should be targeted to address maternal and child health related indicators.

Economic conditions have dramatic influences on fertility. This paper evaluates the effect of the 2008 ‘Great Recession’ in the UK on first birth rate, which is the fertility behaviour most susceptible to external economic conditions. The key aim of the study was to assess the effect of the recession on fertility by individual-level characteristics, enabling variation in responses to economic hardship to be observed. Data were from the nationally representative UK Household Longitudinal Study (UK-HLS). Cumulative transition models were used to model the probability of first birth for women between the ages of 17 and 30 in three UK birth cohorts. The effect of the recession was captured using direct measures (local unemployment rates and individual unemployment status) and a pre-/post-comparison, capturing indirect effects. In general, higher birth rates were observed among more disadvantaged women compared with advantaged groups. The effect of the recession was disaggregated by social strata; the overall effect was counter-cyclical although at a slower rate among disadvantaged women.