There is increasing evidence that age at menarche has decreased in Europe and the United States during the last century and in Japan over the last several decades. Data from a community-based survey conducted in two rural counties of Anhui Province in China indicate a similar, downward secular trend in age at menarche for Chinese women. The present study shows the mean age at menarche decreased by 2·8 years, from 16·5 to 13·7, over an approximate 40-year time interval. This rapid decrease in age at menarche may partly be due to better nutrition and living standards reflected by the improved socioeconomic standards experienced in China over the past few decades. To test this hypothesis, a number of determinants of age at menarche were assessed; year of birth, literacy status, county of residence, amount of physical labour, general health status, pesticide exposure before age at menarche, and drinking water source were all found to be associated with age at menarche.

Fisher (1930) presented both theoretical and empirical results concerning genetic influences on fertility. Since then, only sparse research has been done on the genetics of fertility, although more sophisticated methodogy and data now exist than were available to Fisher. This paper presents a behavioural genetic analysis of age at first intercourse, accounting for genetic, shared environmental, and selected non-shared environmental influences. The data came from the nationally representative National Longitudinal Survey of Youth (NLSY). A newly developed kinship linking procedure was used that identifies links for cousins, half-siblings, full-siblings and twins in the NLSY. The results suggest a genetic influence in the overall dataset, and also among whites and in male–male and opposite-sex pairs. Genetic influences were extremely small or non-existent for blacks and for female–female pairs. Shared environmental influences were small for most subsets of the data, but moderate for female–female pairs. Two specific non-shared environmental influences – self-esteem and locus of control – were ruled out as accounting for any meaningful variance, although other general sources of non-shared environmental influence appear potentially important. Analysis of selected samples from upper and lower tails suggested that genetic influences are important in accounting for both early and late non-virginity. These findings are consistent with work reported by Miller et al. (1999), who used molecular genetic methods. Generally, these findings support the existence of genetic influences and implicate non-shared environmental influences as being important determinants of the timing of loss of virginity among US adolescents and young adults.

From 1971 to 1984, the Israeli Defence Forces administered two tests unaltered that qualify as IQ tests. These were the Matrices and the Instructions tests. The former is an adaptation of Raven's Progressive Matrices, similar to the original in that there are clusters with progressive difficulty and an escalation of difficulty throughout the test. The raw score range is from 4 to 35. The Instructions test is adapted from the old US Army Alpha Instructions Test and is described as an Otis-type verbal test. It includes 21 open-ended instructions. Typical items: write the last letter of the word which is the opposite of black; write the third letter of the largest word among the following four words; find the word beginning and ending with the same letter and write that letter. There are similar questions using numbers rather than letters. Both tests are timed, and most subjects do not complete either. There is no penalty for wrong answers (Col. Moshe Even-Chen, personal communication, 14 March 1990; Gal, 1986, pp. 79 and 95; Judy Goldenberg, personal communications, 4 March 1991 and 25 April 1993).

From March 2007 to March 2008 a cross-sectional study was conducted in Qatar to estimate the prevalence of consanguinity among Qataris and to assess their knowledge of the risks and their attitudes towards the practice. A secondary objective was to test the acceptability of sixteen Likert-style questions within the Qatari population. Face-to-face interviews using a 70-item structured questionnaire were conducted by three native Arabic-speaking medical students with 362 Qatari employees. Where consanguinity existed between the employee's parents, a diagram of the consanguinal relationship (phylogram) was completed. The response rate was 93%. By phylogram, 22% of participants reported a cousin relationship between their parents (consanguinal relationship) and another 15% reported that their parents were from the same tribe (affinal relationship). With respect to their own marital decision, 68% of the respondents had been married at least once. By phylogram, 35% of these reported a consanguineous relationship (first marriage), 9% reported only an affinal relationship and 56% reported that they were not married to a blood relative. Results on the sixteen Likert-style attitude questions were stratified by consanguinity status of parents and of self. In the stratification by consanguinity status of parents the top five attitudes differed by group but there appeared to be more similarity between the consanguinal and only tribal groups. Attitudinal results were stratified by sex. Results showed that the males had a stronger belief in several of the attitudes than females with the exception of causation of genetic abnormalities and health problems. The phylogram was shown to collect more detailed and explicit data than hard-coding. With respect to knowledge, the results showed that knowledge was imperfect with high proportions of participants not knowing that consanguinity has been implicated in autosomal recessive diseases such as thalassaemia, inborn errors of metabolism, deafness, anomalies of the extremities and specific congenital heart defects. Additionally, a sizeable proportion of the participants did not know that a more distant cousin marriage (e.g. third cousin) theoretically could be a less genetically risky choice to potential offspring than a closer cousin marriage (half-first cousin). These results indicate that more effort needs to be made in developing public health strategies to improve the population's understanding of the cost-benefit analysis involved in contracting consanguineous marriages given the goal of healthy offspring.

This study assessed the role of mother’s religious affiliation in child immunization status of surviving children 12 months of age and older in Nigeria, using data from the 2003 Nigeria Demographic and Health Survey (NDHS). Guided by two competing hypotheses – the ‘characteristics hypothesis’ and the ‘particularized theology hypothesis’ – variations in the risks of child immunization in Nigeria were examined using logistic regression analysis. The results indicate that religion plays a role in the risk of non-immunization; religion was not associated with the risk of partial immunization; however, religion was significantly associated with the reduced risk of full immunization.

Consanguineous marriage is the union of individuals having at least one common ancestor. The present cross-sectional study was done in order to illustrate the prevalence and types of consanguineous marriages in the Syrian Arab Republic. Data on consanguineous marriages were collected using a simple questionnaire. The total number of couples in this study was 67,958 (urban areas: 36,574 couples; rural areas: 31,384 couples) from the following provinces: Damascus, Hamah, Tartous, Latakia, Al Raqa, Homs, Edlep and Aleppo. In each province urban and rural areas were surveyed. Consanguineous marriage was classified by the degree of relationship between couples: double first cousins (F=1/8), first cousins (F=1/16), second cousins (F=1/64) and beyond second cousins (F<1/64). The coefficient of inbreeding (F) was calculated for each couple and the mean coefficient of inbreeding (α) estimated for the population of each province, stratified by rural and urban areas. The results showed that the overall frequency of consanguinity was 30.3% in urban and 39.8% in rural areas. Total rate of consanguinity was found to be 35.4%. The equivalent mean inbreeding coefficient (α) was 0.0203 and 0.0265 in urban and rural areas, respectively. The mean proportion of consanguineous marriages ranged from 67.5% in Al Raqa province to 22.1% in Latakia province. The α-value ranged from 0.0358 to 0.0127 in these two provinces, respectively. The western and north-western provinces (including Tartous, Lattakia and Edlep) recorded lower levels of inbreeding than the central, northern and southern provinces. The overall α-value was estimated to be about 0.0236 for the studied populations. First cousin marriages (with 20.9%) were the most common type of consanguineous marriages, followed by double first cousin (with 7.8%) and second cousin marriages (with 3.3%), and beyond second cousin was the least common type.

Intimate partner violence (IPV) is a global public health and gender problem, especially in low-income countries. The study focused on verbal abuse, physical abuse and abuse by restricting food provision to wives by their husbands by victim and perpetrator characteristics, emphasizing the socioeconomic context of rural Bangladesh. Using a cross-sectional household survey of 4411 randomly selected married women of reproductive age, the study found that a majority of the respondents are exposed to verbal abuse (79%), while 41% are exposed to physical abuse. A small proportion (5%) of the women had suffered food-related abuse. Risk factors observed were age of the wife, illiteracy (of both victims and perpetrators), alcohol misuse, dowry management, husband's monetary greed involving parents-in-law, and wife's suspicions concerning husband's extramarital affairs. Well-established risk factors for wife abuse, along with dowry and husband's monetary greed, have a relatively high prevalence in rural Bangladesh.

Most analyses of the contraceptive decision-making in which couples engage are based on the reports of only one partner, usually the female partner. This study uses information from the 2006 National Couples Survey conducted in the US, which was obtained from both partners in intimate heterosexual relationships to investigate the relative impact of the male and female partner's method preferences on the type of method they use together. It also investigates the extent to which differences in power between the partners, measured on multiple dimensions, may weigh the decision-making process toward one partner or the other. The results suggest that men's and women's method preferences are both significantly related to the couples' method choice. Further, there is no evidence of a significant gender difference in the magnitude of these relationships, although women in married and cohabiting relationships appear to have greater power over method choice than women in dating relationships. The analysis also finds that structural power as measured by relative education and income affects partner differences in the relationship between preferences and method choice, but is more important for married and cohabiting couples than for dating couples. In contrast, relationship-based power sources, including relative commitment and relative relationship alternatives, have significant effects only for dating couples.

The relation between women’s timing of menarche and father absence was examined in a national probability sample of Great Britain (NATSAL 2000; N>5000). Current body mass index (as a proxy for childhood weight) was examined as a potential mediator of this relationship, along with the potential moderating role that siblings (e.g. number of older brothers) had on this relationship. As in a number of previous studies, an absent father (but not an absent mother) during childhood predicted an earlier age of puberty (i.e. an early menarche). There was no evidence that weight mediated this relationship or that siblings moderated it. Both a lower body mass index and more siblings (e.g. more younger sisters and brothers) were independent predictors of a later timing of puberty. The results confirm that certain psychosocial factors (i.e. father absence; presence of siblings) may affect the timing of sexual maturation in adolescent girls.

This paper traces the development of policies dealing with HIV/AIDS in Botswana from their beginning in the late 1980s to the current programme to provide population-wide anti-retroviral therapy (ARV). Using a variety of source material, including long-term ethnographic research, it seeks to account for the failure of Western-inspired approaches in dealing with the pandemic. It does this by looking at the cultural and institutional features that have created resistance to the message and inhibited effective implementation. The negative response to the first educational campaign stressing condom use is described and contextualized in terms of Tswana ideas of morality and illness. Nor, as was initially expected, did the introduction of free ARV therapy operate to break the silence and stigma that had developed around the disease. Take-up was very slow, and did not operate to encourage widespread testing. In 2003, key policymakers in Botswana began to argue for a break with the AIDS ‘exceptionalism’ position, with its emphasis on voluntarism, confidentiality and the human rights of patients. This resulted in routine testing being introduced in 2004. This links to a major argument running through the paper which is that the failure of policy cannot be attributed solely to the nature of local populations. Western cultural assumptions about ‘good practice’ also require critical examination.

It remains unclear whether the frequency of marital coitus does in fact decline universally across the life course, what shape that decay normally takes, and what best accounts for it: increasing marriage duration, women’s age or age of their partners. Using cross-sectional Demographic and Health Survey (DHS) data of 91,744 non-abstaining women in their first marriage, a generalized linear model is used to determine if there is a consistent pattern in the life course pattern of degradation in the frequency of marital coitus. Datasets were drawn from nineteen countries in Asia, Africa and the Americas. Use of very large samples allows proper disentangling of the effects of women’s age, husband’s age and marital duration, and use of samples from multiple countries allows consideration of the influence of varied prevailing fertility regimes and fertility-related practices on life course trajectories. It is found that declining coital frequency over time seems a shared demographic feature of human populations, but whether marriage duration, wife’s age or husband’s age is most responsible for that decline varies by country. In many cases, coital frequency actually increases with women’s age into their thirties, once husband’s age and marriage duration are taken into account, but in most cases coital frequency declines with husband’s age and marital duration.

This study presents a multivariate behavioural genetic analysis of the relationship between education, intelligence and age of first birth. Analyses investigated the mediational role of education in explaining the relationship between intelligence and age of first birth at both the phenotypic and behavioural genetic level. The data come from the National Longitudinal Survey of Youth (NLSY), a nationally representative survey that included genetically informative full- and half-sibling pairs (n=1423 pairs). Respondents were aged 14 to 22 when contacted in 1979. Heritability estimates were 0·32, 0·50 and 0·06 for IQ, education and age of first birth, respectively. Shared environment estimates were 0·35, 0·23 and 0·20 respectively. Common genetic and shared environmental factors were substantial in explaining the relationship between intelligence and education, and also education and age of first birth. Education partially mediated the relationship between intelligence and age of first birth only in the phenotypic analyses. After considering the genetic and shared environmental factors that influence all three variables, evidence for mediation was less convincing. This pattern of results suggests that the apparent mediational role of education at the phenotypic level is in fact the result of underlying genetic and shared environmental influences that affect education, IQ and age of first birth in common.

In all societies for which data exist, there is seasonality in the incidence of births, a major cause of which in the UK appears to be season ality in sexual activity.

In contrast to the findings of Cowgill for earlier periods in other places, there has recently been in Great Britain a greater degree of seasonality in legitimate than in illegitimate births and in upper-class than in lower-class births.

Part of the explanation of the change in illegitimate seasonality could be the recent increase in the numbers of illegitimate births. The greater seasonality of upper-class births could be due to longer and more mobile holidays.

Of all the controversial issues surrounding IQ tests, few have generated more heat and less light than the question whether different groups in our society differ in average IQ. Those who study, and find evidence of, such differences believe that they are addressing a legitimate scientific issue and one whose implications, however unpalatable they may be, society ignores at its peril. Their critics insist that the question has no intrinsic scientific interest whatsoever, and conclude that those who study it are either naive, deceiving themselves or only too happy to find justification for their own comfortable position within an unjust and unequal society. In the case of sex differences in IQ scores, at least, one could argue that both sides have got it largely wrong. With one exception, there is relatively little social or political implication in such differences as there are. More importantly, however, arguments will be presented against the critics' view that such research is of no intrinsic scientific interest. On the contrary, it has already helped to answer some important scientific questions about the nature of IQ, and has the potential to answer more. Unfortunately, those who engage in such research have usually failed to see this.

A number of authors have identified multiple concurrent sexual partnerships by both men and women to lie at the root of the HIV/AIDS epidemic in sub-Saharan Africa. This study applies multilevel models to Demographic and Health Survey data collected during 2003–2008 in 20 sub-Saharan African countries to examine the influence of social and cultural context on involvement with multiple sexual partnerships in the region, above and beyond the effects of individual characteristics. The findings provide support for the ecological argument that health behaviours are shaped and determined by societal conditions, in addition to the effects of individual and household characteristics. Involvement with multiple sex partners is most prevalent in societies in which sexual norms are widely permissive and where polygyny is common. Individual autonomy is substantial and attitudes towards sexuality are more liberal among men and women who live in communities in which sexual norms are widely permissive. Men and women who are most likely to have multiple sex partners in the sub-Saharan region are those who initiated sexual activity earlier and those who have the individual attributes (e.g. young age, urban residence, education, media exposure and working for cash and away from home) that bring to them more rights and/or decision-making autonomy, but not necessarily more financial resources and economic security (mostly among women). On the other hand, involvement with multiple partners is determined by cultural norms (i.e. permissive sexual norms) and social change (i.e. mass education, expansion of cash employment). The findings suggest a number of opportunities for more effective policy and programmatic responses to curb the prevalence of multiple partnerships in sub-Saharan Africa.

Across 85 countries around the world, Voracek (2004) found a significant positive relation between estimated national intelligence (IQ) and national male and female suicide rate. The relation was not attenuated when countries’ per capita Gross Domestic Product (GDP) and type of national IQ estimation were statistically controlled. Independently, investigating the total national suicide rate only, Lester (2003) arrived at the same conclusion. These two findings are consistent with a corollary of de Catanzaro’s (1981) evolutionary theory of human suicide, namely that a threshold intelligence is necessary for suicidality and that intelligence and suicide mortality should thus be positively related. Here, further evidence for this hypothesis is bolstered by focusing on suicide rates of the elderly. Across 48 Eurasian countries, estimated national IQ was significantly positively related to national suicide rates of people aged 65 years and over. This new ecological-level finding survived statistical controlling for a set of seven variables (type of national IQ estimation, national GDP, stableness and recency measures for suicide rates, and rates of adult literacy, urbanization and Roman Catholics), which thus are not confounding factors for the relation of intelligence and suicide mortality. Based on ecological data, the threshold IQ for suicidality is predicted to be 70 or slightly over, an estimate that is consistent with various suicidological observations.

This paper analyses the levels and trends of childhood mortality in urban Bangladesh, and examines whether children’s survival chances are poorer among the urban migrants and urban poor. It also examines the determinants of child survival in urban Bangladesh. Data come from the 1999–2000 Bangladesh Demographic and Health Survey. The results indicate that, although the indices of infant and child mortality are consistently better in urban areas, the urban–rural differentials in childhood mortality have diminished in recent years. The study identifies two distinct child morality regimes in urban Bangladesh: one for urban natives and one for rural–urban migrants. Under-five mortality is higher among children born to urban migrants compared with children born to life-long urban natives (102 and 62 per 1000 live births, respectively). The migrant–native mortality differentials more-or-less correspond with the differences in socioeconomic status. Like childhood mortality rates, rural–urban migrants seem to be moderately disadvantaged by economic status compared with their urban native counterparts. Within the urban areas, the child survival status is even worse among the migrant poor than among the average urban poor, especially recent migrants. This poor–non-poor differential in childhood mortality is higher in urban areas than in rural areas. The study findings indicate that rapid growth of the urban population in recent years due to rural-to-urban migration, coupled with higher risk of mortality among migrant’s children, may be considered as one of the major explanations for slower decline in under-five mortality in urban Bangladesh, thus diminishing urban–rural differentials in childhood mortality in Bangladesh. The study demonstrates that housing conditions and access to safe drinking water and hygienic toilet facilities are the most critical determinants of child survival in urban areas, even after controlling for migration status. The findings of the study may have important policy implications for urban planning, highlighting the need to target migrant groups and the urban poor within urban areas in the provision of health care services.

Rates of social mobility are some of the most revealing indicators of a society's character. In any society there is a tendency for privileged groups to try to close ranks, preserve their advantages and pass them on to their children, but the arguments of social justice, economic efficiency and social stability all suggest that these tendencies towards closure and inherited privilege should be curbed. In western liberal societies the dominant version of social justice is perhaps the one that advocates equality of opportunity: those with equal effort and talent should be equally rewarded whatever their class, sex, age, race or religion. Economic efficiency likewise requires that workers should be paid according to their actual productivity rather than to ascribed (and economically irrelevant) characteristics such as their race or sex. And theories of social order hold that the blocking of legitimate aspirations for social and economic advancement will be a potent source of social dissent and conflict (see Goldthorpe, 1980; Heath, 1981). On all three counts the opportunities open to members of ethnic minorities are of interest, but sociologically the third has particular interest for whereas within native white society failure to secure upward social mobility may lead to individual responses—to personal frustration and stress—an ethnic minority which experiences discrimination and blocked careers as a shared grievance is to that extent more likely to respond with collective protest and militant group action.

Secondary analysis of the trends and correlates of consanguinity in the Palestinian Territories was conducted using data from two separate surveys in 1995 and 2004. The analysis was conducted on ever-married women aged 15–54 who were asked about their relation to their husband in both surveys. A total of 16,197 women in 1995 and 4971 women in 2004 were successfully interviewed. Consanguinity was found to be widely practised in the Palestinian Territories with rates of total consanguinity reaching 45% of all marriages in 2004. Analysis was conducted with the data from the two surveys combined and this indicated that consanguinity was significantly decreasing with time after controlling for other variables. Age of the women, their age at marriage, region and locality type they lived in and their standard of living were all found to be significant predictors of consanguinity. The education level of the women was not found to be significant. After controlling for the survey year, women’s labour force status was also found to be a non-significant predictor of consanguinity. Although consanguinity was found to be significantly decreasing slowly with time after controlling for other variables, the future trends of consanguinity are not known due to the unstable political situation in the territories, which could have a direct effect on marriage patterns.