The problem of involuntary childlessness and its effect on marital happiness has been studied in an investigation involving interviews with 75 childless couples and a matched control of 75 couples with children. Marital happiness in various phases of the couple's relationship is plotted; in childless women this is seen to fall to its lowest ebb during the phase immediately before the problem is brought to the attention of the doctor, whilst in men it occurs whilst waiting for the medical diagnosis to be made. It seems that whilst childless marriages in themselves are not necessarily less happy than those with children (though all the childless couples interviewed had sought to change their situation by seeking medical help) such marriages are based on a different equilibrium from that of couples with children. In childless marriages there is often closer communication between the partners and a greater degree of communis opinio. People with children are sometimes over-careful in their approach to those without children. Attitudes and behaviour with regard to fidelity are seen to differ; the childless couples interviewed were less permissive in this respect than those with children. Alternatives in the form of artificial insemination, adoption, careers and pets are briefly considered.

The influence of parental age at birth, and parity, was studied in a series of 48 dyslexic boys. It was concluded that both increased paternal and maternal age contributes to a greater incidence of the condition. The similarity to the age distributions of chromosomal aberrations and some mutation defects suggests some genetic implication. The findings thus favour a biological rather than environmental element in the aetiology.

Aiming to further explore possible underlying causes of the recent remarkable stagnation and relative decline in American heights, this paper describes the result of analysis of the commercial US Sizing Survey (2002). Heights are correlated positively with income and education among both white males and females while Body Mass Index (BMI) is correlated negatively among females, as in other samples. In contrast to much of the literature, this paper considers geographic correlates of height such as local poverty rate, median income and population density at the zip code level of resolution. After adjusting for confounding factors that influence height such as income and education, population density is found to be strongly and negatively correlated with height among white men, but less so among white women. The effect on BMIs less convincing. Other ethnic groups are not analysed in detail because of the small number of observations available. Local economic conditions as measured by median income, unemployment and poverty rate do not have a strong correlation with height or BMI after adjusting for individual income and education.

Using retrospective data from the Urban Integration Survey conducted in 2001 in Nairobi, Kenya, on a sample of 955 women and men aged 25–54, this paper compares factors influencing entry into union formation for men and women. The analysis uses event history methods, specifically Cox Proportional Hazards regression, stratified by age cohort and run separately by sex. The results indicate that delay in union formation is more pronounced for women than for men. Cohabitation without formal marriage is the prominent form of union, especially among the younger generation, and appears to have increased. For men, the timing of union is more dependent upon human capital acquisition than on cultural factors. These findings show that the marriage search model, which was first applied in Western countries, can also hold in cities of developing countries. Nonetheless, neither the search model nor the integration or the independence models apply to women's union formation, which very few exogenous factors can explain.

In order to evaluate the mental health aspects of voluntary sterilization for family planning purposes, WHO initiated in 1978 a multi-centre prospective controlled study. A total of 926 healthy women with at least two living children, who requested sterilization (interval, post-partum or post-abortion), and 924 controls using other methods of contraception, were selected for a prospective investigation which included pre-operative and post-operative (6 weeks, 6 months, and 1 year) standardized assessment of mental state and a range of variables related to physical health and psychosexual functioning. Although pre-operatively a high proportion of subjects in both index and control groups reported minor non-specific psychiatric symptoms the percentage of women meeting defined criteria of psychiatric disorder was low to moderate (less than 15%) in all centres except Cali (26%). In all centres the pre-operative rates of psychiatric disorder were somewhat higher in the sterilization groups than in the control groups, and in two centres (Cali and Chandigarh) this difference was statistically significant. Thus, the data indicate that women choosing sterilization for birth control tend to show pre-operatively more psychiatric disturbance than their control counterparts who opt for other methods of contraception.

The role of religion in contraceptive use is an issue of significant debate. This study employed the 1990 and 2008 Nigeria Demographic and Health Survey data to examine differences and similarities in the influence of religious affiliation on non-use of modern contraceptives in Nigeria over the last two decades. The results suggest that a significant increase has occurred in the level of awareness of modern contraceptives in Nigeria over the last two decades, but that non-use remains very high. Religion could not independently predict non-use of modern contraceptives in 1990. Women of Islam and Traditional religions were more likely to have never used or not to be using modern contraceptives compared with Catholics and Protestants in 2008 (p<0.05). This can be explained by their poorer socioeconomic status relative to Catholics and Protestants. Therefore, improving women's socioeconomic status is an imperative in the promotion of modern contraception in Nigeria. Education and employment are critical in this regard and adherents of Islam and Traditional religions require special attention.

Using the nationally representative sample of about 15,000 Add Health respondents in Wave III, the hypothesis is tested that masculinity–femininity in adolescence is correlated with sexual orientation 5 years later and 6 years later: that is, that for adolescent males in 1995 and again in 1996, more feminine males have a higher probability of self-identifying as homosexuals in 2001–02. It is predicted that for adolescent females in 1995 and 1996, more masculine females have a higher probability of self-identifying as homosexuals in 2001–02. Masculinity–femininity is measured by the classical method used by Terman & Miles. For both time periods, the hypothesis was strongly confirmed for males: the more feminine males had several times the probability of being attracted to same-sex partners, several times the probability of having same-sex partners, and several times the probability of self-identifying as homosexuals, compared with more masculine males. For females, no relationship was found at either time period between masculinity and sex of preference. The biological mechanism underlying homosexuality may be different for males and females.

Excess weight is becoming widespread in Spain due to changes in nutritional habits and lifestyles. Previous studies on this issue have focused on specific Spanish regions, subpopulations or relatively short time spans. This study analysed sex, age and cohort trends in the prevalence of adult overweight and obesity over the last two decades by applying a demographic methodology. Data came from the Spanish National Health Surveys that were held between 1987 and 2006. The respondent's demographic characteristics and self-reported height and weight were aggregated to a single dataset in order to analyse changes in weight and BMI by age and sex, over time and within and between quasi birth-cohorts. After correcting for sample bias and coding errors a total sample of about 100,000 subjects aged 20–79 was obtained. The results show that between 1987 and 2006 adult males and females increased their average weight by 8.2% and 2.8%, respectively. While among younger adults this is partly explained by height increases, prevalence in excess weight increased among 50- to 79-year-old males. Persons of the same 10-year age group but of a more recent 10-year quasi birth-cohort had a BMI that was 0.2–0.8 points higher. BMI increases were lower for women and mainly affected 60–79 year olds. In fact, even decreases were observed for 40- to 49 and 50- to 59-year-old women. Potential explanatory factors are discussed.

A time-dependent model of the probability of sexual intercourse, where the probability increases as the time from last intercourse increases, can produce waves in the expected frequency of sexual intercourse on the various dates of the menstrual cycle. These waves occur when the time-dependent model is linked with a period of abstinence, such as is usually found in most societies during the time of the menses. Previously, such waves have been attributed to cyclic hormonal changes in women without considering the full implication of a time-dependent model of sexual intercourse.

A sample of 35 South African Negro albinos and a normally pigmented matched control group have been studied for adjustment problems and attitudes towards this inherited condition. The results showed that although the albinos appeared to be as well adjusted as the controls, significantly more of the albino group had adjustment problems of a physical nature indicated by psychosomatic symptoms. Attitudes were found to be reasonably positive. One common local misconception was revealed: that albinos do not die but disappear or ‘vanish away’. There was very little understanding of the cause, mode of inheritance or the problems associated with albinism. It is concluded that relevant genetic counselling should be offered to the Negro albinos to enable them to understand their condition, its implications and the myths which surround it. Because albinism is so common in South Africa the education of the community in this connection is also desirable.

Understanding the social and cultural contextual determinants of sexual behaviour of adolescents and young adults is an essential step towards curtailing the spread of HIV. This study examined the effects of one cultural factor, ethnicity, on sexual abstinence, faithfulness, condom use at last sex, and risky sex among young people in Zimbabwe. Data from the cross-sectional, population-based 2005–06 Zimbabwe Demographic and Health Survey were used. Net of the effect of sociodemographic and social–cognitive factors, and using multinomial logistic regression, ethnicity was found to have a strong and consistent effect on sexual behaviour among youth. In addition, the study found that there were ethnic-specific and within-gender differences in sexual behaviour, for both men and women. Shona youth were more likely to be abstinent than Ndebele youth. Compared with Shona youth, Ndebele youth were more likely to have engaged in risky sex. However, Ndebele men were more likely have used condoms at last sex, compared with Shona men. For both men and women, sexual behaviour was more socially controlled. School attendance and religion exerted protective effects on sexual abstinence. For men only, those living in rural areas were less likely to be faithful and more likely to have engaged in risky sexual behaviour than those living in urban areas. The study attests to the fact that ethnic norms and ideologies of sexuality need to be identified and more thoroughly understood. In addition, the study provides evidence that in order to promote safe and healthy sexuality among young people in Zimbabwe, cultural, social and gender-specific approaches to the development of HIV prevention strategies should be seriously considered. Current success in the Abstinence, Being faithful and Condom use (ABC) approach could be strengthened by recognizing and responding to cultural forces that reproduce and perpetuate risky sexual behaviours.

Humans exhibit sex differences in competitiveness, sensation seeking and risk-taking attitude, which are required in sports. These attributes are often linked to prenatal testosterone (PT) exposure. The second-to-fourth digit length ratio (2D:4D) is an indicator of PT exposure. A lower 2D:4D indicates higher PT exposure and vice versa. Males generally have a lower 2D:4D than females. Sensation- and/or thrill-seeking behaviours have also been found to be negatively associated with 2D:4D. Boxing and judo are considered to be high-risk sports. Voluntary participation in judo/boxing in contrast to aerobics can be guided by such behaviours and thus have an association with lower 2D:4D. This cross-sectional study included 167 female students from a military academy in Wrocław, Poland. Of them, 119 had voluntarily chosen aerobic exercise, and 48 opted for judo/boxing. Height, weight and second and fourth digit lengths were measured. Physical fitness was assessed using Eurofit tests. The two groups showed similar physical fitness and body size. However, the judo/boxing group had significantly lower mean 2D:4D values than the aerobics group. It is proposed that voluntary choice of participation in a sport discipline by women could be linked to the ‘organizational’ effect of intrauterine testosterone exposure during prenatal growth.

Endeavours to control urogenital schistosomiasis on Unguja Island (Zanzibar) have focused on school-aged children. To assess the impact of an associated health education campaign, the supervised use of the comic-strip medical booklet Juma na Kichocho by Class V pupils attending eighteen primary schools was investigated. A validated knowledge and attitudes questionnaire was completed at baseline and repeated one year later following the regular use of the booklet during the calendar year. A scoring system (ranging from 0.0 to 5.0) measured children’s understandings of schistosomiasis and malaria, with the latter being a neutral comparator against specific changes for schistosomiasis. In 2006, the average score from 751 children (328 boys and 423 girls) was 2.39 for schistosomiasis and 3.03 for malaria. One year later, the score was 2.43 for schistosomiasis and 2.70 for malaria from 779 children (351 boys and 428 girls). As might be expected, knowledge and attitudes scores for schistosomiasis increased (+0.05), but not as much as originally hoped, while the score for malaria decreased (−0.33). According to a Kolmogorov–Smirnov test, neither change was statistically significant. Analysis also revealed that 75% of school children misunderstood the importance of reinfection after treatment with praziquantel. These results are disappointing. They demonstrate that it is mistaken to assume that knowledge conveyed in child-friendly booklets will necessarily be interpreted, and acted upon, in the way intended. If long-term sustained behavioural change is to be achieved, health education materials need to engage more closely with local understandings and responses to urogenital schistosomiasis. This, in turn, needs to be part of the development of a more holistic, biosocial approach to the control of schistosomiasis.

The associations between cigarette smoking before and during pregnancy and maternal body size (pre-pregnancy weight status, end of pregnancy weight status, weight gain during pregnancy) and newborn size (birth weight, length, head circumference, arcomial circumference), as well as birth modus, were tested in 7803 single full-term births in Vienna. Nicotine consumption before and during pregnancy was found to be associated with smaller and lighter newborns, although maternal weight status and weight gain during pregnancy was signi.cantly higher in smokers. Furthermore, a higher incidence of Caesarean sections was found in smokers. A reduction in the number of daily smoked cigarettes was associated with a lower percentage of low weight newborns (<2500 g).

The Standard Progressive Matrices test was standardized in Estonia on a representative sample of 4874 schoolchildren aged from 7 to 19 years. When the IQ of Estonian children was expressed in relation to British and Icelandic norms, both demonstrated a similar sigmoid relationship. The youngest Estonian group scored higher than the British and Icelandic norms: after first grade, the score fell below 100 and remained lower until age 12, and after that age it increased above the mean level of these two comparison countries. The difference between the junior school children and the secondary school children may be due to schooling, sampling error or different trajectories of intellectual maturation in different populations. Systematic differences in the growth pattern suggest that the development of intellectual capacities proceeds at different rates and the maturation process can take longer in some populations than in others.

The purpose of this study was to show the differences in the mortality rates of children from Catholic and Lutheran families in 19th century Poznań, and to elucidate the causes of these differences. Data from Catholic and Lutheran parish death registers were used. The infant death rate (IDR), neonatal and postneonatal death rates and life table biometric functions were calculated and causes of deaths were characterized. The worst child mortality values (IDR=394.4; neonatal and postneonatal death rates, respectively, 117.1 and 277.4; e0=16.14 years; Crow's Index=2.47) were obtained for the poor Catholic Parish of St Margaret. The lowest infant and neonatal and postneonatal death rates were observed to have occurred in the Catholic Parish of St Maria Magdalena situated in the city's more affluent central area (mortality rates, respectively, 269.9, 93.1 and 176.9; e0=24.63 years; Crow's Index=0.96). The widest range of differences with regard to death rates was found for the Lutheran Parish of St Cross (the infant, neonatal and postneonatal death rates were, respectively, 293.1, 99.1 and 193.9; e0=28.03 years; Crow's Index=0.92). The St Cross Parish encompassed a fairly large area of the city characterized by varying ecological conditions. Among infants and young children from the three studied populations a high frequency of deaths due to infectious diseases, diarrhoeas, dysenteries and tuberculosis were observed. Differences in the mortality of children from Catholic and Lutheran families in 19th century Poznań resulted from ecological conditions, among which water played the most important role, rather than from religious differences.

Research designs to study alcohol use and abuse have included twin, adoption and family history/high risk studies. Results have consistently implied a genetic factor in the aetiology of alcohol abuse. However, less research has been conducted in search of environmental factors. This study uses kinship structure in a large national dataset (the National Longitudinal Survey of Youth) to estimate (using DeFries–Fulker analysis) the extent of the shared genetic, non-shared genetic, shared environmental and non-shared environmental influences on alcohol use. The NLSY kinship sample contained 3890 pairs of cousins, half-siblings, full-siblings and twins between the ages of 14 and 21 in the initial year of the survey (1979). Estimates of heritability (h2) and shared environment (c2) were small to moderate for the entire dataset for both light drinking and heavy drinking behaviour, with h2 estimates slightly higher in each case. Non-shared genetic measures of self-esteem and locus of control accounted for a significant portion of the remaining variance in heavy drinking behaviour. Race and gender patterns showed c2 and h2 estimates that were also small to moderate for both light and heavy drinking behaviour. Significant non-shared effects were found for the White group for heavy drinking behaviour, and for male pairs for both heavy and light drinking behaviour. Additionally, implications and future directions are discussed.

This study examines the delay between first marriage and first live birth in China among a sample of women who married between 1980 and 1992. Most couples in China only use contraception after the first child is born. Most sample women had their first child within 2 years of marriage. However, there are significant rural–urban differences in the first birth interval, indicating that there was most probably deliberate fertility regulation after marriage among many urban couples. Survival analysis shows that place of residence, level of education, age at first marriage and marriage cohort affect the first birth interval.

Child marriage has significant negative impacts, not only for girls, but also for a range of development outcomes. This study aimed to assess, in a more detailed way than done so far, the magnitude of the relationship between child marriage and total fertility in multiple countries representing diverse settings. Data from the most recent Demographic and Health Surveys in the fifteen countries of interest were used. Analysis was restricted to a subsample of women aged 35–49 years in order to capture completed fertility. Poisson regression was conducted to estimate the impact of each additional year of early marriage on the total number of births women have, controlling for selected sociodemographic characteristics. Counterfactual analyses were carried out to estimate the reduction in the number of children that women would have over their lifetime in the absence of child marriage. Controlling for socioeconomic and other characteristics, girls who marry as children have more children over their lifetime than women marrying after the age of 18. Nationally, across fifteen countries, the reduction in total fertility from ending child marriage ranges from 0.24 to 1.06 children per woman. The simulated change in total fertility that would result from ending child marriage tends to be higher in countries that have a higher incidence of child marriage.

Responses of 44 vasectomized voluntarily childless men and 51 vasectomized fathers were compared on the California Psychological Inventory, the Bowerman Scale of Marital Satisfaction and a questionnaire. The childless felt negatively stereotyped, but there were no differences between the parents and childless on marital satisfaction, reported childhood happiness or level of psychological adjustment. There were differences in modes of adjustment, with the childless seemingly less tied to tradition, more inclined to experiment and showing more capacity for independent thought than the parents. The findings suggested that childlessness may be a viable, healthy lifestyle, not determined by or associated with personal or social pathology.