Consanguineous marriage – marriage between relatives – has received a great deal of attention as a potential risk factor for many adverse health outcomes. The present cross-sectional study was done in order to illustrate the prevalence and types of consanguineous marriages among Iranian Georgians living in Frydoonshahr (Isfahan province, central Iran). Data on consanguineous marriages were collected using a simple questionnaire. The total number of couples in this study was 646. Consanguineous marriage was classified by the degree of relationship between couples. First cousin marriages (14.2%) were the most common type of consanguineous marriages, followed by second cousin (7.0%), beyond second cousin (1.5%) and first cousin once removed (0.6%). The mean inbreeding coefficient (α) was calculated as 0.0104 for the population. The present study shows that the study population, as other Iranian populations, has a high level of consanguinity.

This paper examines the impact of childhood malnutrition on schooling performance in rural Bangladesh. The results reveal that malnourished children are less likely to enrol in school on time and achieve an age-appropriate grade by 26 percentage points and 31 percentage points, respectively. Other important determinants of schooling outcomes include infrastructure and education level of parents. One major contribution of this paper is the control for the endogeneity of malnutrition status, which otherwise might lead to bias estimates.

It is now widely recognized that a decentralized approach to the control of parasitic infections in rural sub-Saharan populations allows for the design of more effective control programmes and encourages high compliance. Compliance is usually an indicator of treatment success, but cannot be used as a measure of long-term benefit since re-infection will be strongly influenced by a number of factors including the social ecology of a community. In this paper qualitative and quantitative methods are used to identify and understand the structural and behavioural constraints that may influence water contact behaviour and create inequalities with respect to Schistosoma re-infection following anti-helminth drug treatment. The research is set in a community where participant engagement has remained uniformly high throughout the course of a 10-year multidisciplinary study on treatment and re-infection, but where levels of re-infection have not been uniform and, because of variations in water contact behaviour, have varied by age, sex and ethnic background. Variations in the biomedical knowledge of schistosomiasis, socioeconomic constraints and ethnic differences in general attitudes towards life and health are identified that may account for some of these behavioural differences. The observations highlight the benefits of understanding the socio-ecology of control and research settings at several levels (both between and within ethnic groups); this will help to design more effective and universally beneficial interventions for control and help to interpret research findings.

This paper models the proximate determinants of height, weight and haemoglobin concentration of over 25,000 Indian children using data from the National Family Health Survey-3. The effects of public and private health care service utilization, food consumption patterns and maternal health status on child health were investigated in a multidisciplinary framework. Methodological issues such as potential endogeneity of explanatory variables and the appropriateness of combining height and weight as the body mass index were tackled. The results from models for children's heights and weight showed beneficial effects of child vaccinations against DPT, polio and measles, and negative effects of not utilizing government health facilities. The models for children's haemoglobin concentration indicated beneficial effects of food consumption patterns and treatment against intestinal parasites. The results provide several insights for improving child health in India.

Marital isonymy is frequently used to estimate inbreeding and the repeated pairs method is useful to investigate whether the population under examination has subdivisions. These methods can also be applied to registers, such as population censuses, where both spouses' surnames are noted. In this paper, the 1795 census for Córdoba province is analysed. Numerically speaking, Spanish and mixed-race people are the major ethno-social groups in the register. In order to estimate inbreeding, the isonymic method was applied to both groups, at provincial and at parish level. To appreciate to what extent the parishes were genetically isolated, Wright's Fst was also calculated. The repeated pairs method was also used for both groups to assess if population subdivision existed in the units under study. Finally, to evaluate whether the subdivision based on surnames reflected the ethno-social stratification, the same method was used considering the two groups together. At the provincial scale, both groups displayed low inbreeding and micro-differentiation, although the former was higher for the Spanish and the latter for mixed-race groups, which could indicate a more marked conjugal selectivity in the Spanish. At the parish scale, preferences for isonymic spouses were not pronounced either in Spanish or in mixed-race groups; in the Spanish group population subdivision prevailed, with the opposite occurring in the mixed-race group. The estimations from repeated pairs, taking the two groups together, indicated that for the studied populations the surnames do not allow the two groups to be differentiated into isolated reproductive units.

The purpose of this study was to investigate intergenerational transmission of reproductive behaviour in Botswana. The major source of data was the 2001 Botswana AIDS Impact Survey where a nationally representative random sample of men and women aged 10–64 years was selected using a stratified two-stage probability sample design. Covariates in the analysis include age, education, marital status, religion, age at first birth, residence, duration at residence and contraceptive use. The main analytical technique is linear regression. The results indicate that the reproductive behaviour of older generations has a significantly positive influence on the reproductive behaviour of the subsequent generation, but does not affect the subsequent generation homogenously. The effect appeared much stronger for women who initiated childbearing at an older age, for women who had never been to school, and for the cohort aged 50–59 years. These findings suggest that number of siblings, as a reproductive behaviour determinant, may very well have confounded previous reproductive behaviour analyses in Botswana. The study draws attention to the importance of the effect of origin family size in determining reproductive behaviour outcomes in Botswana.

The aim of this study was to identify the characteristics of individuals who formed exogamic marriages in the Friuli region (north-east Italy) during the second half of the 19th century. Logistic regression models were devised to measure the influence of the determinants of exogamic marriage, taking into account not only variables related to context but also spouses' economic, social and cultural characteristics. The determinants of exogamic marriage differ for men and women, and also vary by region due to differences in geographical mobility and size of the marriage market. The majority of exogamic spouses belong to one of two categories: either older individuals, often, especially in the case of men, with a previous marriage; or the upper social classes.

The increasing greying of India's population raises concerns about the welfare and health status of the aged. One important source of information of health status of the elderly is the National Sample Survey Rounds on Morbidity and Health Care Expenditure. Using unit-level data for 1995–96 and 2004, this paper examines changes in reported health status of the elderly in India and analyses their relationship with living arrangements and extent of economic dependency. It appears that even after controlling for factors like caste, education, age, economic status and place of residence, there has been a deterioration in self-perceived current health status of the elderly. The paper argues that, although there have been changes in the economic condition and traditional living arrangements – with a decline in co-residential arrangements – this is not enough to explain the decline in reported health status and calls for a closer look at narratives of neglect being voiced in developing countries.

This study investigates current contraceptive use among Malawi couples. The data examined are from the 2001 Malawi Diffusion and Ideational Change Project (MDICP). The aim of the study is to explore whether contraceptive use among married couples is affected by the couple's concerns about HIV/AIDS and couple's age difference. Contraceptive use was found to be associated with the couple's HIV concern and family planning goals. There is no significant association between spousal age difference and contraceptive use. The findings are important for future work on the connection of marital concerns about HIV/AIDS with contraceptive behaviours, especially the use of condoms, and for informing HIV preventive strategies in marriage.

Research is needed to understand the role of religion in family planning dynamics, particularly in societies where the views of religious leaders can be an important influence on the reproductive decisions of individuals. This paper attempts to describe the factors associated with approval of contraception among religious leaders in Pakistan. The data are taken from the 1999–2000 Survey of Perception of Religious Leaders about Population Welfare. Regression modelling shows that whether or not religious leaders approve of family planning is associated with their views on the ideal family size, their level of religious education, the specific religious sect to which they belong, their own knowledge and use of family planning, their exposure to television and the region of the country in which they live.

Using a sample of 2090 father and son pairs, the regional variation in height, weight and body mass index (BMI) with intra- and inter-generational migration within Britain was examined. Highly significant regional differences in means were found only for fathers. The overall mean height difference between regions ranged from about 2.7 cm to 3.1 cm, with the tallest fathers being found in the East & South-East region and the shortest in Wales. The variation in mean weight between regions was less significant, with the difference between the heaviest region (West Midlands) and lightest (South-West) being about 3.5 kg. For BMI the highest mean was in the North and Wales and the lowest in the South-West (difference of about 1 kg m−2). Intra-generational migrants were, on average, significantly taller than non-migrants for both fathers (+1.4 cm) and sons (+2 cm), but BMI was only significant in fathers, with migrant fathers, on average, having a lower BMI. There were no significant differences in weight between geographically mobile groups for either fathers or sons. Differentiating between regional in- and out-migration revealed that in the fathers' generation in-migrants were taller, on average, in six of the nine regions. The tallest in-migrants among fathers came into the North region; the tallest out-migrants were from Yorkshire & Humberside and the shortest were from Scotland. The largest positive gain on fathers' height was in the West Midlands region and Scotland, while negative effects were found in the Yorkshire & Humberside, East Midlands and East & South-East regions. For sons in-migrants were taller in all regions except Wales, with the largest differences between in-migrants and non-migrants being in the South-East and South-West. For out-migrants, the tallest sons came from Wales, while the shortest came from the East Midlands region. The North, East Midlands, East & South-East and West Midlands regions were net gainers, while Wales and Scotland were net losers. For BMI among fathers, in-migrants were of lower BMI than non-migrants. For out-migrant fathers, the North-West and South-West regions were the only two regions showing positive values, with the largest negative values being found in the East Midlands and Yorkshire & Humberside. The net effect of migration indicated that the largest gains were in the East Midlands and Yorkshire & Humberside regions and the largest losses were in Scotland and Wales. The inter-generational migration for BMI showed that in-migrating sons into the North-West and Wales had higher BMI than sedentes, while in-migrants into Yorkshire & Humberside were lower in BMI. In all regions out-migrants had lower BMI than non-migrants. The net effect of migration revealed that six of the nine regions were net gainers, while the Yorkshire & Humberside region was a net loser.

Although desired family size is often different from actual family size, the dynamics of this difference are not well understood. This paper examines the patterns and determinants of the difference between desired and actual number of children (unmet fertility desires) among women aged 15–49 years using pooled data from the 1990, 1999 and 2003 Nigeria Demographic and Health Surveys (NDHSs). The results show that more than two-thirds of the sample have unmet fertility desires (18.1% have more while 52.4% have fewer than desired). It was found that early and late childbearing increased the odds of unmet fertility desires. Also, women with low levels of education, from poor households, rural residents as well as those who had experienced child death were at a higher risk of unmet fertility desires in the multivariate context. The study highlights the policy and programme implications of the findings.

Many studies have shown that females smile more than males do in social situations. The present study extends this research by examining a large sample of high school yearbook photographs. In addition to assessing the degree of smiling, ratings were obtained of the following traits for each photograph: hair length, hair colour, masculine–feminine appearance and physical attractiveness. Results reconfirmed earlier research showing that females smile more than males do while they are being photographed. Other findings were that smiling was positively correlated with hair length, femininity and physical attractiveness for females but not for males. When a multivariate analysis was performed, none of these traits predicted smiling in males, and only femininity was significant in predicting smiling in females. Although social learning theories of smiling can account for some of these findings, a recently proposed neurohormonal theory seems to best explain why femininity is related to smiling in females but not in males.

Consanguinity has been shown to increase homozygosity and to reduce genetic variation in a group, which may protect against the expression of recessive genes that can lead to genetic disorders. Consanguineous marriages are practised widely in Kuwait. The major aim of this study is to delineate the association of consanguineous marriages with congenital disabilities in different Kuwaiti population subcultures. A total of 9104 married Kuwaiti females aged 15–79 years from different backgrounds were selected at ten primary health care centres from six governorates in Kuwait. Data were collected using a questionnaire and analysed with chi-squared tests. The data indicate significant differences in the occurrence of genetic diseases in consanguineous couples' offspring (4.88%) compared with those of non-consanguineous couples (4.13%) (p<0.002). The results also show significant differences in frequencies of genetic/environmental diseases in consanguineous couples' offspring (8.59%) compared with those of non-consanguineous couples (8.23%) (p<0.005). No significant differences between the two groups regarding environmental diseases were observed. A higher frequency of genetic diseases was found in first- (6.97%; p<0.001), second- (6.78%; p<0.001) and third-cousin (6.46%; p<0.022) couples' offspring compared with those of non-consanguineous couples. The frequency of congenital disabilities in the offspring of couples from consanguineous marriages (2.9%) is higher than that in the offspring of non-consanguineous marriages (2.3%). But this difference is not significant at the 0.05 level. First-cousin marriages have the highest frequency (3.5%) of congenital disabilities compared with other kinds of marriages (2.1–2.3%). Differences across groups are significant (p<0.036). Significant differences are found for first-cousin couples in both physical (2.37; p<0.042) and mental (0.74; p<0.037) disabilities compared with non-consanguineous couples. No significant differences were observed in deafness and blindness disabilities. The data show no significant differences between second- and third-cousin and non-consanguineous couples in physical, mental or deafness and blindness disabilities. There are no significant differences in the percentages of offspring with congenital disabilities in consanguineous and non-consanguineous marriages across sub-population groups for the total of four types of congenital disability.

This study applied a gender perspective to establish some of the anthropometric, body composition, health and socio-cultural determinants of active ageing. The variable ‘active ageing’ (presence/absence) was created based on cognitive and disability/illness/physical functioning, subjective health, satisfaction with life and productive activity performed, and used in predictive models to establish its relationship with anthropometric variables, physical health indicators and educational level. The sample consisted of 456 home-living individuals (169 men and 287 women; age range 54–75 years) from Madrid and Toledo in Spain. The women had a higher prevalence of obesity than the men (37.6% vs 29.0%), significantly greater fat accumulation in the abdominal area and worst perceived health (p=0.003). The frequency of active agers is higher in men than in women (38.4% vs 21.9%; p<0.001). Men and women were found to have distinctive ageing patterns. Health factors condition the presence of active ageing in women, while education factors are also relevant in men.

Data for Raven's Progressive Matrices are reported for a sample of 6290 6- to 17-year-olds in Taiwan. The Taiwanese obtained a mean IQ of 109.5, in relation to a British mean of 100. There was no difference in mean scores of boys and girls at age 7 years. At age 10 years girls obtained significantly higher scores than boys, and at ages 13 and 16 years boys obtained significantly higher scores than girls. There was no sex difference in variance at age 7 years. At ages 10, 13 and 16 years variance was significantly greater in boys.

In a recent paper in this Journal, I offered hypotheses on the offspring sex ratios of women infected with the parasite Toxoplasma gondii, and on the offspring sex ratios of people who are carriers of hepatitis B virus (HBV) (James, 2008). Subsequent research suggests that these hypotheses need amending. A detailed account of the amendments is given elsewhere in a specialized journal (James, 2010a). Here they are summarized.

Garenne (2009) presented data on the sex ratio of a present birth by the numbers of previous brothers and sisters. In unisexual sibships, the probability of a further girl increases with the number of previous girls; and the probability of a further boy increases with the number of previous boys. Garenne noted that there is an asymmetry in that the effect is stronger with regard to girls than boys. He was uncertain of the cause of this. Here I suggest a potential solution to this problem. Garenne also seems to imply that parental reproductive stopping rules cause heterogeneity of sex ratios. I suggest that they may reveal it – but do not cause it. Moreover, I suggest that the effects of such stopping rules may be counter-intuitive.

The aim of this study was to estimate the prevalence of, and socio-demographic factors associated with, overweight and obesity in Botswana. A cross-sectional survey was conducted in 2007 using a multistage sampling method to select a representative sample of 4107 men and 4916 women aged 20–49 years. Logistic regression analysis was used to identify the socio-demographic factors associated with overweight and obesity. Mean BMI values for men and women were 21.7 kg/m2 and 24.4 kg/m2, respectively. Both overweight and obesity levels were higher among women than men. Overall, 23% of women were overweight compared with 13% of men. Obese women constituted about 15% compared with only 3% of men. However, 19% of men were underweight compared with 12% of women. The main socio-demographic factors associated with overweight and obesity were being older, living in a city/town, being married and having attained higher levels of education, and these relationships were statistically significant at the 5% level. Although over-nutrition is prevalent among adult female Batswana, underweight remains an important public health problem for males. Programmes and other interventions aimed at concurrently addressing both under-nutrition and overweight need to be developed.

Using a sample of 2090 father and son pairs, the extent of intra- and inter-generational social mobility (migration between social classes) was examined over a 42-year period in a British cohort in relation to height, weight and body mass index (BMI). The mean height difference between the highest and lowest social class decreased from about 4 cm in the fathers' generation to about 3 cm in the sons' generation, indicating a decline in heterogeneity in height between classes. For fathers downward intra-generational social mobility ranged between 11% and 18% while between 16% and 26% were upwardly mobile; for sons 15% were downwardly mobile and 21% upwardly mobile. On average downwardly mobile fathers were shorter by between 0.1 cm and 0.7 cm while upwardly mobile fathers were taller by, on average, 0.6 cm to 1.7 cm. For sons, the downwardly mobile were on average 0.7 cm shorter and the upwardly mobile 0.8 cm taller. For weight and BMI there were no consistent relationships with intra-generational mobility in either the fathers' or sons' generations. Inter-generationally, between 18% and 19% of sons were downwardly mobile and between 39% and 40% were upwardly mobile; the downwardly mobile were shorter by about 0.9 cm and the upwardly taller by between 0.6 cm and 1.2 cm. Sons with higher BMI were more likely to be inter-generationally downwardly mobile.