This paper examines factors that may predispose unmarried and unemployed out-of-school youth to risky sexual behaviour. Data for analysis were derived from the Behaviour Surveillance Survey carried out in Kenya in late 2002. A total of 6129 male and female unmarried and unemployed out-of-school youth in the age range 15–24 years were successfully interviewed. However, for this paper only a sample of 3961 comprising sexually experienced youth in the 12 months preceding the survey was used. Methods of analysis included descriptive statistics and multinomial logistic regression. Results for males indicate that factors associated with low and high risk were whether they had fathered a child, district of residence and frequency of alcohol use, while current age and age at first sexual debut stood out for those with low risk alone. For females the district of residence and age of partner at sexual debut were the factors that predisposed them to low-risk sexual behaviour, while for high risk the district of residence, current age and ever being pregnant were significant. The results indicate that for these youth, contextual and probably social factors appear to be the main determinants of risky sexual behaviour for both males and females. The findings also support those of other studies that link risky sexual behaviour among youth, especially males, to alcohol consumption. Programmes for intervention therefore need to focus on these aspects. There is also a need for studies that can look at district-specific factors for more focused interventions.

Synchronous with the decline in fertility that took place in the post-war period in the Netherlands, patterns of birth seasonality changed as well. In this paper seasonal fluctuations in fertility in the Netherlands are examined using population register data for the period 1952 to 2005. The peak in births has changed from spring to summer and subsequently to August/September, thereby shifting from the European to the American pattern. The seasonal shift can be attributed to parity-specific changes. Before the transition, birth seasonality did not differ much between the different parities. In the transition period from higher to low fertility, differences between parities increased which persist up to today. At present, the overall seasonality pattern is determined by first births. Moreover, birth seasonality varies by maternal age. The findings stimulate the discussion on the role of planning as a cause of birth seasonality.

While the ‘immigrant health paradox’ posits better health behaviours and outcomes for immigrants upon arrival to the US, research suggests that this advantage may deteriorate over time. This study analysed the relationship of acculturation and breast-feeding initiation and duration among a sample of predominantly Latina, low-income women in the US. The four measures of acculturation included: mother’s nativity (foreign born vs US born), mother’s parents’ nativity (foreign born vs US born), years of US residence (<8 years vs ≥8 years) and a dichotomous measure of language acculturation adapted from three items on Marin’s acculturation scale (preferred language spoken at home, reading language and writing language) as exclusive use of native language versus non-exclusive use (mixed or English only) (Marin et al., 1987; Marin & Gamba, 1996). Final multivariable models showed that mothers who exclusively used their native language were more likely to initiate breast-feeding as well as breast-feed for longer duration compared with mothers with non-exclusive use, whereas years of US residence and mother’s nativity were not significantly associated with breast-feeding initiation or duration. Mother’s parents’ nativity also emerged as a significant predictor of breast-feeding duration, both within final models for immigrants and across study participants. Programmes providing nutrition education to low-income women may wish to consider the role of language as an important determinant of breast-feeding. The role of mother’s parents’ nativity on breast-feeding practices deserves exploration in future studies, as the cultural practices taught by family members born outside the US may exert strong pressure within immigrant families now living in the US.

The socioeconomic milieu has benefits and drawbacks for determining level of nutrition. The Indian population provides an excellent example of nutrition-driven adaptation. The present paper deals with the relationship between BMI (body mass index) and traditional occupation and process of adaptation among adult males of Central India. Anthropometric data collected by the Anthropological Survey of India on stature, sitting height and weight of 6663 adult males belonging to 22 castes were used for computation of BMI and Cormic index. The caste groups earning their living as labourers are found to be shortest (157·4±6·5 cm), and the caste group practising priesthood are tallest (168·6±6·6 cm). The prevalence of chronic energy deficiency is found to be highest (72%) among castes earning their living as daily wage labourers. The ANOVA on Cormic index and BMI suggests that people within the same occupational group are more homogeneous than those from different occupational groups. The t test also supports the homogeneity of the same occupational group.

This study examines the short- and long-term effects of war-induced and war-unrelated migration on fertility outcomes using data from two peri-urban municipalities of Greater Luanda in Angola. In the short term, results from multi-level discrete-time logistic regression models indicate that net of other factors, war-unrelated migration is associated with a lower probability of birth than war-induced migration in a given year. Similar results are obtained when the effects of migration are lagged by a year. At the same time, the effects of war-triggered migration do not differ significantly from those of not migrating in a given year but are statistically significant when the effects of migration are lagged by a year. In the long term, the effects of migration experience on cumulative fertility are negligible and not statistically significant net of demographic and socioeconomic variables. Interpretations of the results are offered in the context of Angola and their broader implications are reflected on.

Recent research has highlighted the risk of HIV infection for married teenage women compared with their unmarried counterparts (Clark, 2004). This study assesses whether a relationship exists, for women who have completed their adolescence (age 20–29 years), between HIV status with age at first marriage and the length of time between first sex and first marriage. Multivariate analysis utilizing the nationally representative 2004 Cameroon Demographic and Health Survey shows that late-marrying women and those with a longer period of pre-marital sex have the highest risk of HIV. Although women in urban areas overall marry later than their rural counterparts, the positive relationship between age at marriage and HIV risk is stronger in rural areas. The higher wealth status and greater number of lifetime sexual partners of late-marrying women contribute to their higher HIV risk. Given that the age at first marriage and the gap between first marriage and first sex have increased in recent years, focusing preventive efforts on late-marrying women will be of much importance in reducing HIV prevalence among females.

The ‘helpers at the nest’ hypothesis suggests that individuals who are not currently reproducing often help kin by caretaking and thereby increase their inclusive fitness. Using a large scale historical dataset (Integrated Public Use Microdata Series sample of 1910; n=13,935), the hypothesis is tested that childless couples are more likely to fulfil such a role by taking care of a niece or nephew, but not a parent, than couples with children. Childless couples were significantly more likely to take care of a niece or nephew than couples with children. In contrast, couples with children and childless couples did not differ in caretaking of parents. Childless couples were also more likely to have more and younger nieces/nephews in their home than couples with children.

This paper examines the role of observed contextual factors like topography, development and literacy on severe malnutrition among social groups in rural Maharashtra based on the Reproductive and Child Health District Level Household Survey (RCH-DLHS) Round II (2002–04) data. Multilevel modelling techniques were applied in order to examine the district-wise variations in severe malnutrition associated with the characteristics of the places (contextual effects), as the relationships with the type of people (compositional effects) have already been well established. The results show that developmental aspects such as road connectivity, community literacy, toilet facilities and household standard of living contribute positively to the status of severe malnutrition. Also, the scheduled tribe, aboriginal underprivileged group are more at risk of severe malnourishment due to a lack of proper development, poor awareness about maintaining and enhancing the nutritional value of food and lack of hygiene and sanitation as compared with the scheduled castes, another aboriginal group.

No information is currently available on the marriage patterns of German-speaking communities of the South Tyrol area. The aim of this study is to investigate the reproductive isolation of four South Tyrolean mountain villages during the 19th century. Data about 3953 marriages were drawn from existing pedigrees and completed with data from the parish registers of the studied villages to calculate the following indicators: age at marriage, endogamy, inbreeding from dispensations and from isonymy and repeated pairs of surnames among couples. The results show high levels of endogamy (78–87%) and an elevated age at marriage in all the studied villages. The percentages of consanguineous marriages (10–33%) vary considerably but result overall in relatively low inbreeding values (α 0·0015–0·0036; Ft 0·0098–0·0138). Levels of endogamy are consistent with the geographic characteristics of the area, while inbreeding values are lower than those observed in previous studies on Alpine communities. This is due to a low frequency of marriages between close relatives, probably related to the peculiar demographic and cultural characteristics of the studied populations that differentiate them from neighbouring Italian-speaking villages.

In a recent article in this journal, Lynn et al. (2007) found a high correlation between average national IQs and achievement test scores in 67 countries and concluded ‘The correlation is so high that national IQs and educational achievement appear to be measures of the same construct.’ The author finds here the data do not support this conclusion.

Unquestionably, aggregate-level correlations are in most cases higher than individual-level correlations. For example, in the National Longitudinal Survey of Youth (NLSY) in the United States, the correlations are 0·487 between adolescent IQ and log-transformed adult income, 0·449 between years of schooling and adult income and 0·626 between years of schooling and IQ (N=6064). The corresponding country-level correlations are 0·815, 0·816 and 0·788 (N=125 countries).