Reconstruction of human ecosystems and their stability over time provides knowledge of the processes of adaptability developed by isolated communities. Seasonality of vital events is a good indicator of the effects of different ‘traditional’ lifestyles, which in turn depend on the ecological context in which a population developed specific subsistence models. Seasonality of births reflects the cultural attitude towards the best time to conceive, in relation to work activities and loads; the latter may also affect physiological functions related to fertility. The present research concerns gross birth rates and seasonality of births and conceptions during four centuries in south-central Italy. Birth rates were between 33·0 and 36·5 per 1000. The pattern of seasonality of births and, by extension, of conceptions defines a southern-type agricultural area for the earlier periods. However, it also shows a progressive shift towards an increasing concentration of conceptions in spring–summer – namely from April to August – with a large increase in summer in the 19th century with respect to the previous periods. The new 19th century pattern is reported by Crisafulli, Dalla Zuanna & Solero (2000) as being representative of the central Adriatic region, a geographical classification to which Abruzzo can also be attributed.

Improved child health and survival are considered universal humanitarian goals. In this respect, understanding the nutritional status of children has far-reaching implications for the better development of future generations. The present study assessed, first, the nutritional status of children below 5 years using the three anthropometric measures weight-for-age, height-for-age and weight-for-height in two states of India, Kerala and Goa. Secondly, it examined the confounding factors that influence the nutritional status of children in these states. The NFHS-I data for Kerala and Goa were used. The results showed that the relative prevalence of under-weight and wasting was high in Kerala, but the prevalence of stunting was medium. In Goa, on the other hand, the relative prevalence of wasting and underweight was very high, and that of stunting was high. Both socio-economic and family planning variables were significantly associated with malnutrition in these states, but at varied levels. The study recommends more area-specific policies for the development of nutritional intervention programmes.

Analysing time-dependent independent variables requires the use of process-oriented statistical models. Yet social scientists – especially those in poor countries – have often had to use data collected at a single point in time, making their task difficult. Making several assumptions about the covariates, the present study uses survival analysis and other statistical techniques to analyse the 1996 South African population census data and examine the effects of selected independent variables on the timing of parenthood in the country. It was found that the onset of parenthood occurs late in South Africa compared with the pattern in most other African societies. While education plays a role in the postponement of parenthood within racial groups, it fails to explain the differences between African and Coloured women on the one hand, and White and Asian women on the other hand, a finding that suggests the existence of two regimes of family formation in South African society.

It has been argued that patrilineal joint family systems tend to bias family planning decisions in favour of sons. A simple model suggests that in such societies, any given son will be more highly valued by his parents (1) the fewer his brothers and (2) the earlier his birth is in the brother series. A daughter's value will be greater (1) the fewer brothers she has and (2) the earlier her birth is relative to other sisters. This study first addresses the extent of son preference as inferred from family composition data for 772 Taiwanese first-graders born in the mid-1970s in two socioeconomically distinct communities in Taipei, Taiwan. It then uses linear regression to consider whether the model criteria help account for statural variation among children in each study area when controlling for differences in measurement age, parental education and housing. With respect to family composition and gender preference, available evidence was consistent with previous surveys. While better-educated parents in the more affluent study area had significantly fewer children (p<0·0005) and were more willing to stop without a son, girls there, as in the less affluent area, were still significantly more likely than boys to belong to large sibships (p≤0·005). Evidence from mean height of males and females partially accords with hypothetical predictions. In the less affluent area, the interaction effect of male birth order and the presence of younger siblings was significantly associated with mean stature (p=0·002). Males without brothers were 2·0 cm taller than males with either an older or a younger brother (116·3 ± 0·5 cm vs 114·3 ± 0·4 cm). Males who had both younger and older brothers, but often no sisters, were about as tall, however, as those without brothers. A similar, but less pronounced, pattern was found amoung males in the more affluent area, but only among those who had sisters. These boys were also consistently shorter than boys without sisters (115·6 ± 0·6 cm vs 117·7 ± 0·6 cm; p=0·001). Patterns of mean female stature did not clearly support the hypothesis. Girls in the more affluent area were relatively tall and did not show significant variation. Results among less affluent girls showed significant contrasts, but not necessarily in the predicted direction.

The association between perception of risk of HIV infection and sexual behaviour remains poorly understood, although perception of risk is considered to be the first stage towards behavioural change from risk-taking to safer behaviour. Using data from the 1998 Kenya Demographic and Health Survey, logistic regression models were fitted to examine the direction and the strength of the association between perceived risk of HIV/AIDS and risky sexual behaviour in the last 12 months before the survey. The findings indicate a strong positive association between perceived risk of HIV/AIDS and risky sexual behaviour for both women and men. Controlling for sociodemographic, sexual exposure and knowledge factors such as age, marital status, education, work status, residence, ethnicity, source of AIDS information, specific knowledge of AIDS, and condom use to avoid AIDS did not change the direction of the association, but altered its strength slightly. Young and unmarried women and men were more likely than older and married ones to report risky sexual behaviour. Ethnicity was significantly associated with risky sexual behaviour, suggesting a need to identify the contextual and social factors that influence behaviour among Kenyan people.

The final estimate of South Africa's population as of October 1996 from the first post-apartheid census by Statistics South Africa was lower (40·6 million) than expected (42 million). The expectation of a total population of 42 million was largely based on results of apartheid projections of South Africa's population. The results of the last apartheid census in South Africa in 1991 had been adjusted such that it was consistent with results modelling the population size of South Africa. The discrepancy between the final estimate of the 1996 census and that expected from the modelling described above, and the departure by Statistics South Africa from previous practice of adjusting the census results to be consistent with demographic models, has generated controversies regarding the accuracy of the final results from the 1996 census. This study re-examines levels and differential in fertility in South Africa from recent evidence in order to assess whether or not the fertility inputs in projections of South Africa's population during the apartheid era overestimated fertility.

The social environment and exposure to life challenge affect a person's physical and emotional well-being. The present research uses a population-based study of the elderly in Taiwan to elaborate the cumulative physiological costs – as reflected in biological markers of risk factors known to have adverse consequences for health – of challenge and unfavourable position in social hierarchies and networks. Overall, biological markers of risk among the elderly are similar in Taiwan and the United States. However, male and female Taiwanese elderly are at lower risk for illness associated with indicators of DHEA-S, while women are at higher risk for illness associated with elevated blood pressure, and men at lower risk for illness associated with total/HDL cholesterol, and glycosylated haemoglobin. There are strong and statistically significant effects of position in social hierarchy (education) and challenge (recent widowhood and a perception of high demands) on an index of cumulative risk (allostatic load). Membership in social networks and participation in social activities have expected, but not statistically discernible, effects.

The purpose of this study was to investigate whether the well-established relationship between parity and birth weight is affected by the sex composition of siblings, especially for male newborns. Subjects were 856 male and 862 female newborns who weighed at least 2500 g at birth, who were born after 37 completed weeks of gestation, who obtained an Apgar score of 7 or higher, who had the same biological parents as all other children in the sibship, and who lived in the same household. Information on birth weight was collected from hospital records. Results showed that male newborns with older brothers weighed less than male newborns with older sisters. In contrast, the weight of female newborns with older brothers did not differ from the weight of female newborns with older sisters. One explanation of these results is that maternal immunoreactivity to some male-specific feature of the fetus affects prenatal development and consequently reduces birth weight in males. The relation between older brothers and birth weight may have theoretical significance for behavioural variables.

This study examines the relationship between blood pressure and the religious practices of Kuwaitis as members of a Muslim society. Religious variables were measured via a sociocultural questionnaire. Blood pressure measurements were taken with a sphygmomanometer. Non-opportunistic samples were taken from 223 Kuwaitis. The difference in religious commitment between Muslim Sunnis and Muslim Shiites was examined using a t-test. Matrix correlation was used to examine the relationship between religious commitment and some other variables. Multiple regression was conducted to determine the effect of religiosity on blood pressure, as well as statistically controlling for other variables such as body mass index, socioeconomic status, smoking, gender and age. It was found that both systolic and diastolic blood pressure were affected by religious commitment and religious activities.