The marital structure of Italians living in Boston, Massachusetts, in the period 1880–1920 was studied in order to explore the integration process in the urban context. The study analyses endogamy and inbreeding, using data on 15,579 marriages from the parish books of the three Italian parishes of Boston. Endogamic rates are very high and increased in time, ranging from 93·9% to 97·3%. This correlated with the growth of the Italian community and the decline of the biased sex ratio. One parish, Our Lady of Pompeii in the South End, displays lower endogamic rates because of the reduced and scattered population attending it. The rate of consanguineous (2·33%) and isonymous (6·38%) marriages, and the coefficients of inbreeding, alpha; (0·98×10−3) and Ft (0·0159), are similar to those of north Italian populations, and lower than those for south and insular Italy. The parish of Our Lady of Pompeii shows consistently higher values than the other two parishes. Marriages between first and second cousins are the main cause of the above values in each parish. Consanguineous marriages and inbreeding increased over time, from the 1890s, and this is in general agreement, although slightly delayed, with the Italian trend.

To examine the association of environmental factors (including housing) with respiratory infections and diarrhoea in children under 5 years of age, a cross-sectional study of 403 families was conducted in a squatter settlement of Karachi. In the 2-week period before the survey prevalence of diarrhoea and respiratory infections was 14·4% and 15·0% respectively. The factors significantly associated (p>0·05) with diarrhoea in households in the multivariate analysis were: number of children under 5, regular cleaning of sewers, storage of water in small utensils and cooking inside a one room house. Five households risk factors were identified for respiratory infections: the number of children under 5, poor housing structure, increased household density, humidity inside the house less than the humidity outside house, and frequent cooking inside the house. These results suggest that children under 5 years of age in lower income areas are at additional risk to health because of poor environmental conditions.

Parental investment theory postulates that where physical condition varies significantly then birth sex ratio will be correlated with social status. Application of this theory to man remains contentious. This study examines physique, wealth, and social status in relation to the sex of live births. It reports a female-biased sex ratio in high social and economic status Nepalese. Close consanguineous marriage, intended to conserve landed wealth within related lineages, and increased female work burdens accompanying larger farm size, are proximate factors which may underlie this finding. A differential payback hypothesis is one way of explaining this pattern.

This paper proposes a causal model of sexual activity among a randomly selected sample of 305 Junior secondary school girls in Zambia. The results indicate that liberal sexual attitudes influence romantic involvement with boys. Emotional involvement is likely to result in sexual activity. Traditional courtship forms are slowly being replaced by modern patterns of courtship behaviour. Policy and programme implications are discussed.

Retrospective and prospective data collected in Cameroon were used to reassess hypotheses about how infant and early childhood mortality is affected by birth spacing and breast-feeding. These data show that: (a) a short preceding birth interval is detrimental for child survival in the first 4 months of life; (b) full and partial breast-feeding have direct protective effects on child survival in the first 4-6 months of life, with the effects of the former stronger than those of the latter; (c) early subsequent conception significantly increases mortality risks in the first 16 months of life of the index child. These findings are robust to various controls, e.g. study design, data defects, child's health conditions at/around birth, postnatal maternal and child recurrent illnesses, patterns of utilisation of health care services, and immunisation status of the child.

The data from the Demographic and Health Survey conducted in Ghana in 1988 are used to identify determinants of immunisation uptake for children under 5 years. The logistic binomial analysis shows that socioeconomic factors are significant, especially women's education and region, and that the type of prenatal care received by the mother is also important. There is a strong familial correlation of vaccination behaviours, and there is also clustering of data within enumeration areas.

This paper describes the matrimonial and reproductive behaviour of Italians who migrated to Belgium after the Second World War. Migrants were either already married, or later became married, to other Italians. Among the children of migrants, men equally chose Italian or Belgian wives but women tended to prefer Italian partners. Italian-Belgian marriages were more frequent among the better educated groups. Family size is smaller among migrants marrying after migration and in heterogamous marriages. Significant differences in birth intervals are found when marriage occurred before or after migration, between generations, and between homogamous and heterogamous marriages.

It has been suggested that parish-based reconstitution studies may underestimate the true age at marriage because they do not normally include data for emigrants who may be expected to behave differently from individuals who remain in their natal parishes. This study uses data from C18-19th parish registers of north-west Germany to estimate the difference in age at marriage between leavers and stayers. The difference is not significant for males; although that for females is significant, it is small and the consequence of failing to include migrants is likely to be negligible for most studies. However, it is shown that there is also an independent effect on age at marriage that is due to the woman's natal social (economic) status; historical demographic studies that ignore this dimension may risk confounding two different effects.

According to official census returns from Roman Egypt (first to third centuries CE) preserved on papyrus, 23·5% of all documented marriages in the Arsinoites district in the Fayum (n=102) were between brothers and sisters. In the second century CE, the rates were 37% in the city of Arsinoe and 18·9% in the surrounding villages. Documented pedigrees suggest a minimum mean level of inbreeding equivalent to a coefficient of inbreeding of 0·0975 in second century CE Arsinoe. Undocumented sources of inbreeding and an estimate based on the frequency of close-kin unions (corrected downwards to 30% for Arsinoe) indicate a mean coefficient of inbreeding of F=0·15-0·20 in Arsinoe and of F=0·10-0·15 in the villages at the end of the second century CE. These values are several times as high as any other documented levels of inbreeding. A schematic estimate of inbreeding depression in the offspring of full sibling couples indicates that fertility in these families had to be 20-50% above average to attain reproduction at replacement level. In the absence of information on the amount of genetic load in this population, this estimate may be too high