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The structure of kinship links in a given population at a given time is the result of several past demographic events that shaped the population during its evolution. Many populations display particular kinship structures due to the occurrence of specific events at some point in their history, such as founder effects. Using genealogical data retrieved from the BALSAC population register, the BALSAC-RETRO genealogical database and the Early Quebec Population Register, this study focuses on the genetic consequences of the demographic settlement and expansion experienced by the Quebec population over the last four centuries. A total of 2,223 ascending genealogies were reconstructed for the purpose of this study. These genealogies have an average depth of 9.3 generations and go back as far as the early seventeenth century. Measures of kinship show that 98 percent of all pairs of subjects share at least one distant common ancestor. Virtually all genealogies (99.2 percent) contain at least one French founder. Overall, nearly 87 percent of the current gene pool is explained by French founders who came mainly from the provinces of Normandie, Ile-de-France, Aunis, Poitou, and Perche during the seventeenth century. [ABSTRACT FROM AUTHOR]

This study addresses the impact of family history of disease and family history of longevity on cause-specific mortality in a large population-based cohort. We identified a cohort of 464,494 people born between 1830 and 1984 from the Utah Population Database, a resource of linked genealogy, vital statistics, and disease data. To be eligible, a cohort member must have lived at least 65 years and died between 1904 and 2002. We measured familial disease risks using the familial standardized mortality ratio (FSMR), and familial longevity using familial excess longevity (FEL). For each of the leading causes of death in the U.S., we constructed a nested casecontrol study using cohort members dying of a specific cause (cases) and individually matched cohort members who remained at risk at the time of the cases' deaths (controls). Our results indicate that family histories of cause-specific mortality greatly affect risk of death from the same cause, especially for heart disease, cancer, and diabetes. However, familial excess longevity is associated with decreased risks of almost all causes of death, suggesting that whatever factors link kin survival, an important component is the familiality of longevity within their extended family. The one major disease for which familial longevity confers no substantial protection is cancer, suggesting that there may be some antagonism between genetic mechanisms that protect against aging and those that protect against cancer. [ABSTRACT FROM AUTHOR]

Fertility patterns may be useful markers for rates of biological aging. From historical data for the population of Quebec (taken in the "Registre de population du Québec ancien", at the University of Montreal), we examine the effects of reproduction on longevity from evolutionary and sociodemographic perspectives. Using Cox hazard models on 1,923 women and 1,926 men married in the colony before 1740, we show that women bearing their last child late in life had longer postreproductive lives, suggesting that late menopause is associated with an overall slower rate of aging. Increased parity had an opposite, detrimental effect on women's postreproductive survival. On the other hand, husbands' longevity was less sensitive to parity and reproductive history. For husbands, increased effective family size (EFS), i.e., the number of children who survived up to age 18 in a "compressed" reproductive time span meant higher chances for survival past age 60. Children may serve as valuable economic assets on farmsteads during colonization, which would mostly benefit fathers. In a collaborative effort to unveil postreproductive aging patterns in historical populations, the results are compared to previous analyses conducted on the Utah Population Database and evolutionary and sociodemographic theories are addressed in light of these results. [ABSTRACT FROM AUTHOR]

Remarkably few studies have been conducted into the prevalence and possible influence of close kin marriage on fertility and mortality in northern European populations. The Demographic DataBase at Umeå University offers a unique opportunity to correct this situation, with data on births, deaths, and marriages in the Skellefteå region of Sweden for the period 1720-1899 collected by the State Lutheran Church. The data are made more interesting by the fact that until 1680 first cousin unions were prohibited in Sweden; and from 1680 until 1844 a royal dispensation was needed before such unions could proceed. Of the 14,639 marriages initially studied, 20.8 percent were between couples related as sixth cousins or closer, with a significant increase in first cousin marriages post-1844. Using logistic regression, two subsets of marriages contracted from 1780 to 1899 were investigated with respect to fertility and mortality. First cousin marriages were strongly favored by freeholders and peasant landowning families; and in some families they had been preferentially contracted across successive generations. Consanguinity appeared to exert no influence on fertility. However, first cousin couples had higher rates of stillbirths and more deaths in infancy and early childhood among their progeny. This excess mortality was probably associated with the expression of detrimental recessive genes, although nongenetic factors may also have been involved. There was evidence of the clustering of multiple deaths within first cousin families, which likewise would be consistent with a genetic aetiology. Overall, the data confirm the significance of close consanguinity as an important demographic variable in this European population. [ABSTRACT FROM AUTHOR]

This essay explores the role played by inheritance on human longevity. We estimate a model of overall mortality among married persons aged 50 years and above taking genetic as well as socioeconomic and environmental factors into account. We consider whether these factors have temporary or long-lasting effects on health. The demographic and economic individual level data come from the Scanian Demographic Database. These data cover five rural parishes in the southernmost part of Sweden for the period 1813-1894. To these, local grain prices, as an indicator of food costs, and the local infant mortality rate, as an indicator of the disease load, have been added. We find that age of death of the mother and the father have persistent impacts on their adult children's overall mortality regardless of sex, even after controlling for socioeconomic and environmental factors throughout the life course. In addition, we find strong birth cohort effects and effects of the disease load in the first year of life on male offspring. We are, however, unable to find any effects of socioeconomic status, neither at the time of birth or achieved later in life, a result consistent with earlier findings. [ABSTRACT FROM AUTHOR]

Previous studies have shown that the family influences migration decisions in various ways, but very few of them take into account past migrations among the kinship group. In this study, we take advantage of new historical data, based on the TRA survey, to discuss the extent to which kinship influences migration. We use the concept of spatial capital to capture all the knowledge families possess about geographical locations. We are then able to show how this knowledge is—or is not—handed down from one generation to another. This is a key point of the analysis of migration as it means that migration decisions are not only influenced by individual characteristics or economic or historical context, but also by the past migration behavior of the family. As such, migration is not only an investment for the migrant or for his close relatives but can be seen as a long-term investment of the kinship group. [ABSTRACT FROM AUTHOR]

The present study aims to investigate the parity specific effect of kin help on the transition between births among natural and controlled fertility birth cohorts of the Bejsce parish. The hypothesis states that kin help should be of particular importance in the case of higher order births. Thus, kin effects understood as reduction in the costs of childbearing (direct childcare, provision of the resources) or nutritional effects should be of particular importance at higher parities. The analyses are based on the multilevel hazard models of parity transition with kin effects represented by time-constant and time-varying covariates. The data used for the estimation of the models come from the reconstitution of the registers from Bejsce parish located in south-central Poland. The reconstitution covers the period between 1730 and 1968. The results suggest that there was a strong kin effect especially at higher parities. These effects were mostly associated with the presence of nongenerative relatives (grandparents). The analyses reveal only weak differences in the kin effect between natural and controlled fertility regimes. [ABSTRACT FROM AUTHOR]

This study focuses on the effects on survival of children of growing up in a family with or without both biological parents and/or stepparents. We use data from a representative sample of births from cohorts born in the Netherlands between 1850 and 1922. We first describe the long-term trends in the presence of fathers, mothers, and stepparents in families of children between birth and age 15. We then study the impact on survival of children of (a) the permanent absence of one of the parents, and (b) the entrance of a stepparent, focusing on changes in the effect over time and social class. Our analysis confirmed the more important role of the mother for survival, and showed that more durable effects of parental absence grew in importance over time, and revealed hardly any observed social class differences on mortality effects. [ABSTRACT FROM AUTHOR]

We make use of a uniquely detailed and voluminous longitudinal, individual and household-level dataset from rural Liaoning in northeast China during the eighteenth and nineteenth centuries to compare the role of communities, kin networks, and households in determining individual social and demographic outcomes in late imperial China. We assess the importance of each level of social organization by examining how individual chances of attainment, fertility, marriage, and mortality were correlated with rates at the level of the household, the household group, the descent group, and the village. We then examine relations across outcomes by measuring how individual chances for each outcome were associated with rates for other outcomes at each of the four levels of social organization. Results indicate that each level of organization was important in the sense that clustering was apparent, though the precise pattern of associations varied by outcome. Finally, motivated by recent results for contemporary China that suggest that villages dominated by single kin groups or small numbers of kin groups have better provision of public goods (Tsai 2004), we carry out a preliminary assessment of the importance of "collective efficacy" in late imperial Liaoning villages by examining whether residents of villages that were more homogeneous in terms of their descent group composition had better provision of public goods, as reflected in more favorable demographic outcomes. [ABSTRACT FROM AUTHOR]

This chapter addresses the role of health-related characteristics as a basis of marriage partner selection in a preindustrial population with a low level of social differentiation and a high level of mortality. We measured health characteristics by the level of infant and child mortality in the family of origin of the marriage partners. We observed a homogamous marriage pattern according to mortality in the family of origin. We argue that mortality in the family of origin was probably used to evaluate potential marriage partners. The level of infant and child mortality in a family can be seen as an indicator of health status, (future) social position, physical appearance, or reputation of the potential partner and his family. [ABSTRACT FROM AUTHOR]

This chapter deals with the role and influence of kinship on the decision to marry in a rural population of mid nineteenth century Italy. The reason for this choice lies in the particular social structure of that community, where the two most important social groups, sharecroppers and day laborers, had almost antithetic marriage patterns and family formation systems. Our study demonstrates the key role of kin, especially coresident ones, in modifying the risk of marriage. This situation was particularly pronounced within the large and complex sharecropping households. Constrained by the absolute necessity to maintain not only a balance between farm size and household size but also an adequate supply of labor within the household, sharecroppers posed limits and restrictions on marriages of members, especially men. Gender, age, and marital status were chief factors determining who could marry and when. On the other hand, day laborers were less sensitive to household structure as their activity depended neither on the household labor force nor on the characteristics of the farm. In this case, the access to marriage, ruled only by birth order, was less controlled for both men and women. As for the role of kin outside the household, difficulties in the reconstruction of the entire kin network made the results less conclusive. However, it was only effective in modifying the risk of marriage for women living in sharecropping households. Large and deep-rooted networks of relations favored a woman's access to marriage, especially when a local man was involved, suggesting the use of marriage to establish and reinforce local family alliances. [ABSTRACT FROM AUTHOR]

The historical demographic study of family structure and kinship has experienced tremendous change over the last 20 years. While the focus in the past has been on the family and the household, including coresident kin, considerable resources have recently been devoted to delineating nonresident kin. This has been done not only in societies where kinship was a major organizing principle by which social groups maintained the security and well-being of their members, but also in Western societies, where the state played part of this role. The reason for the interest in family and kin networks also in Western societies is due to the fact that, while the state had the ultimate responsibility for the security and well-being of its citizens, this task was often devolved to families and employers, the state stepping in only if these agents failed. Thus, for most of the time, and for the majority of the population, the family and the household, and sometimes also the nonresident kin, were instrumental in securing living standards for their members in both the West and the East. [ABSTRACT FROM AUTHOR]