Families in comparison: An individual-level comparison of life-course and family reconstructions between population and vital event registers.

It remains unknown how different types of sources affect the reconstruction of life courses and families in large-scale databases increasingly common in demographic research. Here, we compare family and life-course reconstructions for 495 individuals simultaneously present in two well-known Dutch data sets: LINKS, based on the Zeeland province's full-population vital event registration data (passive registration), and the Historical Sample of the Netherlands (HSN), based on a national sample of birth certificates, with follow-up of individuals in population registers (active registration). We compare indicators of fertility, marriage, mortality, and occupational status, and conclude that reconstructions in the HSN and LINKS reflect each other well: LINKS provides more complete information on siblings and parents, whereas the HSN provides more complete life-course information. We conclude that life-course and family reconstructions based on linked passive registration of individuals constitute a reliable alternative to reconstructions based on active registration, if case selection is carefully considered.

The family name as socio-cultural feature and genetic metaphor: from concepts to methods.

A recent workshop entitled "The Family Name as Socio-Cultural Feature and Genetic Metaphor: From Concepts to Methods" was held in Paris in December 2010, sponsored by the French National Centre for Scientific Research (CNRS) and by the journal Human Biology. This workshop was intended to foster a debate on questions related to the family names and to compare different multidisciplinary approaches involving geneticists, historians, geographers, sociologists and social anthropologists. This collective paper presents a collection of selected communications.

Longevity Relatives Count score identifies heritable longevity carriers and suggests case improvement in genetic studies.

Loci associated with longevity are likely to harbor genes coding for key players of molecular pathways involved in a lifelong decreased mortality and decreased/compressed morbidity. However, identifying such loci is challenging. One of the most plausible reasons is the uncertainty in defining long-lived cases with the heritable longevity trait among long-living phenocopies. To avoid phenocopies, family selection scores have been constructed, but these have not yet been adopted as state of the art in longevity research. Here, we aim to identify individuals with the heritable longevity trait by using current insights and a novel family score based on these insights. We use a unique dataset connecting living study participants to their deceased ancestors covering 37,825 persons from 1,326 five-generational families, living between 1788 and 2019. Our main finding suggests that longevity is transmitted for at least two subsequent generations only when at least 20% of all relatives are long-lived. This proves the importance of family data to avoid phenocopies in genetic studies.

Relatives as spouses: preferences and opportunities for kin marriage in a Western society.

This article investigates the determinants of kin marriage on the basis of a large-scale database covering a major rural part of The Netherlands during the period 1840-1922. We studied three types of kin marriage: first cousin marriage, deceased spouse's sibling marriage, and sibling set exchange marriage. Almost 2% of all marriages were between first cousins, 0.85% concerned the sibling of a former spouse, while 4.14% were sibling set exchange marriages. While the first two types generally declined across the study period, sibling set exchange marriage reached a high point of almost 5% between 1890 and 1900. We found evidence for three mechanisms explaining the choice for relatives as spouses, centering both on preferences and on opportunities for kin marriage. Among the higher and middle strata and among farmers, kin marriages were commonly practiced and played an important role in the process of social class formation in the late nineteenth century. An increased choice for cousin marriage as a means of enculturation was observed among orthodox Protestants in the Bible Belt area of The Netherlands. Finally, all studied types of kin marriage took place more often in the relatively isolated, inland provinces of The Netherlands. Sibling set exchange marriages were a consequence of the enlarged supply of same-generation kin as a result of the demographic transition.

Longevity defined as top 10% survivors and beyond is transmitted as a quantitative genetic trait.

Survival to extreme ages clusters within families. However, identifying genetic loci conferring longevity and low morbidity in such longevous families is challenging. There is debate concerning the survival percentile that best isolates the genetic component in longevity. Here, we use three-generational mortality data from two large datasets, UPDB (US) and LINKS (Netherlands). We study 20,360 unselected families containing index persons, their parents, siblings, spouses, and children, comprising 314,819 individuals. Our analyses provide strong evidence that longevity is transmitted as a quantitative genetic trait among survivors up to the top 10% of their birth cohort. We subsequently show a survival advantage, mounting to 31%, for individuals with top 10% surviving first and second-degree relatives in both databases and across generations, even in the presence of non-longevous parents. To guide future genetic studies, we suggest to base case selection on top 10% survivors of their birth cohort with equally long-lived family members.

Marriage Timing over the Generations.

Strong relationships have been hypothesized between the timing of marriage and the familial environment of the couple. Sociologists have identified various mechanisms via which the age at marriage in the parental generation might be related to the age at marriage of the children. In our paper we study this relationship for historical populations. We use a dataset consisting of several hundreds of thousands of marriages contracted in three of the 11 Dutch provinces between 1812 and 1922. We identified the generational links between the brides, grooms, their parents, and grandparents. We studied (a) whether there is a relationship between ages at marriage of (grandfathers) fathers and sons, and ages at marriage of (grandmothers) mothers and daughters and (b) whether this relationship might be explained by social class. We find evidence for a clear effect of the family on age at marriage and substantial intergenerational transmission. The impact that the family of origin has on age at entry into marriage can partly be attributed to social class. We also observed positive effects of grandparents' age at marriage on their offspring's age at marriage.

The Intermediate Data Structure (IDS) for Longitudinal Historical Microdata, version 4.

The Intermediate Data Structure (IDS) is a standard data format that has been adopted by several large longitudinal databases on historical populations. Since the publication of the first version in Historical Social Research in 2009, two improved and extended versions have been published in the Collaboratory Historical Life Courses. In this publication we present version 4 which is the latest 'official' standard of the IDS. Discussions with users over the last four years resulted in important changes, like the inclusion of a new table defining the hierarchical relationships among 'contexts,' decision schemes for recording relationships, additional fields in the metadata table, rules for handling stillbirths, a reciprocal model for relationships, guidance for linking IDS data with geospatial information, and the introduction of an extended IDS for computed variables.

Historical trends in the correlation of sibling deaths in infancy in the Netherlands.

In this article, we study temporal, regional, and social variation in infant and childhood death clustering in The Netherlands, using data from three provinces. The data relate to children born in 90,000 marriages contracted between the beginning and the last quarter of the nineteenth century. Descriptive indicators show that death clustering was more frequent in the province of Zeeland and more common in the lower classes, and that it increased in two provinces over time. Shared frailty hazard models make it clear that the number of children who died before the birth of an index child had a negative effect on the mortality of index children, whereas earlier stillbirths and the number of children who died when the index child was at a young age had an increasing effect on the mortality of index children.