A death in the family: household structure and mortality in rural Liaoning: life-event and time-series analysis, 1792-1867

Does the sex ratio at sexual maturity affect men's later-life mortality risks? Evidence from historical China

This study examines the relationship between the male-to-female sex ratio (measured as the proportion male) at sexual maturity and later-life mortality risks in the context of pre-industrial northeast China, using registration data from the Qing Dynasty. We find that a higher male-to-female sex ratio at sexual maturity is associated with a higher later-life mortality risk among men. This association is likely due to the long-term adverse consequences of stress caused by low mate availability at sexual maturity. We further find that a high sex ratio at sexual maturity mitigates the health benefits of marriage and exacerbates the health disadvantages of holding an official position in Qing China.

Males' Later-Life Mortality Consequences of Coresidence With Paternal Grandparents: Evidence From Northeast China, 1789-1909

In this study, we investigate the effect of early-life coresidence with paternal grandparents on male mortality risks in adulthood and older age in northeast China from 1789 to 1909. Despite growing interest in the influence of grandparents on child outcomes, few studies have examined the effect of coresidence with grandparents in early life on mortality in later life. We find that coresidence with paternal grandmothers in childhood is associated with higher mortality risks for males in adulthood. This may reflect the long-term effects of conflicts between mothers and their mothers-in-law. These results suggest that in extended families, patterns of coresidence in childhood may have long-term consequences for mortality, above and beyond the effects of common environmental and genetic factors, even when effects on childhood mortality are not readily apparent.

Kin and birth order effects on male child mortality: three East Asian populations, 1716-1945

Human child survival depends on adult investment, typically from parents. However, in spite of recent research advances on kin influence and birth order effects on human infant and child mortality, studies that directly examine the interaction of kin context and birth order on sibling differences in child mortality are still rare. Our study supplements this literature with new findings from large-scale individual-level panel data for three East Asian historical populations from northeast China (1789-1909), northeast Japan (1716-1870), and north Taiwan (1906-1945), where preference for sons and first-borns is common. We examine and compare male child mortality risks by presence/absence of co-resident parents, grandparents, and other kin, as well as their interaction effects with birth order. We apply discrete-time event-history analysis on over 172,000 observations of 69,125 boys aged 1-9 years old. We find that in all three populations, while the presence of parents is important for child survival, it is more beneficial to first/early-borns than to later-borns. Effects of other co-resident kin are however null or inconsistent between populations. Our findings underscore the importance of birth order in understanding how differential parental investment may produce child survival differentials between siblings.

Do grandparents compete with or support their grandchildren? In Guatemala, paternal grandmothers may compete, and maternal grandmothers may cooperate

Previous research has found that the presence of grandparents, particularly grandmothers, is often positively associated with child survival. Little research has explored the potential mechanisms driving these associations. We use data from rural Guatemala to test whether contact with and direct investment (advice and financial) from grandparents is associated with child health, proxied by height. Our results demonstrate the complexity of family relationships and their influence on child health, suggesting that both cooperative and competitive relationships exist within the family. The clearest evidence we find for grandparental influence is that having a living paternal grandmother tends to be negatively associated with child height. By contrast, contact with maternal kin appears broadly to be beneficial for child height, although these relationships are weaker. These patterns are mirrored in maternal body mass index, suggesting grandparental influence acts partly through maternal health. These findings support the hypotheses that, under conditions of limited resources, family relationships may be competitive within the family lineage which shares the same resource base, but cooperative when there are few costs to cooperation. Finally, financial assistance from maternal grandfathers is positively correlated with infant length but negatively with the height of older children, perhaps because the receipt of financial support is an indication of need. The provision of advice shows no associations with child height.

Kin and Child Survival in Rural Malawi : Are Matrilineal Kin Always Beneficial in a Matrilineal Society?

This paper investigates the impact of kin on child survival in a matrilineal society in Malawi. Women usually live in close proximity to their matrilineal kin in this agricultural community, allowing opportunities for helping behavior between matrilineal relatives. However, there is little evidence that matrilineal kin are beneficial to children. On the contrary, child mortality rates appear to be higher in the presence of maternal grandmothers and maternal aunts. These effects are modified by the sex of child and resource ownership: female children and children in households where women, rather than men, own land suffer higher mortality rates in the presence of maternal kin. These modifiers suggest the detrimental effects of matrilineal kin may result from competition between such kin for resources. There are some positive effects of kin on child survival: the presence of elder siblings of both sexes is correlated with higher survival rates, and there is some weak evidence that paternal grandmothers may be beneficial to a child's survival chances. There is little evidence that any male kin, whether matrilineal or patrilineal, and including fathers, affect child mortality rates. This study highlights the importance of taking social and ecological context into account when investigating relationships between kin.

Household demography and early childhood mortality in a rice-farming village in Northern Laos

This paper extends Alexandr Chayanov's model of changing household demography (specifically the ratio of food consumers to food producers) and its influence on agricultural behavior so that it includes possible adverse effects of a rising ratio on nutritional status and early childhood mortality within the household. We apply the model to 35 years' worth of longitudinal demographic and economic data collected in the irrigated-rice growing village of Na Savang in northern Laos. When appropriate controls are included for other household variables, unobserved inter-household heterogeneity, and changes in local conditions and national policy over the study period, the analysis suggests that a unit increase in the household's consumer/producer ratio induces something like a nine-fold increase in the risk of death among household members aged less than five years. Monte Carlo simulation studies suggest that this may be an over-estimate but also that the effect is probably real and likely to be an important factor in household demography. At the very least, the results suggest that Chayanov's model still has theoretical relevance and deserves to be revived.

Kinship matters: long-term mortality consequences of childhood migration, historical evidence from northeast China, 1792-1909*

Unlike previous migration studies which mainly focus on individual migration, this article examines the long-term mortality consequences of childhood migration and resettlement. Using a unique Chinese historical population database, we trace 30,517 males from childhood onwards between 1792 and 1909, 542 of whom experienced childhood migration. We apply discrete-time event-history analysis and include a fixed effect of common grandfather to account for unobservable characteristics of the extended family. We also explore the influence of social networks on early-life migration experience by including kin network at destination. Our findings suggest that migration in childhood has substantial long-term effects on survivorship in later ages. From age 16 sui to 45 sui, kin network at destination mediates the negative effects of childhood migration and lowers mortality risks. Moreover, child migrants who survive to older ages subsequently experience lower mortality. Such findings contribute to a better understanding of the implications of social behavior and social context for human health.

Living Arrangements and the Elderly: An Analysis of Old-Age Mortality by Household Structure in Casalguidi, 1819–1859

The elevated levels of protection, assistance, and care enjoyed by the elderly living in complex households has long been a key assumption of many family system theories. However, although this hypothesis has been demonstrated for contemporary contexts, quantitative evidence for past populations is particularly scarce, if not nonexistent. This article investigates the relationship between old-age mortality and living arrangements in a mid–nineteenth century Tuscan population, where the joint family system of sharecroppers coexisted alongside the nuclear system of day laborers. Our findings demonstrate that within complex households, the complexity of relationships, gender inequalities, and possible competition for care and resources among the most vulnerable household members—namely, the elderly and the young—weakens the assumption that the elderly benefitted from lower rates of old-age mortality.

Are stepparents always evil? Parental death, remarriage, and child survival in demographically saturated Krummhörn (1720-1859) and expanding Québec (1670-1750)

Parental death precipitates a cascade of events leading to more or less detrimental exposures, from the sudden and dramatic interruption of parental care to cohabitation with stepparents and siblings in a recomposed family. This article compares the effect of early parental loss on child survival in the past in the Krummhörn region of East Frisia (Germany) and among the French Canadian settlers of the Saint Lawrence Valley (Québec, Canada). The Krummhörn region was characterized by a saturated habitat, while the opportunities for establishing a new family were virtually unlimited for the French Canadian settlers. Early parental loss had quite different consequences in these dissimilar environments. Event history analyses with time-varying specification of family structure are used on a sample of 7,077 boys and 6,906 girls born between 1720 and 1859 in the Krummhörn region and 31,490 boys and 33,109 girls whose parents married between 1670 and 1750 in Québec. Results indicate that in both populations, parental loss is associated with increased infant and child mortality. Maternal loss has a universal and consistent effect for both sexes, while the impact of paternal loss is less easy to establish and interpret. On the other hand, the effect of the remarriage of the surviving spouse is population-specific: the mother's remarriage has no effect in Krummhörn, while it is beneficial in Québec. In contrast, the father's remarriage in Krummhörn dramatically reduces the survival chances of the children born from his former marriage, while such an effect is not seen for Québec. These population-specific effects appear to be driven by the availability of resources and call into question the universality of the "Cinderella" effect.

Alternatives to the grandmother hypothesis: a meta-analysis of the association between grandparental and grandchild survival in patrilineal populations

We conducted a meta-analysis of 17 studies that tested for an association between grandparental survival and grandchild survival in patrilineal populations. Using two different methodologies, we found that the survival of the maternal grandmother and grandfather, but not the paternal grandmother and grandfather, was associated with decreased grandoffspring mortality. These results are consistent with the findings of psychological studies in developed countries (Coall and Hertwig Behavioral and Brain Sciences 33:1-59, 2010). When tested against the predictions of five hypotheses (confidence of paternity; grandmothering, kin proximity, grandparental senescence, and local resource competition), our meta-analysis results are most in line with the local resource competition hypothesis. In patrilineal and predominantly patrilocal societies, the grandparents who are most likely to live with the grandchildren have a less beneficial association than those who do not. We consider the extent to which these results may be influenced by the methodological limitations of the source studies, including the use of retrospective designs and inadequate controls for confounding variables such as wealth.

Widowhood and mortality: a meta-analysis and meta-regression

The study of spousal bereavement and mortality has long been a major topic of interest for social scientists, but much remains unknown with respect to important moderating factors, such as age, follow-up duration, and geographic region. The present study examines these factors using meta-analysis. Keyword searches were conducted in multiple electronic databases, supplemented by extensive iterative hand searches. We extracted 1,377 mortality risk estimates from 123 publications, providing data on more than 500 million persons. Compared with married people, widowers had a mean hazard ratio (HR) of 1.23 (95% confidence interval (CI), 1.19-1.28) among HRs adjusted for age and additional covariates and a high subjective quality score. The mean HR was higher for men (HR, 1.27; 95% CI, 1.19-1.35) than for women (HR, 1.15; 95% CI, 1.08-1.22). A significant interaction effect was found between gender and mean age, with HRs decreasing more rapidly for men than for women as age increased. Other significant predictors of HR magnitude included sample size, geographic region, level of statistical adjustment, and study quality.

Household-level predictors of the presence of servants in Northern Orkney, Scotland, 1851-1901

Servants were an important part of the northwestern European household economy in the preindustrial past. This study examines household-level characteristics that are predictive of the presence of rural servants using data from Orkney, Scotland. The number of servants present in a household is related to household composition, landholding size, and the marital status of the household head. In addition, the sex of the particular servant hired reveals that the labor of male and female servants is not fungible. The sex of the servant hired is related to the ratio of male and female household members of working age, the occupation of the head, household composition, and the size of the household's landholding.

Fertility control in historical China revisited: New Methods for an Old Debate

We revisit the debate over deliberate control of reproduction in historical China through a reanalysis of data from the Qing (1644-911) Imperial Lineage that accounts for physiological or other differences between couples that affected their chances of having children. Even though studies of contemporary and historical European fertility suggest that failing to control for such differences may obscure evidence of parity-specific control, previous studies of historical Chinese fertility have not accounted for them. We show that in the Lineage, failure to account for such differences leads the association between number of children already born and the chances of having another birth to appear to be positive, but that once they are accounted for properly, the relationship is inverted. Based on this, we conclude that lineage members adjusted their reproductive behavior based on the number of children. We also show that the sex composition and survival of previous births affected reproductive behavior. We conclude by suggesting that one way forward in the ongoing debate over fertility control in historical China is through application of such methods to other datasets and comparison of results. We also suggest that progress in the debate over fertility in historical China has been impeded by confusion over the definition of fertility control, so that some behaviors are recognized as fertility control by some parties in the debate but not others.

Are humans cooperative breeders?: Most studies of natural fertility populations do not support the grandmother hypothesis

In discussing the effects of grandparents on child survival in natural fertility populations, Coall & Hertwig (C&H) rely extensively on the review by Sear and Mace (2008). We conducted a more detailed summary of the same literature and found that the evidence in favor of beneficial associations between grandparenting and child survival is generally weak or absent. The present state of the data on human alloparenting supports a more restricted use of the term “cooperative breeding.” Human stem family situations with celibate helpers-at-the-nest can be described as cooperatively breeding, but the term is a poor fit to many human family systems.

Parental effects on offspring longevity—evidence from 17th to 19th century reproductive histories

BACKGROUND

Family studies provide support for a modest genetic influence on offspring life span, although the magnitude of these correlations is small.

AIM

The study aimed to clarify the relative contributions of parental age at birth and overall parental longevity on offspring lifespan, and to identify the biological and cultural mechanisms.

SUBJECTS AND METHODS

Information was derived from two village genealogies (1650-1927) encompassing 9979 births (5315 males, 4664 females). Data selection was guided by the inclusion of information about parental age at birth and lifespan, offspring lifespan and cohort-specific life expectancy.

RESULTS

Parental age at reproduction displayed a negative association with offspring survivability, which was caused by a host of biological as well as environmental factors. In contrast, parental lifespan was positively associated with offspring age at death. These effects differed by parent's and child's sex.

CONCLUSION

The maternal age effect on female progeny is thought to be indicative of a preferential genetic load. From an evolutionary point of view, direct selection for maternal lifespan may be an adaptive strategy to enhance child survival prospects.

Long-term mortality consequences of childhood family context in Liaoning, China, 1749-1909

We examine the effects on adult and old age mortality of childhood living arrangements and other aspects of family context in early life. We focus on features of family context that have already been shown to be associated with infant or child mortality in historical and developing country populations. We apply discrete-time event-history analysis to longitudinal, individual-level household register data for a rural population in northeast China from the eighteenth and nineteenth centuries. Loss of a mother in childhood, a short preceding birth interval, and high maternal age were all associated with elevated mortality risks later in life. Such effects persist in a model with fixed effects that account for unobserved characteristics of the community and household. An important implication of these results is that in high-mortality populations, features of early-life family context that are associated with elevated infant and child mortality may also predict adverse mortality outcomes in adulthood.