Bertrand Desjardins

Is there a trade-off between fertility and longevity? A comparative study of women from three large historical databases accounting for mortality selection.

Frontier populations provide exceptional opportunities to test the hypothesis of a trade‐off between fertility and longevity. In such populations, mechanisms favoring reproduction usually find fertile ground, and if these mechanisms reduce longevity, demographers should observe higher postreproductive mortality among highly fertile women. We test this hypothesis using complete female reproductive histories from three large demographic databases: the Registre de la population du Québec ancien (Université de Montréal), which covers the first centuries of settlement in Quebec; the BALSAC database (Université du Québec à Chicoutimi), including comprehensive records for the Saguenay‐Lac‐St‐Jean (SLSJ) in Quebec in the nineteenth and twentieth centuries; and the Utah Population Database (University of Utah), including all individuals who experienced a vital event on the Mormon Trail and their descendants. Together, the three samples allow for comparisons over time and space, and represent one of the largest set of natural fertility cohorts used to simultaneously assess reproduction and longevity. Using survival analyses, we found a negative influence of parity and a positive influence of age at last child on postreproductive survival in the three populations, as well as a significant interaction between these two variables. The effect sizes of all these parameters were remarkably similar in the three samples. However, we found little evidence that early fertility affects postreproductive survival. The use of Heckmans procedure assessing the impact of mortality selection during reproductive ages did not appreciably alter these results. We conclude our empirical investigation by discussing the advantages of comparative approaches. Am. J. Hum. Biol., 2009.

Effects of Reproductive Behaviour on Infant Mortality of French-Canadians During the Seventeenth and Eighteenth Centuries

In this paper the effects of mothers age, birth order, sibship size breastfeeding habits of the mother and length of previous birth interval on infant mortality among the French-Canadian population during the seventeenth and eighteenth centuries are considered. A U-shaped effect of mothers age and a J-shaped effect of birth order are observed. The relation with birth order is shown to hold, even after controlling for sibship size. Study of the effect of sibship size leads to a relation between the fates of siblings and definition of a familial component in infant mortality. A significant factor in that familial component is the breastfeeding habit of the mother. Finally, the effect of the length of the previous birth interval is scrutinized, but no single explanation is found that fully accounts for the observed inverse relation with infant mortality.

Mother's death and child survival: the case of early Quebec.

The aim of this paper is to account for the effect of mothers death on child survival in a historical population. Using comprehensive data on the early French Canadian population of Quebec, evidence is provided for a higher risk of dying for motherless children that remains significant over all childhood and long after the death of the mother. The specific effect of the loss of maternal care was estimated by comparing mortality before and after mothers death, furnishing a means to control for family heterogeneity. No differential in investment between genders was detected before age 3, but older girls suffered a three-fold higher susceptibility to mothers death than their male counterparts. This suggests that grown-up girls assuming the responsibilities of the missing mother had a lower chance of survival.

Familial Aggregation of Survival and Late Female Reproduction

Women giving birth at advanced reproductive ages in natural fertility conditions have been shown to have superior postmenopausal longevity. It is unknown whether improved survival is more likely among relatives of late-fertile women. This study compares survival past age 50 of men with and without a late-fertile sister in two populations: Utahns born in 1800-1869 identified from the Utah Population Database and Québec residents born in 1670-1750 identified from the Programme de recherche en démographie historique. Male survival was greater for those with, rather than without, a sister reproducing after age 45, particularly among men with at least three sisters (Utah rate ratio [RR] = .801, 95% CI = 0.687-0.940; Quebec RR = .786, 95% CI = 0.664-0.931). Survival of wives was unaffected by whether their husbands had a late-fertile sister, suggesting a weak influence of unmeasured socioenvironmental factors. These results support the hypothesis that late female fertility and slow somatic aging may be promoted by the same genetic variants.

The Family Name as Socio-Cultural Feature and Genetic Metaphor: From Concepts to Methods

Abstract 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.

Dealing with Problems in Data Quality for the Measurement of Mortality at Advanced Ages in Canada

Abstract The level and age trajectory of mortality at advanced ages in Canada are not readily and exactly obtained, because of problems with the reliability of data on deaths and on population counts beyond a certain point in the official statistics. There are two ways to ensure nonetheless the termination of the life tables. One consists of finding ways to validate a sufficient number of unbiased high ages at death to produce an accurate measure with the extinct, or almost extinct, generation method. This paper presents the results of a systematic verification of ages at death and a preliminary estimation of centenarian mortality based on observations, which seems to lend credence to a leveling off of mortality rates at the highest ages for females. Another is to establish convincing evidence as to the pattern of survival at the very highest ages; mathematical techniques can then be used to generate the rates as an extension of mortality at ages 70 to 90 or 100. Historical data were used here to give an insight on what this pattern of survival could be. Contrary to what might have been expected, the progression of mortality remains pretty much exponential until the unavoidable erratic values corresponding to the few extreme observations are reached. This entails that whatever the nature of the selections that would produce a slowing down of the rate of increase of the rates at the highest ages, they did not express themselves conclusively a few centuries ago.

Typologies of Extreme Longevity Myths

Purpose. Political, national, religious, and other motivations have led the media and even scientists to errantly accept extreme longevity claims prima facie. We describe various causes of false claims of extraordinary longevity. Design and Methods. American Social Security Death Index files for the period 1980–2009 were queried for individuals with birth and death dates yielding ages 110+ years of age. Frequency was compared to a list of age-validated supercentenarians maintained by the Gerontology Research Group who died during the same time period. Age claims of 110+ years and the age validation experiences of the authors facilitated a list of typologies of false age claims. Results. Invalid age claim rates increase with age from 65% at age 110-111 to 98% by age 115 to 100% for 120+ years. Eleven typologies of false claims were: Religious Authority Myth, Village Elder Myth, Fountain of Youth Myth (substance), Shangri-La Myth (geographic), Nationalist Pride, Spiritual Practice, Familial Longevity, Individual and/or Family Notoriety, Military Service, Administrative Entry Error, and Pension-Social Entitlement Fraud. Conclusions. Understanding various causes of false extreme age claims is important for placing current, past, and future extreme longevity claims in context and for providing a necessary level of skepticism.

L'héritabilité de la longévité.

Desjardins Bertrand et Charbonneau Hubert. - Herencia de la longevidad. ^La longevidad de los hijos, sera el reflejo de la de sus padres? Nosotros, la verifica- mos en la poblacion de Quebec de los siglos XVII y XVIII, para los immigrantes casados antes de 1665 y para su descendencia. Mientras mas viejos mueren los hijos, se observa que sus pares murieron tambien, en termine» medio, a una edad avanzada. La asociacion es mo- desta y a veces no signilcantiva, pero siempre en el sentido previsto, en particular рог los hijos varones y sus padres. Ademas, al deceso de Ios hermanos y hermanas, sus edades se encuentran menos dispersas, que aquellas de los que no son ni hermanos ni hermanas, esto confirma la hipotesis de una composante familiar de longevidad. Esta resalta aun mas, cuando no hay ninguna relacion entre las edades al deceso del conyugue, ligados рог el ma- trimonio, y no por la sangre.

Intervals between marriage and first birth in mothers and daughters

Marriage-first birth intervals are examined in two historical populations, Quebec (1608-1765) and Haut-Jura (1689-1980), comparing intervals in mothers and daughters, and in sister-sister pairs. The results point to a weak relationship between intervals of mothers and daughters, though it does not attain significance. Shared environment does not seem to be responsible since there is no association between pairs of sisters from the same populations.

Demographic Aspects of the 1702-1703 Smallpox Epidemic in the St. Lawrence Valley

Data compiled by the Programme de recherche en demographie historique of the Universite de Montreal were used to number and characterize deaths within the population of European extraction from the 1702-1703 smallpox epidemic in the St-Lawrence valley. Between 6% and 6.5% of the settled population in the late fall of 1702 was eliminated by the disease; adding the death of an extra 25% of newborns the epidemics toll reached some 1300. A significant proportion of adults died among the Canadian-born population surpassing 10% for women of childbearing ages in particular. This proves that contrary to what most observers have written smallpox was not prevalent among the non-native population during the XVIIth century. (SUMMARY IN FRE) (EXCERPT)