"Previous research has demonstrated that consanguineous marriage is a vector for socioeconomic inheritance and for the maintenance of family structure and property. On the basis of reconstituted families from the Krummhörn, Ostfriesland in the 18th and 19th centuries, we examine statistical correlations between ascertained inbreeding coefficients (F) based on family trees and socioeconomic status as well as the intergenerational transmission of landholdings. Semiparametric copula/bivariate regression models with non-random sample selection were applied to estimate F and the proportion of medium (0.0625>F≥0.0156) or high consanguineous unions (F≥0.0625), respectively. Our estimates for F as well as for the proportion of medium (0.0625>F≥0.0156) or high consanguineous unions (F≥0.0625) are significantly higher among socioeconomically privileged large farmer families than among the landless portion of the population. At the same time, our analyses show that a high level of consanguinity is associated with an increased intergenerational transmission of landholdings through the patriline (but not the matriline). We discuss the reproductive consequences of consanguinity among large farmers in connection with local resource competition, intensive kinship, and potential in-law conflicts." (Abstract)
Evolution and human behavior Amsterdam [u.a.] : Elsevier Science, 1997 40(2019), 2, Seite 204-213 Online-Ressource
Motivated by the cooperative breeding hypothesis, we investigate the effect of having kin on the mortality of reproductive women based on family reconstitutions for the Krummhörn region (East Frisia, Germany, 1720–1874). We rely on a combination of Cox clustered hazard models and hazard models stratified at the family level. In order to study behavior-related effects, we run a series of models in which only kin who lived in the same parish are considered. To investigate structural, non-behavior-related effects, we run a different model series that include all living kin, regardless their spatial proximity. We find that women of reproductive age who had a living mother had a reduced mortality risk. It appears that having living sisters had an ambivalent impact on women’s mortality: i.e., depending on the socioeconomic status of the family, the effect of having living sisters ranged between representing a source of competition and representing a source of support. Models which are clustered at the family level suggest that the presence of a living mother-in-law was associated with reduced mortality among her daughters-in-law especially among larger-scale farm families. We interpret this finding as a consequence of augmented consanguineous marriages among individuals of higher social strata. For instance, in first cousin marriages, the mother-in-law could also be a biological aunt. Thus, it appears that among the wealthy elite, the genetic in-law conflict was neutralized to some extent by family solidarity. This result further suggests that the tipping point of the female trade-off between staying with the natal family and leaving the natal family to join an economically well-established in-law family might have been reached very quickly among women living under the socioeconomic conditions of the Krummhörn region.
PLOS ONE San Francisco, California, US : PLOS, 2006 Bd. 13.2018, 3, Art.-Nr. e0193252, insges. 12 S. Online-Ressource
von Cody T. Ross ; Monique Borgerhoff Mulder ; Seung-Yun Oh ; Samuel Bowles ; Bret Beheim ; John Bunce ; Mark Caudell ; Gregory Clark ; Heidi Colleran ; Carmen Cortez ; Patricia Draper ; Russell D. Greaves ; Michael Gurven ; Thomas N. Headland ; Janet D. Headland ; Kim Hill ; Barry Hewlett ; Hillard S. Kaplan ; Jeremy Koster ; Karen L. Kramer ; Frank Marlowe ; Richard McElreath ; David Nolin ; Marsha Quinlan ; Robert Quinlan ; Caissa Revilla-Minaya ; Brooke Scelza ; Ryan Schacht ; Mary Shenk ; Ray Uehara ; Eckart Voland ; Kai Pierre Willführ ; Bruce Winterhalder ; John Ziker
Monogamy appears to have become the predominant human mating system with the emergence of highly unequal agricultural populations that replaced relatively egalitarian horticultural populations, challenging the conventional idea—based on the polygyny threshold model—that polygyny should be positively associated with wealth inequality. To address this polygyny paradox, we generalize the standard polygyny threshold model to a mutual mate choice model predicting the fraction of women married polygynously. We then demonstrate two conditions that are jointly sufficient to make monogamy the predominant marriage form, even in highly unequal societies. We assess if these conditions are satisfied using individual-level data from 29 human populations. Our analysis shows that with the shift to stratified agricultural economies: (i) the population frequency of relatively poor individuals increased, increasing wealth inequality, but decreasing the frequency of individuals with sufficient wealth to secure polygynous marriage, and (ii) diminishing marginal fitness returns to additional wives prevent extremely wealthy men from obtaining as many wives as their relative wealth would otherwise predict. These conditions jointly lead to a high population-level frequency of monogamy.
Interface London : The Royal Society, 2004 Volume 15 (2018), issue 144, article 20180035, Seite 1-15 Online-Ressource
