Seasonality of births and conceptions in a pastoral community of the province of l'Aquila (Abruzzo,Italy), 1802-1965

Natality rates and seasonality of births and conceptions were analyzed from 6,116 birth records in the pastoral community of Roio (Abruzzo, Italy) from 1802 to 1965. Gross natality rates averaged 25.5 x 1000 in the past, lower than those reported for agricultural groups. Seasonality of births showed a marked pattern: 807-67% of births occurred in the first six months of the year. The monthly distribution of conceptions was compared to that of marriages. The results show a high correlation in the 19th century and a lower one in the 20th century. These findings suggest that pastoralism acted as a primary regulator of reproduction in this community.     

Polygyny and fertility in Morocco: the effect of marital instability

This paper analyses the relationship between polygyny and female fertility in the province of Marrakech (Morocco) taking into account the effect of the previous marital instability (number of marriages) and the possible association between female sterility and type of marriage. In the analysed population, polygyny increases in the small towns. Polygynously married women have a higher level of education and show a higher percentage of use of contraceptive methods than the monogamously married ones. Although polygynously married women initially show lower fertility, multivariate analysis carried out on the group of women between 35 and 49 years old show that there are no significant differences in fertility between monogamously and polygynously married women when the effect of the previous marital instability is considerer. Female sterility does not determine marital instability, although it does determine a significant increase in polygynous marriages among the women without children.     

Reproductive isolation in Roio,a pastoral community of the Province of L’Aquila (Abruzzo,Italy) in the period 1800–1965

The present work refers to the study of reproductive isolation in Roio, a pastoral community in the Province of L’Aquila (Abruzzo), as part of a research project aimed at studying human isolates in the Central Apennines from an ecological viewpoint. Results relating to 1470 records of marriages from parish books show: 1) rates of endogamy around 80% in both centuries, the lowest so far found in the Province of L’Aquila. 2) Rates of consanguineous marriages average 12% in both centuries with an increasing trend in the period 1860–1930. 3) Inbreeding coefficients are 3–3.5×10⁻³ on average in both centuries, the highest so far found in the Province of L’Aquila, with the maximum value of 5.3×10⁻³ in the period 1880–99. Of relevance is the contribution of marriages between 1st and 2nd cousins in all periods and of oncle/neice and multiple consanguinity at the turn of the century. 4) Rates of isonymous marriages are 5.4% and 10% in the two centuries. 5) Inbreeding coefficient Ft is 0.0137, on average, in the 1800s and 0.025, almost doubled, in the 1900s. Its progressive increase with time is due both to the random and non-random components, thus suggesting increasing conditions of isolation and drift and a persistent tendency of celebrating unions between relatives.     

Leaving your wife and your brothers: when polyandrous marriages fall apart

Polyandry challenges both traditional sociocultural and evolutionary understandings of marriage. Its existence calls into question the importance of female sexual exclusivity and reproduction in marriage, two fundamental aspects of the affinal bond in most other marital forms. How does polyandrous marriage persist? When does it dissolve? This paper examines marriage patterns in the fraternally polyandrous Tibetan communities of northwestern Nepal, highlighting the most important factors associated with both the maintenance and dissolution of polyandrous unions. Behavioral ecological analyses of polyandry to date have focused on univariate analyses of the economic and fertility correlates of the two primary marital forms observed in nominally polyandrous communities, polyandry and monogamy. In this analysis, multivariate regression and survival analysis are used to extend our understanding of the factors that precipitate partitioning among the polyandrous marriages in the study. Wealth, long thought to be a major force shaping marital decisions in these communities, is modeled in both quantity and quality in this study. This represents an important departure from previous studies, as analyses show that it is not only the amount of wealth that influences the stability of polyandrous marriages, but also the type of wealth and extent to which it is diversified over economic spheres. Univariate analyses show that amount of wealth and the size of the brother/co-husband set are both associated with the probability that a polyandrous marriage will partition. Though these results support earlier findings, multivariate analyses show that controlling for other factors reduces their importance.     

Differentials of fertility between polygynous and monogamous marriages in rural Bangladesh

This paper discusses polygynous marriages in rural Bangladesh, using marital status and birth registration data from the Demographic Surveillance System (DSS) of the International Center for Diarrheal Disease Research, for the period 1975-79. Of all the marriages recorded during this period about 5% were polygynous. To identify the women polygynously married, 1974 census data of the DSS area were used. The difference in age at marriage between the polygynous groom and his subsequent wife was 15 years on average. The socioeconomic indicators studied were education, occupation and area of dwelling space. In general, these indicators between women in monogamous marriages were significantly higher than between the women in polygynous unions. During the period 1976-79, 863 polygynous marriages were recorded (4.9% of all marriages in the study area). Polygynous marriages were found to be less frequent among men with 2ndary and higher levels of education. The highest proportion of polygynous marriages occurred among husbands with no schooling or Koranic education. The general fertility rate of women in monogamous marriages was significantly higher than for women in polygynous marriages, overall and in all age groups except 20-24. During the period 1975-79, the mean number of liveborn children for monogamous women was higher than that of polygynous women.     

>For better or worse, till death us do part<--spousal age gap and differential longevity: evidence from historical demography

Based on a set of 2,371 family related entries dating from 1688 to 1921, the current study tried to verify longevity differentials due to interspousal age difference. For the purpose of the analysis, age-heterogamy was operationalized in terms of sample-specific marital age gap (3.2 years) with a standard deviation of 6.1 years. Based on this, five marriage groups were isolated. Female mean age at marriage experienced a slight increase over time, while the male mean at marriage decreased. This led to an appreciable narrowing of the spousal age gap. Age-homogamous unions were most prevalent in the lower socio-economic class (day-laborers, industrial workers) (p<0.01). In both husband-older and wife-older unions, the interspousal gap increased with marriage order. In accord with previous studies, mean age at death varied significantly by marriage group. Females, who married younger men, died later than females, who married older men. In contrast, male longevity was most depressed within age-similar marriages, while those who married older or younger wives displayed higher life spans. Overall, marriage to a younger spouse seemed to increase longevity prospects (p<0.05). These differentials were not exclusively a function of the marital age gap, but were affected by diverse confounders such as reproductive output and socio-economic status.     

The use of parish marriage registers in biodemographic studies: two case studies from 19th-century Italy

No previous studies have critically evaluated the representativeness or reliability of parish marriage registers for biodemographic studies of historical Italian populations. Because of the widespread Italian custom of spouses settling down in the groom's parish after getting married in the bride's, such registers do not contain any information on wife-exogamous unions. This fact affects not only the number of marriages considered, but also any estimates of the biodemographic parameters usually assessed in these types of studies, especially when open populations are considered. Due to the richness of the parish archives for two populations in central Italy, it was possible to retrieve from the Status Animarum (Register of Souls) information concerning the missing data regarding marriages. Consequently, it was possible to compare values of marital structure indices obtained using only data from marriage registers with the corresponding figures computed using either the complete data series of marriages or solely that of resident couples. The results demonstrate the existence of significant variations in the figures for the exogamy rate, as well as in the number of new family names introduced by marriage. In addition, F and RP values showed important but nonhomogeneous variations.     

Polygamy and fertility in Somalia

The 1983 Somali Family Health Survey showed that polygamy and monogamy selected women with different social characteristics. Wives in polygamous unions were prone to be younger at first martial cohabitation and to have previous marital disruptions. Since a young age at first cohabitation and number of previous marriages have opposite effects on the cumulative fertility rate of women, the difference in this rate between wives in polygamous and monogamous unions vanished when both factors were controlled in a multivariate analysis.     

The practice of consanguineous marriage in oman: prevalence, trends and determinants

The practice of consanguineous marriage has been the culturally preferred form of marriage in most Arab and the Middle Eastern countries, including Oman, but due to a paucity of population-based data in the past there is a dearth of information about its form and dynamics in Oman. Recent national-level surveys allow this gap to be filled. This paper examines the prevalence, trends and determinants of consanguineous marriages in Oman using data from the 2000 Oman National Health Survey. The results indicate a very high prevalence of consanguineous marriage in Oman, as more than half (52%) of marriages are consanguineous. First cousin unions are the most common type of consanguineous unions, constituting 39% of all marriages and 75% of all consanguineous marriages. The study observed various patterns of consanguinity, some of them common with other Arab nations, and some unique in nature. Women's age at marriage, employment, place of childhood residence and geographical region appear to be significant determinants of consanguineous marriages. Consanguineous marriage shows a strong association with marital stability, early age at marriage and early-age childbearing. There has been no appreciable change in the prevalence of consanguineous unions in Oman over the last four decades despite massive socioeconomic development and modernization. However, recent marriage cohorts show slight declining trends. The results suggest that consanguinity is likely to remain stable in the future or decline at a slow rate. Specific health education and genetic counselling should be followed in line with WHO recommendations to minimize the negative health consequences of consanguinity for child health.     

Community perceptions of reasons for preference for consanguineous marriages in Pakistan

Although the recent Pakistan Demographic and Health Survey (DHS) show that two-thirds of marriages in Pakistan are consanguineous, the sociocultural determinants of such marriages remain largely unexplored. This paper examines the relative importance of the three commonly perceived reasons for such marriages: religious, economic and cultural. The analysis is based on qualitative data collected in 1995 from multi-ethnic and multi-religious communities in Karachi, the largest city of Pakistan. Results show that consanguineous marriages are preferred across all ethnic and religious groups to a varying degree, and that parents continue to be the prime decision-makers for marriages of both sons and daughters. The major reasons for a preference for consanguineous marriages are sociocultural rather than any perceived economic benefits, either in the form of consolidation of family property or smaller and less expensive dowries. Among Muslims, following religious traditions is the least commonly cited reason for such marriages. Despite the reported sociocultural advantages of consanguineous marriages, such unions are perceived to be exploitative as they perpetuate the existing power structures within the family.     

Legalization of consensual unions in Latin America

Abstract

In Latin America conjugal unions take two forms, legal marriages and consensual unions. The distinction between these two types of unions is complicated by the fact that cohabiting couples often legalize their relationship through civil or religious marriage. This analysis examines legalization in rural areas of Colombia, Mexico, Peru, and Costa Rica based on data from the PECFAL rural survey (1969). The results indicate that legalization is frequent in rural Latin America, especially among women who enter consensual unions after age 17 and who have some education. Surprisingly, there is little increase in the frequency of legalization for church‐attending Catholics or for women who have a pregnancy or birth within a consensual union. Consensual unions appear to serve a useful function as trial marriages since legalized unions are less likely to end in separation than are legal marriages without premarital cohabitation.     

Effects of consanguineous marriages on fertility among three endogamous groups of Andhra Pradesh

To assess interrelationships between consanguineous marriage and fertility, 3 caste groups in Andhra Pradesh--the Desuri Kapu, an affluent agricultural caste; the Devanga, an artisan caste in the middle range of the hierarchy; and the Mala, a scheduled caste at the bottom--were selected for field study. Consanguineous marriages are an essential part of the social structure in this area of southern India. A total of 2524 marriages were analyzed, of which 46% were consanguineous. 19% of consanguineous marriages were between uncle and niece, 22% were between 1st cousins, and 5% were between more distant cousins. The Devanga had the highest rate of related marriages (48%), followed by the Desuri Kapu (47%) and the Mala (41%). Higher caste individuals, and wealthier persons within each caste, are more likely to marry relatives so they can avoid splitting their properties through dowry of bride price. The consanguineous unions as a whole were significantly more fertile than nonconsanguineous unions. The mean number of pregnancies, live births, and surviving offspring was 4.85, 4.44, and 2.99, respectively, among consanguineous couples compared with 3.41, 3.32, and 2.87, respectively, among nonconsanguineous couples. Although the number of pregnancies and live births was significantly higher among consanguineous couples in all 3 castes compared with nonconsanguineous couples, the difference in the number of surviving children between consanguineous and nonconsanguineous unions was not significant among the wealthier castes. This suggests that child mortality is higher among the offspring of consanguineous unions, despite their greater wealth.     

Correcting contraceptive failure rates for sample composition and sample selection bias

Abstract

There is reason to believe that in the short run marriages are becoming more stable in some Western African countries such as Cameroon. One of the crucial questions facing these countries is whether fertility rates can be expected to increase or decrease due in part to the increased stability of marriages. Analyzing 1978 Cameroon World Fertility Survey data and using a multivariate regression model which compares the fertility rate of women who have had at least one marital disruption with that of continuously married women, we studied the relationship between marital instability and fertility. The results show that fertility rates for women married more than once are significantly lower than those for continuously married women even before the end of their first marriage. Furthermore, marital disruption significantly reduces fertility rates after the dissolution of the first marriage. Finally, even after the length of reproductive time lost is controlled, there is an inverse relationship between the number of marriages and fertility. The results are discussed in the context of economic development, modernization, and urbanization.     

Analysis of marital structure in Massachusetts using repeating pairs of surnames.

Analysis of surnames from marriages is now a well-established method in the study of marital and genetic structure. Traditional methods of partitioning inbreeding into random and nonrandom components rely on the total number of isonymous marriages. Because this number is often low, standard errors of inbreeding estimates tend to be high. Lasker and Kaplan (1985) devised a method that circumvents this problem by focusing on the total number of repeating pairs (RP) of surnames among marriages. The observed value of RP can be compared with the value expected at random (RPr) to assess patterns of subdivision within a population. The RP method is applied here to data from 3431 marriages that took place from 1800 to 1849 in 4 Massachusetts towns. The level of excess RP [(RP-RPr)/RPr] is positively associated with population size and exogamy rate. These results indicate a tendency for greater relative subdivision in larger, more exogamous populations. One possible reason for increased subdivision is preferential marriage by social class, although adequate data are not available for a test of this hypothesis.     

Geographic, demographic and inbreeding patterns in a Basque mountainous region of Guipuzcoa

The Goierri, a mountain region within the Basque Hills of Guipúzcoa, includes one of the most culturally controlled autochthonous populations within the Basque area, mainly from linguistic point of view. The effects of geography and demographic changes (1862–1995) on consanguinity variables over its 21 Municipalities have been investigated. Rates of consanguineous marriages and mean inbreeding levels recorded in some of the southern villages can be considered high but, average values for the entire region were lowered due to the early industrialization of the province. In spite of that, consanguinity in the study area has been, for a long time, a prevailing and conspicuous phenomenon when compared to the other Guipúzcoa regions. The impact of marriages between first cousins from immigrant groups on the regional inbreeding levels represents an interesting result as well. Geographic and demographic factors seem to be related both to the extent of marriages as well as to the number of potential mates within populations, which, in turn, are associated with mean inbreeding levels. Altitude seems to show weak relationship with population distribution and population consanguinity variables. Nevertheless, levels of endogamy appear positively correlated with consanguinity rates and mean inbreeding coefficient and, inversely related-but not statistically significant- to mean village sizes. First cousin marriages yield the highest levels of exogamy and exogamous M22 marriages were mostly concentrated within short (1–10 km) and long-range marital distances (>50 km). The aveaage values of Goierri have been compared with a consanguinity data set of some selected Spanish mountain populations taken from the literature. One of the main results is that geographic and demographic variables are poorly correlated with the most important inbreeding parameters. However, different clusters of populations can be observed with specific characteristics for each of them, not highly correlated with geography.     

Consanguineous marriages in Beirut: Time trends,spatial distribution

Abstract

Twenty‐five per cent of all marriages are consanguineous in a population‐based sample of couples from Beirut. Marriages between distant relatives decline with time, while first‐cousin marriages remain relatively stable. Among first‐cousin marriages, the proportions of father's brother's daughter marriages (37 per cent) and of patrilateral unions (48 per cent) are particularly low. A spatial representation demonstrates an uneven distribution of consanguineous marriages, and an association of high levels of endogamy with Muslim religion, low educational level, and low occupational status.     

Same Sex Marriage and the Perceived Assault on Opposite Sex Marriage

Background

Marriage benefits both individuals and societies, and is a fundamental determinant of health. Until recently same sex couples have been excluded from legally recognized marriage in the United States. Recent debate around legalization of same sex marriage has highlighted for anti-same sex marriage advocates and policy makers a concern that allowing same sex couples to marry will lead to a decrease in opposite sex marriages. Our objective is to model state trends in opposite sex marriage rates by implementation of same sex marriages and other same sex unions.

Methods and Findings

Marriage data were obtained for all fifty states plus the District of Columbia from 1989 through 2009. As these marriage rates are non-stationary, a generalized error correction model was used to estimate long run and short run effects of same sex marriages and strong and weak same sex unions on rates of opposite sex marriage. We found that there were no significant long-run or short run effects of same sex marriages or of strong or weak same sex unions on rates of opposite sex marriage.

Conclusion

A deleterious effect on rates of opposite sex marriage has been argued to be a motivating factor for both the withholding and the elimination of existing rights of same sex couples to marry by policy makers–including presiding justices of current litigation over the rights of same sex couples to legally marry. Such claims do not appear credible in the face of the existing evidence, and we conclude that rates of opposite sex marriages are not affected by legalization of same sex civil unions or same sex marriages.     

Maternal age at last birth in Egypt

To assess the effects of women's education, residence, and marital experience on their age at the birth of their last child, a proportional hazards regression model was applied to 1980 Egyptian Fertility Survey (EFS) data. The detailed data include the date of birth of each child for every women interviewed, and the woman's date of birth and age at interview. Age at last birth was examined by regression analysis on birth history and socioeconomic information. 4 hypotheses were tested: women who are well educated have a greater probability of ending childbearing earlier than women with less education; women in rural areas have a higher probability of having their last child at older ages than urban women; marital disruption without remarriage lowers the probability of older maternal age at last birth; and marital disruption with remarriage increases the probability that a woman stops reproducing at an older age. The overall chi-square indicates a significant regression. All coefficients were significant, except the coefficient for women with intact 1st marriages. Women with more education had a greater probability of ending childbearing earlier than women with less education. Rural women tended to have their last children at ages significantly older than overall age at last birth. Current residence in urban areas had the opposite effect. The coefficient for those with intact 1st marriages was insignificant, meaning that the mean age at last birth for this group of women was not much different from the overall mean. Remarried women tended to end childbearing at ages significantly older than the overall average age at last birth, suggesting that these women tended to have children by their new husbands. Those with dissolved 1st marriages who had not remarried had a higher probability of ending childbearing earlier than did older women. Marriage age and final parity had highly significant negative coefficients; as marriage age and number of children born increased, so did the "survival" time or the age at last birth. Results from the hazards model indicate that the effects were as anticipated. The median age at last birth for the total sample of women aged 45-49 was 45-49 years. The median age at last birth was about 2 years older for rural compared to urban women. Illiterate women had the oldest median age at last birth of the education groups. There was little differences between median ages at last birth for women with intact 1st marriages and those whose 1st unions were dissolved and who had remarried. The median age at last birth increased with final parity.     

Sociodemographic correlates of consanguineous marriage in the Muslim population of India

Using data derived from the 1992-1993 National Family Health Survey, the sociodemographic characteristics of consanguineous marriage were determined in the Muslim population of India. In this nationally representative sample of 8436 women, consanguineous marriages accounted for 22.0% of the total. No differences between the consanguineous and non-consanguineous groups were observed in terms of mean age at marriage or mean age at cohabitation. The study confirmed the negative association between consanguineous marriage and maternal education but also indicated that women in consanguineous unions were more likely to be employed, albeit mainly in agricultural work on behalf of the family. Consanguineous couples more frequently lived in smaller towns and in an extended family environment. Somewhat conflicting results were obtained with indicators of socioeconomic status, but the overall picture suggested that consanguineous households had greater access to consumer goods because of their larger number of co-resident persons.