Nuptiality and fertility in the Dominican Republic

Women in marital unions had more live births than those in consensual unions. The relationship between cumulative fertility and the number of fertile sexual unions is positive for the early childbearing years and negative for the later ones. There is no consistent pattern of relationship between fertility and the sociocultural independent variables for different subgroups according to nuptiality pattern. The relationship between fertility and nuptiality in the Dominican Republic is consistent with that for the Caribbean region.     

Marital fertility in polygynous unions in Nigeria

The effect of polygyny on fertility, by age cohort, was examined in 4 regions of Nigeria through use of data from the 1981-82 Nigerian Fertility Survey. Simple tabulation of numbers of live births by maternal age and type of marriage union indicated that, with the exception of the 30-39-year age group, fertility in polygynous unions tends to be higher than that in monogamous marriages. Overall, such tabulations reveal an average of 3.90 births among polygynous women and 3.47 births among monogamous women. However, when age-specific fertility rates were compared, except for women under 20 and over 40 years of age, rates were higher in monogamous unions (7.286 overall) than for women in polygynous households (7.200 overall). Mean completed fertility, taking into account marriage duration as well, shows a tendency for women in polygynous unions to be more fertile (with the exception of women aged 25-44 years who had been married 10-19 years). The absolute difference in fertility between the 2 types of marital unions ranged from 0.32 children in the northwest to 0.64 in the southeast. With adjustment for independent variables such as education, the absolute mean differences were reduced, from between 0.28 children in the southeast to 0.42 in the northeast, but the direction of high fertility was still in favor of women in polygynous unions. But when the covariates (e.g., age at marriage) were taken into account as well as the independent variables, there was a dramatic reduction in the mean difference between the fertility of these 2 groups of women. These findings suggest that some changes in reproductive behavior are taking place in Nigeria that are restricting the fertility of women in polygynous unions. These changes are hypothesized to reflect the spread of formal education in Nigeria, with the expectation that women will contribute to the costs involved in educating their children.     

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.     

Duration between marriage and first birth and marital instability

This paper considers whether marital instability varies by the duration between marriage and 1st birth among ever-married white and black American women. Analysis of data from the June 1985 Current Population Survey suggests that the duration between marriage and 1st birth has a generally monotonic relationship with the probability of white women separating or divorcing from their 1st marriage; the relationship has remained relatively constant over time. For blacks, no consistent association is found between marital dissolution and the duration between marriage and 1st birth. Black women having a premarital conception and postmarital birth and those having their 1st birth during their 2nd year of marriage have a similarly high risk of dissolution. Conversely, blacks having their 1st birth 8-12 or 25-42 months after marrying have a low probability of dissolution. Childless women and those with premarital births generally has the greatest probability of marital disruption for whites. Racial differences may occur because blacks view the 1st birth and marriage differently than whites. That is, because blacks are much more likely to have premarital births and to have a shorter duration between marriage and 1st birth, blacks and whites in the same 1st birth interval category may be dissimilar and have different values resulting in a differential effect of the timing of the 1st birth on marital instability by race. Caution is needed when interpreting the pattern of association between delayed childbearing (and to a lesser extent, births occuring a few years after marriage) and marital instability. Results for whites were similar at each marriage duration and it is assumed delayed childbearing was not a result of marital instability. Marital instability was expected to have its strongest effect on the timing of the 1st birth during the 1st years of marriage. Marital instability may be partially responsible for the delaying of childbearing among blacks. However, blacks who delay but are married at 1st birth have a relatively low risk of separating or divorcing.     

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.     

Polygyny and fertility differentials among the Yoruba of western Nigeria

Data are analysed from the 1973 surveys of the Nigerian segment of the Changing African Family (CAFN) Project, which covered Yoruba women and men in Ibadan and the Western State of Nigeria. Of the 5874 women who were in union during the CAFN 1 survey, 54% reported that their husband had only 1 wife and 46% that their husband had more than 1 wife. Of the 1234 women in unions in the CAFN 2 survey, 49% reported monogamous husbands and 51% polygynous husbands. Differentials in fertility levels between women in monogamous unions and those in polygynous ones are investigated using mean number of children ever born as the measure of fertility. Factors examined include proportion of childless and infertile women, frequency of intercourse, age, educational level, religion, marital mobility (divorce) rank of wife and sexual abstinence. The CAFN 1 survey shows that wives of polygynists tend to be older than those of monogamists. Because of this the reported mean number of children ever born was higher for the wives of polygynists than for the wives of monogamists. When the data are standardized for the difference in age, the fertility levels of the women in the 2 types of unions were much closer to each other. When religion, education, abstinence, and occupation are also taken into account, it is observed that the 2 groups of women have similar levels of fertility. A multiple classification analysis was performed using number of wives of husband, educational level, religion and father's occupation as variables and occupation of spouse, place of birth, length of abstinence, contraceptive practice and age as covariates. The result also shows that the number of wives of the husband does not significantly affect the fertility level of women when other factors are taken into account. A high proportion of the Yoruba women are in polygynous unions and most of those in monogamous unions are potential wives of polygynists. Because of this, and particularly because most women try to have as many children as they can, the women in the 2 types of unions experience similar levels of fertility.     

Education as policy: the impact of education on marriage, contraception, and fertility in Colombia, Peru, and Bolivia

Using data from the World Fertility and Demographic and Health Surveys of Colombia, Peru, and Bolivia, we model the effects of education on three demographic outcomes: the timing of first sexual union, contraceptive use, and fertility. These effects are examined over time and across geographic areas using a multivariate framework. We find substantial improvements in female educational attainment over the last fifty years and a strong relationship between education and the demographic outcomes. Each successive increment in education is associated with declines in the marriage rate, increased contraceptive use, and lower fertility. Education accounts for some of the changes over time in the demographic outcomes, but the pattern varies by outcome, time period, and geographic area. In support of the social diffusion hypothesis, our results indicate that educational differences in reproductive behavior are reduced as the level of development increases and societies pass through their demographic transition.     

Variations in historical natural fertility patterns and the measurement of fertility control

This paper looks at 2 main issues: 1) Henry's definition of natural fertility--that which is not controlled within marriage in a parity-specific way; and 2) the use of standard age-specific marital fertility schedules to measure the extent of fertility control. The authors note a number of conceptual difficulties inherent in Henry's definition and which detract from its usefulness. In particular, prolonged lactation and taboos against sexual intercourse are capable of depressing fertility within marriage, while still allowing it to be described as natural. This paper explores some of the consequences of the identified difficulties for the measurement of fertility control within marriage. Regional as well as temporal variations are to be expected in the pattern of marital fertility. The factors affecting natural fertility may be broadly divided into the physical and the psychological. Needed are a variety of standard marital fertility schedules specific to the underlying fertility conditions of the particular population under investigation. The universal applicability of a single standard is placed in doubt. The greatest problem, however, with the application of the idea of natural fertility to historical populations is that its definition rests upon a number of behavioral characteristics amongst a population, whereas its identification must normally proceed in reverse, arguing backwards from the pattern observed to the behavioral processes and conditions which might have produced that pattern. The arguments presented are illustrated by a detailed example drawn from the fertility patterns of Britain, Denmark and Sweden.     

Marriage and contraception among the Pare of northern Tanzania

The purpose of the research reported here is to examine the connection between contraception and those aspects of a woman's position that are related to her marriage. The research was conducted in two villages among the Pare of northern Tanzania where a shift from hoe cultivation as primary occupation to wage labour has brought about major changes in social relations. The major hypothesis is that a change from a 'traditional' marital union to a 'companionate' marriage is instrumental in the acceptance of contraception and in lowering fertility. The latter type of relationship between marital partners is related to the status of women. The research methodology consisted of a combination of an ethnographic study, demographic surveys and in-depth interviews. Findings show that approximately half of the women in this community ever used contraception. Of current users, a third are sterilized and half are using a modern reversible method. The determining factor for using modern reversible methods is the nature of the conjugal union.     

Rethinking the Taiwanese minor marriage data: evidence the mind uses multiple kinship cues to regulate inbreeding avoidance

Natural experiments such as the Israeli Kibbutzim and Taiwanese minor marriages provide unique opportunities for testing the effects of childhood association on adult sexual attraction. Within these populations, early childhood association leads to the development of a sexual aversion, an effect first proposed by Edward Westermarck. However, recent analysis of Taiwanese minor marriages indicates that only the age at first association (an inverse index of childhood association) of the younger partner predicts marital fertility rates; the age at first association of the older partner does not. Although considered a puzzle, a recent model of human inbreeding avoidance can explain this pattern. This model suggests that the mind uses at least two kinship cues to regulate the development of sibling sexual aversions: (i) childhood coresidence duration, a default cue used mainly by younger siblings in detecting probable older siblings, and (ii) exposure to one's mother caring for a newborn, a cue only available to older siblings and reliable regardless of coresidence duration and, hence, age at first association. Thus, one reason that the age at first association of only the younger partner in minor marriages predicts fertility is that coresidence duration serves as a cue to siblingship mainly for younger partners; older partners use a different kinship cue not influenced by durations of association. When compared to data from psychological investigations of the effects of coresidence duration on opposition to sibling incest, the minor marriage data reveal an identical pattern providing converging lines of evidence that multiple kinship cues mediate sibling detection and inbreeding avoidance in humans.     

A Bioeconomic Approach to Marriage and the Sexual Division of Labor

Children may be viewed as public goods whereby both parents receive equal genetic benefits yet one parent often invests more heavily than the other. We introduce a microeconomic framework for understanding household investment decisions to address questions concerning conflicts of interest over types and amount of work effort among married men and women. Although gains and costs of marriage may not be spread equally among marriage partners, marriage is still a favorable, efficient outcome under a wide range of conditions. This bioeconomic framework subsumes both cooperative and conflictive views on the sexual division of labor. We test hypotheses concerning marriage markets, assortative mating, and men’s labor motivations among Tsimane forager-horticulturalists of Bolivia and find that: (1) men and women both value work effort in marital partners, (2) marital labor contributions are complementary, (3) work effort is correlated between spouses, (4) total production is correlated with total reproduction, and (5) better hunters have higher fitness gains within marital unions.     

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.     

Age-heterogamy and Canadian union

This study provides a much-needed exploration of the determinants of age-discrepant unions in Canada. What little research has been conducted in this area of sociology of the family is now outdated. Further, the growing number of Canadians living in nonmarital cohabitation warrants their inclusion in any consideration of contemporary, heterosexual unions, and we have done so here. Utilizing multinomial logit modeling techniques, we analyze data drawn from the 1995 Canadian General Social Survey. We find that cohabitations and remarriages are more likely to be age-discrepant than marriages, and that as age at union formation increases, so does the likelihood that the union will be age-heterogamous. Although we hypothesized a positive relationship between education and the chances of age-heterogamous unions because the availability of eligible mates may decrease with education, we actually find an inverse association for women: a one-level increase in education decreases a woman's odds of entering an age-discrepant union by about 4 percent. We speculate that for women, greater education (economic position) may increase age-homogamy because they may be more economically attractive and thus more able to select a partner of their own age.     

The one‐person household in Latin America: A brief note

Abstract

This study provides a much‐needed exploration of the determinants of age‐discrepant unions in Canada. What little research has been conducted in this area of sociology of the family is now outdated. Further, the growing number of Canadians living in nonmarital cohabitation warrants their inclusion in any consideration of contemporary, heterosexual unions, and we have done so here. Utilizing multinomial Iogit modeling techniques, we analyze data drawn from the 1995 Canadian General Social Survey. We find that cohabitations and remarriages are more likely to be age‐discrepant than marriages, and that as age at union formation increases, so does the likelihood that the union will be age‐heterogamous. Although we hypothesized a positive relationship between education and the chances of age‐heterogamous unions because the availability of eligible mates may decrease with education, we actually find an inverse association for women: a one‐level increase in education decreases a woman's odds of entering an age‐discrepant union by about 4 percent. We speculate that for women, greater education (economic position) may increase age‐homogamy because they may be more economically attractive and thus more able to select a partner of their own age.     

Resources and reproductive success in women with an example from the Kipsigis of Kenya

Contradictory results regarding the relationship between resources and reproductive success of women have led some social scientists to conclude that evolutionary biological models are inappropriate to the study of human social behavior. This paper suggests instead that the variability across societies in this relationship reflects an inadequate specification of the nature and availability of the resources critical to reproduction as well as a failure to understand the mechanisms whereby resources confer reproductive success in traditional, developing, preindustrial, and modern societies. These methodological and conceptual issues are illustrated through use of data on the association between wealth and reproductive success from the Kipsigis, a polygynous agropastoralist population in southwestern Kenya. In this society, land is owned by men, and women gain access to land through marriage. In 3 of the 5 marriage cohorts studied, women with access to larger land plots had higher lifelong reproductive success than their poorer counterparts both in terms of enhanced fertility and survivorship of offspring. This association was independent of confounding factors such as education, age at menarche, husband's age, or occupation. Moreover, wealthy women were found not to make greater use of modern medical child health services when their children were sick than poor women. The Kipsigis data indicate that wealthy women had more nutritional resources than poor women and were able to introduce more suitable weaning foods, leading to a lower incidence of episodes of illness in offspring. Overall, the findings suggest that wealth-related differences in the nutrition and health of mothers and children are important factors in reproductive differentials in Kipsigis society.     

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.     

Stable aggregate fertility in a time of family change: a decomposition of trends in American fertility, 1970-1999

Population-level birth rates in the United States were largely stable between 1970 and 1999. This stability contrasts with rapid change in marriage rates and fertility timing during the same period. In this article, I use decomposition techniques to analyze this seeming paradox. I decompose the general fertility rate into four components: age distribution, marital status, age-specific nonmarital fertility, and age-specific marital fertility. Absent other changes, declining time spent married would have led to substantial decline in fertility. Several factors combined to counterbalance these changes in marital behavior. Among white women in the 1970s and 1980s, marital fertility rates increased at older ages, consistent with a scenario in which women postponed both marriage and childbearing; increased nonmarital birth rates during this period were not a driving factor in overall fertility trends. Increased nonmarital fertility was more important in compensating for declining time spent married among African American women and among white women in the 1990s.     

Social characteristics and fertility: A study of Two Religious Groups in Metropolitan New York

Abstract

Reproductive time lost through marital dissolution is a potential factor in decreased fertility. This study of survey data from six Latin America metropolitan areas shows that, among variables examined, type of marital union is the primary determinant of reproductive time lost. The study establishes that appreciably more reproductive time is lost from consensual unions than from legal ones. It also indicates that this difference cannot be explained by such social‐background characteristics as a woman's place of birth or educational attainment.     

Brother-sister and parent-child marriage outside royal families in ancient egypt and iran: A challenge to the sociobiological view of incest avoidance?

Copious and unequivocal evidence of legally condoned and socially favored brother-sister and parent-child marriage among common people from Roman Egypt (first to third centuries, A.D.) and Zoroastrian Iran (fifth century, B.C. to 11th century, A.D.) can be taken to pose a challenge to the sociobiological case for universal evolved incest avoidance within the nuclear family, triggered by early childhood proximity (the Westermarck effect). Official census documents from Roman Egypt show a high incidence of full sibling unions with relatively small age gaps between the spouses and no indication of reduced marital fertility, sexual aversion, or increased infant and child mortality. Zoroastrian religious tracts actively encourage nuclear family incest and extol its meritorious nature and supernatural benefits. A schematic assessment of the likely extent of inbreeding depression in such families under conditions of very high mortality through other causes makes reproduction at replacement level seem difficult to accomplish. But given the lack of information on the frequency of deleterious recessive genes in these populations, this reconstruction is fraught with uncertainty; pertinent ancient evidence is suggestive of some incidence of inbreeding depression but remains inconclusive. Aversion and revulsion between incestuous spouses proves a similarly elusive issue. Although these cases from antiquity do not clearly contradict the view of incest avoidance as an evolved mechanism that engenders sexual indifference and normally translates into corresponding cultural norms, they demonstrate the need for a more comprehensive consideration of the available historical record in the testing of evolutionary rules.