Social and biological determinants of age at first marriage in Taiwan, 1970

Abstract

This study examines the social and biological determinants of age at first marriage in two townships in northern Taiwan, one very rural and traditional and the other urban and modernized. For a sample of 5,707 once‐married women a path analysis was performed in which age at first marriage was considered a function of age, educational attainment, urban origin, premarital labor‐force participation, and age at menarche. Age at menarche, with a positive effect on the dependent variable, was the most important direct cause of age at first marriage. Although exogenous variables associated with modernization (urban origin, educational attainment and younger age) had a positive direct effect on age at first marriage, they also had a negative indirect effect on age at first marriage through their negative direct effect on age at menarche.     

Consanguinity: Geographical variation and temporal evolution in the North of the Iberian peninsula, 1918–1968 (León,Spain)

We studied 71.740 marriage certificates from the Diocese of León, Northern Spain, between the years 1918 and 1968. If VI degree marriages are considered 6.27% of the total were among relatives. The inbreeding coefficient is very near the average for other Spanish populations from the same period (F=0.002). Within the area studied, levels of inbreeding are higher in rural than in urban zones and slightly higher in the montaña than in the meseta. Within the montaña it is higher in the non-mining zone of the North than in the mining zone of the South. Throughout the entire period under study there is a continuous tendency towards a decrease in inbreeding which is sharper in the rural than in the urban zone. Consequently there is a convergence of values in recent times. This tendency appears later in rural populations in the center of the peninsula than in those of northern Spain, and in the Spanish population later than in other European countries.     

Differential fertility in Bangladesh: A path analysis

Abstract

This study attempts to show both theoretically and empirically the causal links between selected background, socioeconomic, and demographic variables, on the one hand, and between these variables and cumulative fertility, on the other. Two distinct models, urban and rural, emerge as a result of a statistical test. In both models, neither wife's nor husband's childhood background is found to have any significant direct effects on fertility. Wife's age, religion, and age at marriage are the common variables which directly affect the number of children ever born. While age and religion bear positive direct effects, age at marriage exerts a negative direct effect. The indirect effect of religion is positive both in the rural and urban area. Both the direct and indirect effects of wife's education on fertility in urban Bangladesh are negative. Husband's education, in contrast, has a positive direct effect in the urban area and no effect at all in the rural area.     

云南九个民族中的近亲结婚调查

对云南9个民族[傣、哈尼、彝、布朗、基诺、拉祐、苦聪(人)、回、汉]共11,589起婚姻作了调查。发现:(1)城、乡之间,各民族与地区之间,近婚率差异极显著。(2)许多民族的近婚率均较国内发达地区同一民族高。(3)姑舅亲、倒姑舅、两姨亲及3/2表亲占9个民族近婚总数的84.7％。(4〕9个民族的平均近交系数同样较国内发达地区同一民族高,其中苦聪人的平均近交系数(0.018579)是目前国内最高数值之一,即使平均近交系数最低的汉族(0.001935)也明显高于北京、湖北宜昌和上海市区的汉族的平均近交系数。     

A comparative study of determinants of uxorilocal marriage in two counties of China

Abstract

A strictly maintained patrilineal family system makes virilocal marriage almost universal and uxorilocal marriage rare in the history of rural China. Uxorilocal marriage can be divided into two types that may be termed, respectively, contingent and institutional. The former preserves family lineages in families without a son and occurs when uxorilocal marriage is uncommon. The latter serves practical economic purposes in families with sons and occurs when uxorilocal marriage is relatively prevalent. Using data from a survey in two counties of Shaanxi—Lueyang, where both kinds of uxorilocal marriage are prevalent, and Sanyuan, where uxorilocal marriage is rare and usually contingent—this paper employs logistic regression models in a quantitative comparative study of determinants of uxorilocal marriage in rural China. We show that the purposes and prevalence of the two types of uxorilocal marriage differ and that their determinants are also different in the two counties. In Sanyuan, the determinants are only a couple's sibling composition, membership in a large family clan, and educational level. In Lueyang, in addition to those determinants in Sanyuan, important contributions to the type of uxorilocal marriage include a couple's parental marriage type, age at marriage, adoption status, marriage arrangement, and their attitudes toward uxorilocal marriage. The results indicate the potential importance of encouraging uxorilocal marriage in rural areas as a means of mitigating demographic and social problems related to son preference, such as high sex ratio at birth and lack of old‐age security, which are projected for China's future.     

Assessing the correlates of desired family size in Shaanxi,China

Abstract

This exploratory analysis of factors associated with Chinese women's fertility desires uses data on married women between the ages of 18 and 35 who live in Shaanxi Province, China. Analyses using an economic framework found that both rural and urban couples who intended to sign, or who had already signed, the one‐child certificate reported wanting significantly fewer children. However, in rural areas (where 80 per cent of the provincial population lives), education level, living arrangements, participation in an arranged marriage, attitudes regarding the ideal age for marriage, and knowledge of the reasons for the government's fertility policies appear to play a relatively larger role in shaping fertility preferences.     

Individual dietary specialization in a generalist predator: A stable isotope analysis of urban and rural red foxes

Some carnivores are known to survive well in urban habitats, yet the underlying behavioral tactics are poorly understood. One likely explanation for the success in urban habitats might be that carnivores are generalist consumers. However, urban populations of carnivores could as well consist of specialist feeders. Here, we compared the isotopic specialization of red foxes in urban and rural environments, using both a population and an individual level perspective. We measured stable isotope ratios in increments of red fox whiskers and potential food sources. Our results reveal that red foxes have a broad isotopic dietary niche and a large variation in resource use. Despite this large variation, we found significant differences between the variance of the urban and rural population for δ¹³C as well as δ¹⁵N values, suggesting a habitat‐specific foraging behavior. Although urban regions are more heterogeneous regarding land cover (based on the Shannon index) than rural regions, the dietary range of urban foxes was smaller compared with that of rural conspecifics. Moreover, the higher δ¹³C values and lower δ¹⁵N values of urban foxes suggest a relatively high input of anthropogenic food sources. The diet of most individuals remained largely constant over a longer period. The low intraindividual variability of urban and rural red foxes suggests a relatively constant proportion of food items consumed by individuals. Urban and rural foxes utilized a small proportion of the potentially available isotopic dietary niche as indicated by the low within‐individual variation compared to the between‐individual variation. We conclude that generalist fox populations consist of individual food specialists in urban and rural populations at least over those periods covered by our study.     

Social and biological determinants of age at first marriage in Taiwan, 1970

This study examines the social and biological determinants of age at first marriage in 2 townships in Northern Taiwan, one very rural and traditional and the other urban and modernized. Using a sample of 5707 once-married women, a path analysis examined age at first marriage as a function of age, educational status, urban origin, premarital labor force participation, and age at menarche. Age at menarche, with a positive effect on the dependent variable, was the most important direct cause of age at first marriage. This biological factor is interrelated with socioeconomic influences as predictors of age at marriage. Older cohorts of women tended to marry about 2 years earlier than did the women below 30. Urban women had a mean age at first marriage 1.76 year later than did rural women. Age at marriage steadily increases as education increases; a 4 year age differntial exists between those who have no formal education and those who have at least 12 years of education. Also, women who worked before marriage married later than those who had never worked. This study reemphasizes that in Taiwan, as elsewhere, there is a complex interplay of socioeconomic and biological factors embedded within a cultural context that influences age at first marriage for females.     

Book notes

Abstract

Marriage in Indian society is a religious duty. Consanguineous marriage is common, where individuals prefer to marry within their clan (a unilateral kin group based on either matrilineal or patrilineal descent). Keeping in mind that this form of marriage has certain disadvantages for social and biological as well as demographic aspects of individuals and families, the present study examines the influence of mate selection (i.e., close relatives, distant relatives, not related) on female age at marriage, pregnancy wastages, and survival status of the first child. The study was designed based on the information collected on a sample size of 3,948 married women aged 13–49 in Tamil Nadu, India, by the National Family Health Survey (NFHS), 1992. Results suggest that 48 per cent of women in Tamil Nadu marry their relatives. This practice of marrying relatives is high in rural areas, among Hindus, Scheduled Castes/tribes, and illiterate women as compared to urban areas, among non‐Hindus, non‐SC/ST, and educated women, respectively. The bivariate analysis reveals that women marrying their close relatives had low age at marriage and experienced a higher per cent of pregnancy wastage and child loss (first child) as compared to those women marrying their distant relatives or nonrelatives. The result is found to be consistent even after controlling for selected background variables through multivariate techniques (applied separately for age at marriage, pregnancy wastages, and the survival status of first child). Hence, this study suggests that steps should be taken to inform people about the problems of marrying close relatives through appropriate IEC programs in Tamil Nadu.     

Consanguineous marriages in the province of Antalya, Turkey

To assess the trends in the frequency and the medical effects of consanguinity in the south coast of Turkish population using local and national data in the last 11 years. This cross-sectional study was carried out in Manavgat province, which is a major tourism center on the Mediterranean coast of Turkey. The authors studied consanguineous marriages in rural and urban population in the Mediterranean coast, Manavgat province, Turkey, via a 1500 random survey sample of married couples. There has been a significant increase in the incidence of consanguineous marriages in rural areas (40.7%) since 1989 in the southern population of Turkey. The results showed that the most frequent type of marriage was between the first cousins. It is found that there is no statistically significant difference between the consanguineous and non-consanguineous marriages in the different age groups. The results were discussed on the basis of educational status, reasons for having consanguineous marriages and the general medical effects as well as with the relation of congenital malformations. The custom of consanguineous unions in the Mediterranean population of Turkey is still extremely high, and preventive measures should be done to decrease its frequency and associated complications.     

Investigating environmental variation and landscape characteristics of an urban–rural gradient using woodland carabid assemblages

Aim To investigate environmental variation and associated assemblage changes of carabid beetles along an urban–rural gradient. Location ‘Quercus–Acer’ (oak–sycamore) woodlands in the city of Birmingham, UK. Methods We collected carabid data using pitfall traps on 12 sites in the city. The traps were run from April–September in 2000, and we collected environmental data on 24 individual variables associated with the individual sites and their landscape context. Changes in carabid assemblages were analysed using repeat measures anova and the environment–species relationships with a Redundancy Analyses (RDA) and Generalized Linear Modelling (GLM). Results We found that: (1) species richness and diversity were lower in the urban and suburban zone and higher in the rural zone; (2) Berger Parker dominance index was higher in the urban and suburban zones; (3) the number of woodland and woodland associated species was significantly higher at the rural end of the gradient; (4) the number of short‐winged (brachypterous) species was highest in the rural zone and decreased towards the urban woodlands, whereas the long‐winged species were more abundant in suburban woodlands; (5) the median weight length (WML) of the assemblage declined along the gradient from the rural to the urban zone, as did the number of large species; and (6) five of the 24 environmental variables showed a significant relationship with variation in the carabid assemblage. At site level the carabid assemblages were related to the level of site disturbance and soil penetrability, whereas site size and amount of woodland and urban land within 5 km of the site were important at a larger landscape scale. Main conclusions The results suggest that urbanization has a deleterious impact on carabid assemblages, causing a reduction in species richness from the rural fringe to the centre of the city. Changes in assemblage structure were related to woodland fragmentation, which led to variations in woodland size, woodland location and site disturbance due to trampling. Large, flightless and specialist woodland species are more susceptible to changes associated with urbanization, presumably due to their longer life spans, lower reproductive rates, more specialized niches and more limited dispersal potential.     

Age at return marriage and timing of first birth in India's Uttar Pradesh and Kerala states

Abstract

The study investigates the relationship between age at marriage and the length of first birth interval in two states of India: Uttar Pradesh and Kerala. Life tables of first‐birth intervals and median first‐birth intervals are computed for several subgroups of the study population. Multivariate hazards modelling technique is used to study the net effect of age at marriage, controlling for a multiple of socioeconomic factors. The result shows that the average first‐birth interval varies by age at marriage and is much longer in Uttar Pradesh than in Kerala.     

Marriage ethnic assortative mating of urban and rural population of Karachay-Cherkessia

This paper presents analysis of 28879 marriage records from 1990–2000 (total sample). Ethnic marriage assortative mating is positive in all ethnic groups significantly represented in Karachay-Cherkessia; the lowest values are characteristic of the more numerous ethnic groups (Karachays and Russians). The rate of metisation of the urban population is 21.6%; the rate for the rural population is 16%; the values vary significantly for different ethnic groups, reaching 98% for urban Ukrainians. With this rate of gene exchange, half of the urban population becomes interbred after three generations, and half of the rural population after four.     

Consanguineous marriage and differentials in age at marriage, contraceptive use and fertility in Pakistan

Fertility rates in Pakistan have remained consistently high over the past three decades. While numerous studies have examined sociodemographic determinants, the role of biological factors, and particularly consanguinity, has received little attention, even though marriage between close biological relatives continues to be the norm in Pakistan. Reproductive behaviour among women in consanguineous (first cousin) and non-consanguineous unions was compared, using data from a 1995 study of multi-ethnic communities in Karachi and the 1990-91 Pakistan Demographic & Health Survey (PDHS). The results show that, although female age at first marriage has been gradually rising in both study samples, women in consanguineous unions married at younger ages and were less likely to use modern contraceptive methods. In the Karachi sample, women in first cousin unions experienced a higher mean number of pregnancies and also reported a higher mean number of children ever born (CEB). However, their mean number of surviving children did not differ from those born to women in non-consanguineous unions, implying higher prenatal and/or postnatal losses in couples related as first cousins. On the other hand, the PDHS showed both lower CEB values for women in consanguineous marriages and a lower number of surviving children. Given the continuing popularity of consanguineous marriage, these findings have important implications for future fertility reduction in Pakistan.     

Age‐discrepant marriages: Cross‐national comparisons of Canadian‐American trends

Abstract

Comparisons of age‐discrepant marriages ideally involve data which are collected at the time of marriage and which are available by single years of age for the same population over time. Although such data are not available for Canadian‐American comparisons, approximations of them are derived from the United States census, from marriage statistics (including statistics for California and for British Columbia), and from selected fortuitous studies of age at marriage. Although available data are not conclusive, they suggest that Canada and the United States do not differ markedly in the incidence of age‐discrepant marriages and that both exhibit longitudinal trends which reflect a decreased incidence of marriages with large husband‐wife age differences and an increased preference for coeval marriages, but exhibit markedly little change in the incidence of wife‐older marriages. Cross‐cultural patterns of age‐discrepant marriages are suggested as an unobtrusive indicator for comparative assessments of the de facto status of women.     

The marriage squeeze in Colombia, 1973–2005: The role of excess male death

Abstract

Colombia has been characterized by extreme levels of civil violence throughout the latter part of the twentieth century, and the burden of excess mortality attributable to this violence has been borne primarily by young men. Populations with a large violent death burden are likely to experience consequences in terms of (1) marriage markets, (2) the dynamics of family formation and dissolution, and (3) patterns of parental investment in offspring. Using data from national censuses and household surveys, we calculate a measure of the marital sex ratio in order to explore the impact of differential male mortality on marriage markets in Colombia. Overall, Colombia is characterized by a female biased sex ratio at all ages. This relative excess of women is particularly pronounced in certain departments of the Central and Pacific regions which have been especially affected by civil violence. We suggest that the low sex ratios which characterized Colombia are partially responsible for the increasingly high frequency of consensual unions and, potentially, female‐biased rural‐urban migration.     

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.     

The prevalence and correlates of consanguineous marriages in Yemen: similarities and contrasts with other Arab countries

Using data on 9762 women from the 1997 Yemen Demographic and Maternal and Child Health Survey, this paper examines the prevalence and socioeconomic correlates of consanguineous marriages in Yemen. The results indicate that 40% of marriages are consanguineous, over 85% of which are between first cousins. The prevalence of consanguineous marriages appears to have increased over time, particularly for the last marriage cohort. As for socioeconomic correlates, the study confirms the inverse association between consanguineous marriages and women's education and occupation, age at marriage and economic status. However, no statistically significant difference in the prevalence of consanguinity has been found by place of residence and geographical region. Somewhat unexpected results have been obtained by husband's background characteristics, with higher educated men and those working in the modern sector of the economy being more likely to be married to cousins.     

Impact of Land-Use Patterns on Chemical Properties of Trace Elements in Soils of Rural,Semi-Urban,and Urban Zones of the Niger Delta,Nigeria

The study of the concentrations of Cr, Zn, Cd, Pb, Ni, and Cu in soils under different land uses in rural, semi-urban, and urban zones in the Niger Delta was carried out with a view to providing information on the effects of the different land uses on the concentrations of trace elements in soils. Our results indicate significant variability in concentrations of these metals in soils under different land uses in rural, semi-urban, and urban zones. The maximum concentrations of metals in the examined soil samples were 707.5 mg.kg^?1, 161.0 mg.kg^?1, 2.6 mg.kg^?1, 59.6 mg.kg^?1, 1061.3 mg.kg^?1, and 189.2 mg.kg^?1 for Cr, Zn, Cd, Pb, Ni, and Cu, respectively. In the rural zone, the cassava processing mill is a potent source of Ni, Cr, Cu, and Zn while agricultural activities are a source of Cd, and automobile emissions and the use of lead oxide batteries constitute the major sources of Pb. In the urban zone, soils around the wood processing mill showed elevated concentrations of Cu, Cr, Zn, and Ni, while soils around automobile mechanic works and motor parks showed elevated levels of Pb. Elevated Cd concentrations were observed in soils under the following land uses: urban motor park, playground, welding and fabrication sheds, and metallic scrap dump. The contamination/pollution index of metals in the soil follows the order: Ni > Cd > Cr > Zn > Cu > Pb. The multiple pollution index of metals at different sites were greater than 1, indicating that these soils fit into “slight pollution” to “excessive pollution” ranges with significant contributions from Cr, Zn, Cd, Ni, and Cu.