Ancient genomes show social and reproductive behavior of early Upper Paleolithic foragers.

Present-day hunter-gatherers (HGs) live in multilevel social groups essential to sustain a population structure characterized by limited levels of within-band relatedness and inbreeding. When these wider social networks evolved among HGs is unknown. To investigate whether the contemporary HG strategy was already present in the Upper Paleolithic, we used complete genome sequences from Sunghir, a site dated to ~34,000 years before the present, containing multiple anatomically modern human individuals. We show that individuals at Sunghir derive from a population of small effective size, with limited kinship and levels of inbreeding similar to HG populations. Our findings suggest that Upper Paleolithic social organization was similar to that of living HGs, with limited relatedness within residential groups embedded in a larger mating network.

Performative Rituals for Conception and Childbirth in England, 900-1500.

This study proposes that performative rituals-that is, verbal and physical acts that reiterate prior uses-enabled medieval women and men to negotiate the dangers and difficulties of conception and childbirth. It analyzes the rituals implicated in charms, prayers, amulets, and prayer rolls and traces the circulation of such rituals within medieval English society. Manuscript records from the Anglo-Saxon period to the late Middle Ages offer evidence of the interaction of oral and written means of communicating these rituals. Certain rituals were long-lived, though variants were introduced over time that reflected changing religious attitudes and the involvement of various interested parties, including local healers, doctors, and medical practitioners, as well as monks, friars, and users of vernacular remedy books. Although many of those who recommended or provided assistance through performative rituals were males, the practices often devolved upon women themselves, and their female companions or attendants.

Reproductive seasonality of Geophagus steindachneri Eigenmann & Hildebrand, 1922 (Perciformes: Cichlidae) in a tropical mountain river

Reproductive seasonality in tropical freshwater fishes is strongly influenced by rainfall. In lowlands, floods spill laterally to floodplains and fishes usually breed during the flooding season. In mountain rivers, floods are sudden and flush out aquatic organisms. Fishes in mountain rivers usually breed during dry seasons, what has been hypothesized as a strategy to reduce mortality due to strong floods. If that is the case, mouth-brooding fishes should suffer less from strong floods and should have more prolonged breeding seasons in mountain rivers. Here we investigated the breeding activity of a mouth-brooding cichlid (Geophagus steindachneri) in a mountain river in Colombia using three kinds of evidence: monthly variation of gonad weight, macroscopic and histological observations of the gonads, and occurrence of mouth-brooding females. Analysis was made on adults captured monthly throughout a year. The results indicate that G. steindachneri breeds during the dry season in the mountain river studied. Female mouth brooding was related with a halt in the maturation of their ovaries. Other factors than the flushing-out effect of floods on offspring may be determining dry-season breeding of fishes in tropical mountain rivers.

La estacionalidad reproductiva de los peces tropicales de agua dulce esta influida por los patrones de lluvia. En tierras bajas, las aguas se expanden hacia el plano de inundación y los peces generalmente se reproducen en aguas altas. En ríos de montaña las inundaciones son repentinas y arrastran a los organismos acuáticos. Los peces de ríos de montaña usualmente muestran que se reproducen durante las temporadas secas, posiblemente como estrategia para reducir la mortalidad producto de las inundaciones repentinas. Si esta hipótesis es cierta, los peces que realizan incubación bucal estarían menos afectados por las inundaciones repentinas y tendrían una temporada reproductiva más prolongada en los ríos de montaña. En este trabajos estudiamos la temporada reproductiva de un cíclido con incubación bucal (Geophagus steindachneri) en un río de montaña en Colombia, usando tres tipos de evidencia: la variación mensual del peso gonadal, observaciones macroscópicas e histológicas de las gónadas y la frecuencia de las hembras incubando. Los análisis se realizaron en adultos capturados mensualmente durante un año. Nuestros resultados indican que la temporada reproductiva de G. steindachneri en este río de montaña ocurre en la época seca. Se observó una pausa en el desarrollo ovárico durante la incubación bucal. Otros factores, diferentes al arrastre producido por las inundaciones, deben estar determinando la reproducción durante la temporada seca de los peces en los ríos de montaña.

Effects of parental reproductive behavior on offspring sex ratio in a pre-industrial western Mediterranean population (La Alpujarra, 1900-1950, SE Spain).

The reproductive behavior of parents of La Alpujarra (Spain) favorable to male offspring during the first half of the 20th century has been studied is this paper. The family size increased as daughters accumulated because mothers had more pregnancies in order to have higher male offspring, and the reproductive rhythm increased (birth interval decreased) when the first deliveries were only daughters. Although male mortality was higher than female in children older than one year, this reproductive behavior did not determine sex reversal of mortality in babies of between one month and one year, contrary to other developing populations.

Eusociality in history.

For more than 100,000 years, H. sapiens lived as foragers, in small family groups with low reproductive variance. A minority of men were able to father children by two or three women; and a majority of men and women were able to breed. But after the origin of farming around 10,000 years ago, reproductive variance increased. In civilizations which began in Mesopotamia, Egypt, India, and China, and then moved on to Greece and Rome, kings collected thousands of women, whose children were supported and guarded by thousands of eunuchs. Just a few hundred years ago, that trend reversed. Obligate sterility ended, and reproductive variance declined. For H. sapiens, as for other organisms, eusociality seems to be an effect of ecological constraints. Civilizations rose up in lake and river valleys, hemmed in by mountains and deserts. Egalitarianism became an option after empty habitats opened up.

Sexual selection under parental choice: evidence from sixteen historical societies.

Asymmetrical fitness benefits between parents and offspring result in the ideal spouse not being the ideal in-law. This enables parents to attempt to control the mating behavior of their children, and when they succeed, parental choice becomes a primary sexual selection force. A number of studies indicate that parental choice is dominant in contemporary pre-industrial societies. This paper presents evidence from the historical record which indicates that parental choice was also dominant during the later stages of human evolution. More specifically, 40 variables have been coded for a sample of 16 historical societies. Consistent with the model of parental choice, it is found that mating is controlled by parents, male parents exercise more control over marriage arrangements than females, and more control is exercised over female than male offspring. Finally, the specific qualities that parents desire in an in-law and offspring desire in a spouse have also been identified. The implications of these findings are discussed.

Intergenerational transmission of reproductive behavior during the demographic transition.

New evidence from the Utah Population Database (UPDP) reveals that at the onset of the fertility transition, reproductive behavior was transmitted across generations - between women and their mothers, as well as between women and their husbands' family of origin. Age at marriage, age at last birth, and the number of children ever born are positively correlated in the data, most strongly among first-born daughters and among cohorts born later in the fertility transition. Intergenerational ties, including the presence of mothers and mothers-in-law, influenced the hazard of progressing to a next birth. The findings suggest that the practice of parity-dependent marital fertility control and inter-birth spacing behavior derived, in part, from the previous generation and that the potential for mothers and mothers-in-law to help in the rearing of children encouraged higher marital fertility.

Migrants and the diffusion of low marital fertility in Belgium.

Although the diffusion of fertility behavior between different social strata in historical communities has received considerable attention in recent studies, the relationship between the diffusion of fertility behavior and the diffusion of people (migration) during the nineteenth century remains largely underexplored. Evidence from population registers compiled in the Historical Database of the Liège Region, covering the period of 1812 to 1900, reveals that migrant couples in Sart, Belgium, from 1850 to 1874 and from 1875 to 1899 had a reduced risk of conception. The incorporation of geographical mobility, as well as the migrant status of both husbands and wives, into this fertility research sheds light not only on the spread of ideas and behaviors but also on the possible reasons why the ideas and behaviors of immigrants might have been similar to, or different from, those of a native-born population.

Reproductive behavior during the pre-transitional period: evidence from rural Bologna.

A longitudinal, micro-level study of the effect of socioeconomic transformations on fertility mechanisms in the rural hinterland of Bologna between 1818 and 1900 (the beginning of the demographic transition) demonstrates that the premature death of a last-born child reduces the interval between two consecutive childbirths. Thus does it confirm the importance of breast-feeding in determining birth spacing. Women living in complex sharecropping households experienced a significantly higher risk of childbirth than did women in families headed by daily wage earners. In addition, the reproductive behavior of sharecroppers seemed to be substantially invariant to short-term ºuctuations in prices, whereas the laborers' group experienced a negative price effect. Both descriptive and multivariate analyses indicate a slight and gradual decrease in fertility levels during the period in question.

The effect of child support enforcement on abortion in the United States.

OBJECTIVES: This project aims to answer a critically important question of public policy: Does effective child support enforcement lead to a change in the incidence of abortion across the United States? METHODS: Using state-level data collected from 1978­2003 from a variety of sources, we employ fixed effects regression analysis to examine whether financial security as measured by five types of child support enforcement effectiveness impacts abortion outcomes. RESULTS: We find that child support enforcement effectiveness decreases the incidence of abortion as measured by the abortion rate, but not the abortion ratio. CONCLUSIONS: Income transfer policies such as child support enforcement can affect certain fertility outcomes such as abortion rates across the states.

Should we get married? The effect of parents' marriage on out-of-wedlock children.

Using a representative sample of children all born to unwed parents drawn from the Fragile Families and Child Wellbeing Study and a potential outcome approach to account for self-selection into marriage, we investigate whether marriage after childbearing has a causal effect on early child development. Comparing children with similar background characteristics and parental mate-selection patterns who differ only in terms of whether their parents marry after childbirth, we find that marriage after childbirth significantly increases a child's early cognitive performance but there is no evidence that it affects child asthma risk or behavioral outcomes.

Policy experiment in Russia: cash-for-babies and fertility change.

Population decline in modern day Russia is alarmingly steep: Russia loses approximately 750 thousand people each year. To combat population decline, the Russian government instituted aggressive pro-natalist policies. The paper evaluates the capacity of new policies to change women's reproductive behavior using a socio-institutionalist theoretical framework, which analyzes the gendered interaction between the states, the labor market, and family. The paper arrives to a disappointing conclusion that while efforts to improve fertility are quite aggressive, new policies do not challenge gendered hierarchies neither in public nor in private spheres, which will further depress fertility rates of Russian women.

Yearning, learning, and conceding: reasons men and women change their childbearing intentions.

People's childbearing intentions change over the course of their reproductive lives. These changes have been conceptualized as occurring in response to the realization that an individual is unlikely to achieve his or her intended fertility, because of constraints such as the "biological clock" or lack of a partner. In this article, we find that changes to child-bearing plans are influenced by a much wider range of factors than this. People change their plans in response to the wishes of their partners, in response to social norms, as the result of repartnering, and as the result of learning about the costs and benefits of parenthood; there are also differences between the factors that influence men's and women's decision-making. In a departure from existing studies in this area, we use a flexible analytical framework that enables us to analyze increases in planned fertility separately from decreases. This allows us to uncover several complexities of the decision-making process that would otherwise be hidden, and leads us to conclude that the determinants of increases in planned fertility are not simply equal and opposite to the determinants of decreases.

The association of television and radio with reproductive behavior.

This note analyzes the association between media exposure and reproductive behavior in 48 developing countries. A summary of part of a more extensive Demographic and Health Surveys report, it shows strong connections between media exposure and the use of modern contraception, the number of children desired, and recent fertility. Television viewing is particularly important; it is assumed to expose viewers to aspects of modern life that compete with traditional attitudes toward the family and is associated with greater use of modern contraceptive methods, with a desire for fewer children, and with lower fertility. These relationships are particularly noteworthy because the data measure only the frequency of media exposure with no information about its content.

East Asian childbearing patterns and policy developments.

Childbearing behavior in East Asian countries has changed rapidly during the past half century from an average of five to seven children per family, to replacement-level fertility, and subsequently to unprecedentedly low levels, the lowest in the world. This article analyzes fertility trends in Hong Kong, Japan, singapore, south Korea, and Taiwan using cohort fertility data and methods, then examines social and economic causes of the childbearing trends, and surveys policies pursued to reverse the fertility trends. Postponement of childbearing started in the 1970s with continuously fewer delayed births being "recuperated," which resulted in ultra-low fertility. A rapid expansion of education and employment among women in a patriarchal environment has generated a stark dilemma for women who would like to combine childbearing with a career. Policy responses have been slow, with a more serious attempt to address issues in recent years. Thus far public and private institutions are not devoting sufficient attention to generating broad social change supportive of parenting.

Marching toward reproductive justice: coalitional (re) framing of the March for Women's Lives.

This article examines how coalition frames develop and what happens to that frame after the formal coalition ends. To that end, I analyze the frame shift around the 2004 March for Women's Lives (March). The March initially focused on established ideas of reproductive rights around which the four national mainstream co-sponsors previously organized. However, after a newer reproductive justice organization joined the coalition, material and organizing reflected a shift in framing to reproductive justice. How did this change happen? What are the impacts of this event for the women's movement? Through document analysis and interviews, I trace the negotiations that facilitated this framing shift. I argue that this new coalition frame translated into positive lasting changes in organizing for women's reproductive health even as the coalition dissolved and some of the tensions within the larger women's movement remain.

The impact of maternal birth month on reproductive performance: controlling for socio-demographic confounders.

Based on a 1900 census sample of 34,166 post-reproductive females (> or =45 years), the birth month effect was put to the test, for both lifetime fertility as well as child survival, controlling for maternal birth cohort (1826-1835, 1836-1845, 1846-1855), Duncan's SEI, urbanity, nativity, literacy and marital duration. Testing for potential cohort effects did not indicate a temporal trend in fertility by maternal birth month (seasonal Mann-Kendall test, p=0.578), while a minute increase in offspring survival was detected (p<0.001, Sen's estimator of slope=0.02, 95% CI=0.02 to 0.03). Further analyses of the maternal birth month effect on child survival were therefore seized. For lifetime fertility, ANOVA results indicated that maternal birth month was a major predictor for total offspring count (F11, 33606=1809.0, p<0.001), accounting for 37.2% of the total variability. In addition to main effects, a statistically significant interaction effect was observed (F538, 33606=2.2, p<0.001), with a corresponding effect size of eta2=0.40. Planned contrasts revealed that birth-month-specific differences in fertility achieved statistical significance (F11, 31798=1712.9, p<0.001), while post-hoc multiple comparisons for literacy and nativity displayed an inverse relationship with fertility, which meets demographic expectations. Controlling for all factors of interest, models of cohort-specific offspring counts (independent ANOVAs for 1826-1835: F157, 3467=26.3, p<0.001; 1836-1845: F182, 10299=75.5, p<0.001; 1846-1855: F199, 19859=137.9, p<0.001) indicated that women born in the first half of the year (particularly, January, February, April and May) achieved above-average parity, while those born in the latter half (namely, July, October, November and December) displayed markedly lower fertility averages. These monthly disparities are in line with previous observations and appear to be linked to seasonal optimal ripening of the oocyte or seasonal preovulatory over-ripeness ovopathy (Jongbloet, 1992).

Advances in development reverse fertility declines.

During the twentieth century, the global population has gone through unprecedented increases in economic and social development that coincided with substantial declines in human fertility and population growth rates. The negative association of fertility with economic and social development has therefore become one of the most solidly established and generally accepted empirical regularities in the social sciences. As a result of this close connection between development and fertility decline, more than half of the global population now lives in regions with below-replacement fertility (less than 2.1 children per woman). In many highly developed countries, the trend towards low fertility has also been deemed irreversible. Rapid population ageing, and in some cases the prospect of significant population decline, have therefore become a central socioeconomic concern and policy challenge. Here we show, using new cross-sectional and longitudinal analyses of the total fertility rate and the human development index (HDI), a fundamental change in the well-established negative relationship between fertility and development as the global population entered the twenty-first century. Although development continues to promote fertility decline at low and medium HDI levels, our analyses show that at advanced HDI levels, further development can reverse the declining trend in fertility. The previously negative development-fertility relationship has become J-shaped, with the HDI being positively associated with fertility among highly developed countries. This reversal of fertility decline as a result of continued economic and social development has the potential to slow the rates of population ageing, thereby ameliorating the social and economic problems that have been associated with the emergence and persistence of very low fertility.

Voluntary childlessness in marriage and family textbooks, 1950-2000.

We perform a content analysis of twenty marriage and family textbooks published between 1950 and 2000 to study how the voluntarily childless are presented in undergraduate courses. Throughout the time period studied, independence, pursuit of a career, and romance were prominent themes in the representation of voluntary childlessness. Other themes emerged specific to each decade - the 1950s portrayed parenthood as a challenge, while the 1990s concentrated on alleviating negative stereotypes of the voluntarily childless.