R Sear
Datos Biográficos
| ID | 9603 |
|---|---|
| NOMBRE | R Sear |
| NOMBRES | R |
| APELLIDO | Sear |
| FIRMA | SEAR R |
| AFILIACIONES | London School of Hygiene & Tropical Medicine |
| ORCID | 0000-0002-4315-0223 |
| VERIFICADO | Sí |
| TOTAL DE OBRAS | 68 |
| TOTAL DE CITAS | 498 |
| TOTAL COMO AUTOR | 68 |
| TOTAL COMO EDITOR | 0 |
| PRIMER AÑO DE PUBLICACIÓN | 1997 |
| AÑO MÁS RECIENTE DE PUBLICACIÓN | 2026 |
| ÍNDICE H | 13 |
Childcare in Transition
Highlights This study uses novel data on multiple childcare types from both kin and nonkin in two culturally similar communities with varying market integration. It tests the hypothesis that market integration is associated with reduced kin support. Who provides support and the type of support vary by level of market integration. Market integration disrupts childcare support from paternal but not maternal kin. Distant kin and nonkin substitute fo…
Religious parents receive more alloparental aid in rural Bangladesh
Researchers have long speculated about the evolutionary benefits of religiosity. One explanation for the evolution of religious ritual is that rituals signal commitment to co-religionists. As a major domain of prosocial behaviour, alloparental care – or care directed at children by non-parents – is a plausible benefit of religious signalling. The religious alloparenting hypothesis posits that parents who signal religious commitment receive greate…
Children's Caregiving and Growth in Northwestern Tanzania
Receiving care from individuals other than one's mother (i.e., allomothering) is a universal aspect of raising children, but whether and how such care impacts children's health remains subject to debate. Existing studies in low‐income societies largely use broad proxies for caregiving behaviors rather than measuring childcare activities, which may mask variation in allomothering and, thus, its impact on children's health. Using data collected to …
Versatility, value and limitations of using health and demographic surveillance system data for secondary analyses
Household structure in Ghana
BACKGROUNDThe nuclear convergence hypothesis proposes that development and urbanisation lead to increasing proportions of nuclear families.We explore this hypothesis in Ghana by charting household living arrangements as captured in censuses and surveys. OBJECTIVETo classify household structure in Ghana and track trends to test whether households converge towards nucleation during processes of development and urbanisation. METHODSWe employ two met…
Nuclearization of maternal support networks in the UK and the US during the Covid-19 pandemic
The social isolation resulting from governments' responses to the COVID-19 pandemic likely limited support available to mothers. Evidence suggests tasks like childcare and domestic work fell disproportionately on mothers during the pandemic, with consequences for their wellbeing. We explore how the pandemic affected emotional and practical support available to mothers between March and August 2020 and whether changes in support are associated wit…
Religious women receive more allomaternal support from non-partner kin in two low-fertility countries
Cost structures and socioecological conditions impact the fitness outcomes of human alloparental care in agent-based model simulations
Religious Involvement Is Associated With Higher Fertility and Lower Maternal Investment, but More Alloparental Support Among Gambian Mothers
OBJECTIVES: Human childrearing is cooperative, with women often able to achieve relatively high fertility through help from many individuals. Previous work has documented tremendous socioecological variation in who supports women in childrearing, but less is known about the intracultural correlates of variation in allomaternal support. In the highly religious, high-fertility setting of The Gambia, we studied whether religious mothers have more ch…
Transitions to adulthood in men and women in rural Malawi in the 21st century using sequence analysis
BACKGROUNDMany sub-Saharan African countries have large populations of young people, and these cohorts have the potential to bring significant change.Understanding the changing lives of young people is important for ensuring individuals experience healthy and successful transitions to adulthood and for understanding how best to ensure they realise their full potential, for themselves and their communities. METHODSThis analysis used detailed, pros…
How age and sex affect treatment outcomes for children with severe malnutrition
Age and sex influence the risk of childhood wasting. We aimed to determine if wasting treatment outcomes differ by age and sex in children under 5 years, enroled in therapeutic and supplementary feeding programmes. Utilising data from stage 1 of the ComPAS trial, we used logistic regression to assess the association between age, sex and wasting treatment outcomes (recovery, death, default, non-response, and transfer), modelling the likelihood of …
The future is unstable”
While studies conducted at the beginning of the pandemic found that fertility intentions became more anti-natal, we found little overall change in fertility intentions in January 2021. Our findings of small pro-natal and anti-natal changes in fertility intentions align with emerging UK birth rate data for 2021, which show minimal change in the total fertility rate in response to the pandemic
Life history trade-offs associated with exposure to low maternal capital are different in sons compared to daughters
Background: Environmental exposures in early life explain variability in many physiological and behavioural traits in adulthood. Recently, we showed that exposure to a composite marker of low maternal capital explained the clustering of adverse behavioural and physical traits in adult daughters in a Brazilian birth cohort. These associations were strongly mediated by whether or not the daughter had reproduced by the age of 18 years. Using evoluti…
Fertility and faith
Disentangling the relationships between religion and fertility
In this issue of Religion, Brain & Behavior, scholars from multiple disciplines offer comments on Jenkins ' Fertility and Faith (Jenkins, 2020).The debate, and Jenkins' response to the commentaries, contribute to moving scholarship forward in an often-neglected area in the scientific study of religion.The book tackles an extensive literature, synthesizing work on several topics: drivers of secularization, drivers of fertility decline, the relatio…
Nutritional status and adult mortality in a mid-20 th century Gambian population
Measures of nutritional status are often used as markers of health, at both individual- and population-level. Different measures of nutritional status–such as height or weight, for example,–may have different associations with health outcomes because they reflect both current nutritional status and the accumulation of past health experiences, but the weighting of past and present experiences differs between different measures. Here, we present an…
Life-history tradeoffs in a historical population (1896–1939) undergoing rapid fertility decline
Evolutionary demographers often invoke tradeoffs between reproduction and survival to explain reductions in fertility during demographic transitions. The evidence for such tradeoffs in humans has been mixed, partly because tradeoffs may be masked by individual differences in quality or access to resources. Unmasking tradeoffs despite such phenotypic correlations requires sophisticated statistical analyses that account for endogeneity among variab…
The impact of market integration on arranged marriages in Matlab, Bangladesh
Success in marriage markets has lasting impacts on women's wellbeing. By arranging marriages, parents exert financial and social powers to influence spouse characteristics and ensure optimal marriages. While arranging marriages is a major focus of parental investment, marriage decisions are also a source of conflict between parents and daughters in which parents often have more power. The process of market integration may alter parental investmen…
Mother's Partnership Status and Allomothering Networks in the United Kingdom and United States
In high-income, low-fertility (HILF) settings, the mother's partner is a key provider of childcare. However, it is not clear how mothers without partners draw on other sources of support to raise children. This paper reports the findings from a survey of 1532 women in the United Kingdom and the United States, in which women described who provided childcare for a focal child and how frequently they did so. We use multivariate Bayesian regression m…
Historical Context Changes Pathways of Parental Influence on Reproduction
Several studies have found that parental absences in childhood are associated with individuals' reproductive strategies later in life. However, these associations vary across populations and the reasons for this heterogeneity remain debated. In this paper, we examine the diversity of parental associations in three ways. First, we test whether different kinds of parental availability in childhood and adolescence are associated with women's and men…
Years of Population Studies
A diamond anniversary special issueThe celebration of anniversaries is a long-standing, widespread, and popular custom, connecting us to the cycle of life and prompting reflections on who we have become.Celebrations are often linked to demographic events or transitions, such as births and weddings or, in the case of royalty, events such as transition to the throne.As 2021 draws to a close, Population Studies: A Journal of Demography completes its…
Children of the (gender) revolution
Gender equity theories of fertility broadly predict that the lowest fertility in high-income settings will be seen in women facing a 'dual burden' of both paid and unpaid labour responsibilities, but that fertility will increase when male partners share domestic labour. Here we provide a critique of some gender equity theories of fertility in demography, and restate the hypothesis in terms of complementarity between partners. Further, we suggest …
Demography and the rise, apparent fall, and resurgence of eugenics
Demography was heavily involved in the eugenics movement of the early twentieth century but, along with most other social science disciplines, largely rejected eugenic thinking in the decades after the Second World War. Eugenic ideology never entirely deserted academia, however, and in the twenty-first century, it is re-emerging into mainstream academic discussion. This paper aims, first, to provide a reminder of demography's early links with eug…
Boys are more likely to be undernourished than girls
We are family
Sarah Hrdy’s new book proposes a new hypothesis for the evolution of the human mind. She extends her previous work on cooperative breeding to argue that the very flexible form of cooperative childrearing that our species engages in has been an important force during the evolution of what makes us so different, and so successful, compared to other primates. Specifically, it is this strategy which has resulted in the evolution of our remarkably ext…
How Much Does Family Matter? Cooperative Breeding and the Demographic Transition
In this paper we review the empirical evidence that women receive help from family members in raising children, by drawing together published research which has explicitly investigated the impact of kin on child well-being. It is clear from this review that in both pre- and post-demographic transition societies family matters: the presence of certain relatives improves child survival and well-being, though which relatives matter differs between p…
The effects of kin on child mortality in rural gambia
We analyzed data that were collected continuously between 1950 and 1974 from a rural area of the Gambia to determine the effects of kin on child mortality. Multilevel event-history models were used to demonstrate that having a living mother, maternal grandmother, or elder sisters had a significant positive effect on the survival probabilities of children, whereas having a living father, paternal grandmother, grandfather, or elder brothers had no …
Domestication Alone Does Not Lead to Inequality
We present empirical measures of wealth inequality and its intergenerational transmission among four horticulturalist populations. Wealth is construed broadly as embodied somatic and neural capital, including body size, fertility and cultural knowledge, material capital such as land and household wealth, and relational capital in the form of coalitional support and field labor. Wealth inequality is moderate for most forms of wealth, and intergene…
Kin and Child Survival in Rural Malawi
Does the kin orientation of a British woman's social network influence her entry into motherhood
The influence of family and friends on an individualâ s fertility has long been an important topic within demography. Researchers who focus on social network effects and evolutionary demography have shown a renewed interest in this issue in recent years. Ho
Children of the (gender) revolution
Gender equity theories of fertility broadly predict that the lowest fertility in high-income settings will be seen in women facing a 'dual burden' of both paid and unpaid labour responsibilities, but that fertility will increase when male partners share domestic labour. Here we provide a critique of some gender equity theories of fertility in demography, and restate the hypothesis in terms of complementarity between partners. Further, we suggest …
Grandparental help in Indonesia is directed preferentially towards needier descendants
Trade-Offs in Children's Time Allocation
Embodied capital theory (ECT) argues that socioeconomic "modernization" leads to high-cost, high-return parental investments in education, in turn incentivizing demographic transitions to low fertility. However, few studies have directly investigated the proposed opportunity costs of schooling in contemporary developing populations undergoing socioeconomic change. We present a study of children's time use in two communities in Mwanza, Tanzania, r…
Modernizing Evolutionary Anthropology
Height and reproductive success
Earning their keep? Fostering, children's education, and work in north-western Tanzania
Fostering, raising children that are not oneâ s biological children, is common in many societies worldwide. Despite predicted lower investment in nonbiological offspring, numerous studies report no obvious well-being penalty for fostered children. Building
Support for new mothers and fertility in the United Kingdom
Low fertility across Europe highlights the need to understand reproductive decisions in high-income countries better. Availability of support may be one factor influencing reproductive decisions, though within high-income countries availability varies between environments, including socio-economic environments. We test whether receiving higher levels of support, from different sources (informal and formal) and of different types (practical and em…
Does Wealth Increase Parental Investment Biases in Child Education
Why fertility declines is still a matter of intense debate. One theory proposes that fertility decline may be partly driven by shifts in parental investment strategies: couples reduce family size as demographic and economic changes cause investment in the quality of children to become more important than investment in the quantity of children. A key driver for this change is a shift from a subsistence-based to a skills-based economy, in which edu…
The Reproductive Ecology of Industrial Societies, Part II
Studies of the association between wealth and fertility in industrial populations have a rich history in the evolutionary literature, and they have been used to argue both for and against a behavioral ecological approach to explaining human variability. We consider that there are strong arguments in favor of measuring fertility (and proxies thereof) in industrial populations, not least because of the wide availability of large-scale secondary dat…
Life after death
Both life history theory and demographic transition theory predict that fertility responds to changes in mortality, but there have been relatively few tests which identify links between mortality perceptions and fertility preferences at the individual level. This paper provides an individual-level investigation of the relationship between mortality and fertility, by testing whether mortality priming results in an increase in fertility preferences…
Supportive families versus support from families
Support from families can reduce costs of reproduction and may therefore be associated with higher fertility for men and women. Family supportiveness, however, varies both between families â some families are more supportive than others â and within famili
Evolutionary contributions to the study of human fertility
Demography, lacking an overarching theoretical framework of its own, has drawn on theories in many other social sciences to inform its analyses. The aim of this paper is to bring to the demographic community's attention research in the evolutionary sciences on fertility, and to demonstrate that evolutionary theory can be another useful tool in the demographer's toolkit. I first dispel some myths which impede the incorporation of evolutionary theo…
The Reproductive Ecology of Industrial Societies, Part I
Is fertility relevant to evolutionary analyses conducted in modern industrial societies? This question has been the subject of a highly contentious debate, beginning in the late 1980s and continuing to this day. Researchers in both evolutionary and social sciences have argued that the measurement of fitness-related traits (e.g., fertility) offers little insight into evolutionary processes, on the grounds that modern industrial environments differ…
Does grandparental help mediate the relationship between kin presence and fertility
Previous research suggests that kin availability may be correlated with reproductive outcomes, but it is not clear that a causal relationship underlies these findings. Further, there is substantial variation in how kin availability is measured
Father Absence and Reproduction-Related Outcomes in Malaysia, a Transitional Fertility Population
Father absence is consistently associated with children's reproductive outcomes in industrialized countries. It has been suggested that father absence acts as a cue to particular environmental conditions that influence life history strategies. Much less is known, however, about the effects of father absence on such outcomes in lower-income countries. Using data from the 1988 Malaysian Family Life Survey (n = 567), we tested the effect of father a…
Interdisciplinary perspectives on grandparental investment
Why do grandparents invest so heavily in their grandchildren and what impact does this investment have on families? A multitude of factors influence the roles grandparents play in their families. Here, we present an interdisciplinary perspective of grandparenting incorporating theory and research from evolutionary biology, sociology and economics. Discriminative grandparental solicitude, biological relatedness and the impact of resource availabil…
Synthesis in the human evolutionary behavioural sciences
Over the last three decades, the application of evolutionary theory to the human sciences has shown remarkable growth. This growth has also been characterised by a ?splitting? process, with the emergence of distinct sub-disciplines, most notably: Human Behavioural Ecology (HBE), Evolutionary Psychology (EP) and studies of Cultural Evolution (CE). Multiple applications of evolutionary ideas to the human sciences are undoubtedly a good thing, demon…
Fathers favour sons, mothers don't discriminate
Worldwide fertility declines do not rely on stopping at ideal parities
A key demographic hypothesis has been that fertility declines rely on stopping at target parities, but emerging evidence suggests that women frequently reduce fertility without specific numeric targets. To assess the relative importance of these two paths to fertility decline, we develop a novel mixture model to estimate: (1) the proportion of women who stop at a target parity; and (2) mean completed fertility among those who do not. Applied to D…
Life-history tradeoffs in a historical population (1896–1939) undergoing rapid fertility decline
Evolutionary demographers often invoke tradeoffs between reproduction and survival to explain reductions in fertility during demographic transitions. The evidence for such tradeoffs in humans has been mixed, partly because tradeoffs may be masked by individual differences in quality or access to resources. Unmasking tradeoffs despite such phenotypic correlations requires sophisticated statistical analyses that account for endogeneity among variab…
Birth Interval and the Sex of Children in a Traditional African Population
Birth interval is a major determinant of rates of fertility, and is also a measure of parental investment in a child. In this paper the length of the birth interval in a traditional African population is analysed by sex of children. Birth intervals after the birth of a boy were significantly longer than after the birth of a girl, indicating higher parental investment in boys. However, in women of high parity, this differential disappeared. Birth …
Reproductive Decisions by Gabbra Pastoralists in the Face of Demographic Risks
The effects of kin on child mortality in rural gambia
We analyzed data that were collected continuously between 1950 and 1974 from a rural area of the Gambia to determine the effects of kin on child mortality. Multilevel event-history models were used to demonstrate that having a living mother, maternal grandmother, or elder sisters had a significant positive effect on the survival probabilities of children, whereas having a living father, paternal grandmother, grandfather, or elder brothers had no …
The effects of kin on female fertility in rural Gambia
Size-dependent reproductive success in Gambian men
Size is an important component of life history analysis, as it is both a determinant and an outcome of life history decisions. Here, we present an investigation of the relationships between two components of size (height and weight) and life history outcomes for men in a rural Gambian population. This population suffered seasonal food shortages and high disease loads, and lacked access to medical care or contraception. We find that there is no re…
Height and reproductive success
Synthesis in the human evolutionary behavioural sciences
Over the last three decades, the application of evolutionary theory to the human sciences has shown remarkable growth. This growth has also been characterised by a ?splitting? process, with the emergence of distinct sub-disciplines, most notably: Human Behavioural Ecology (HBE), Evolutionary Psychology (EP) and studies of Cultural Evolution (CE). Multiple applications of evolutionary ideas to the human sciences are undoubtedly a good thing, demon…
The impact of reproduction on gambian women
Life history theory predicts that where resources are limited, investment in reproduction will cause a decline in body condition and ultimately may lower survival rates. We investigate the relationship between reproduction and mortality in women in rural Gambia. We use a number of different measures of reproductive investment: the timing of reproduction, intensity of reproduction, and cumulative reproductive investment (parity). Though giving bir…
Who keeps children alive? A review of the effects of kin on child survival
Life after death
Both life history theory and demographic transition theory predict that fertility responds to changes in mortality, but there have been relatively few tests which identify links between mortality perceptions and fertility preferences at the individual level. This paper provides an individual-level investigation of the relationship between mortality and fertility, by testing whether mortality priming results in an increase in fertility preferences…
Kin and Child Survival in Rural Malawi
Introduction to special issue on “Trade‐Offs in Female Life Histories
Does Wealth Increase Parental Investment Biases in Child Education
Why fertility declines is still a matter of intense debate. One theory proposes that fertility decline may be partly driven by shifts in parental investment strategies: couples reduce family size as demographic and economic changes cause investment in the quality of children to become more important than investment in the quantity of children. A key driver for this change is a shift from a subsistence-based to a skills-based economy, in which edu…
Domestication Alone Does Not Lead to Inequality
We present empirical measures of wealth inequality and its intergenerational transmission among four horticulturalist populations. Wealth is construed broadly as embodied somatic and neural capital, including body size, fertility and cultural knowledge, material capital such as land and household wealth, and relational capital in the form of coalitional support and field labor. Wealth inequality is moderate for most forms of wealth, and intergene…
Evolution and human behavioural diversity
Human beings persist in an extraordinary range of ecological settings, in the process exhibiting enormous behavioural diversity, both within and between populations. People vary in their social, mating and parental behaviour and have diverse and elaborate beliefs, traditions, norms and institutions. The aim of this theme issue is to ask whether, and how, evolutionary theory can help us to understand this diversity. In this introductory article, w…
How Much Does Family Matter? Cooperative Breeding and the Demographic Transition
In this paper we review the empirical evidence that women receive help from family members in raising children, by drawing together published research which has explicitly investigated the impact of kin on child well-being. It is clear from this review that in both pre- and post-demographic transition societies family matters: the presence of certain relatives improves child survival and well-being, though which relatives matter differs between p…
The Peacock’s Tale
Author(s): Blumstein, Daniel T.; Atran, Scott; Field, Scott; Hochberg, Michael; Johnson, Dominic; Sagarin, Raphael; Sosis, Richard; Thayer, Bradley; Fearon, James; Morin, Olivier; Sear, Rebecca; Geller, Armando | Abstract: This is a Focus Article with Commentaries that was published on the Social Evolution Forum
Kin influences on fertility in Thailand
Human behavioral ecology
Human behavioral ecology (HBE) is the study of human behavior from an adaptive perspective. It focuses in particular on how human behavior varies with ecological context. Although HBE is a thriving research area, there has not been a major review published in a journal for over a decade, and much has changed in that time. Here, we describe the main features of HBE as a paradigm and review HBE research published since the millennium. We find that …
Does the kin orientation of a British woman's social network influence her entry into motherhood
The influence of family and friends on an individualâ s fertility has long been an important topic within demography. Researchers who focus on social network effects and evolutionary demography have shown a renewed interest in this issue in recent years. Ho
Fostering relations
Kinship fostering is generally preferred to non-kin fostering by policy makers in the U.S. and elsewhere. Researchers and policy makers alike tend to provide several proximate reasons for why this may be, generally neglecting an ultimate evolutionary framework. However, kin selection theory predicts that in the absence of genetically related parents, care from kin will result in the most similar life history outcomes. In low-fertility settings, p…
Father Absence and Reproduction-Related Outcomes in Malaysia, a Transitional Fertility Population
Father absence is consistently associated with children's reproductive outcomes in industrialized countries. It has been suggested that father absence acts as a cue to particular environmental conditions that influence life history strategies. Much less is known, however, about the effects of father absence on such outcomes in lower-income countries. Using data from the 1988 Malaysian Family Life Survey (n = 567), we tested the effect of father a…
Evolutionary Demography
Evolutionary contributions to the study of human fertility
Demography, lacking an overarching theoretical framework of its own, has drawn on theories in many other social sciences to inform its analyses. The aim of this paper is to bring to the demographic community's attention research in the evolutionary sciences on fertility, and to demonstrate that evolutionary theory can be another useful tool in the demographer's toolkit. I first dispel some myths which impede the incorporation of evolutionary theo…
Grandparental help in Indonesia is directed preferentially towards needier descendants
Sociology (51 obras) · Demography (43 obras) · Demographic Trends and Gender Preferences (38 obras) · Biology (35 obras) · Psychology (34 obras) · Population (33 obras) · Family Dynamics and Relationships (27 obras) · Fertility (27 obras) · Evolutionary Psychology and Human Behavior (23 obras) · Medicine (20 obras)