Childhood predictors of self reported chronic fatigue syndrome/myalgic encephalomyelitis in adults: national birth cohort study

Objective To study childhood risk factors for chronic fatigue syndrome in adult life.Design Examination of data from the 1970 British birth cohort.Participants 16 567 babies born 5-11 April 1970, followed up at 5, 10, 16, and 29-30 years.Main outcome measures Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) identified by self report at age 30 years. Data from childhood from questionnaires given to parents and teachers. Maternal mental health assessed with the malaise inventory.Results 93 (0.8%, 95% confidence interval 0.7 to 1.0) of 11 261 participants reported ever having CFS/ME, and 48 (0.4%, 0.3 to 0.6) had the condition currently. Higher risk of CFS/ME was associated with having a limiting longstanding condition in childhood (odds ratio 2.3, 1.4 to 3.9), female sex (2.3, 1.4 to 2.6), and high social class in childhood (2.2, 1.4 to 3.5). Higher levels of exercise in childhood were associated with lower risk (0.5, 0.2 to 0.9). Maternal psychological disorder, psychological problems in childhood, birth weight, birth order, atopy, obesity, school absence, academic ability, and parental illness were not associated with risk of CFS/ME.Conclusions We identified no association between maternal or child psychological distress, academic ability, parental illness, atopy, or birth order and increasing risk of lifetime CFS/ME. Sedentary behaviour increased the risk.     

Grandparental Effects on Fertility Vary by Lineage in the United Kingdom

Grandparental presence is known to correlate with the number of grandchildren born, and this effect may vary according to grandparental sex and lineage. However, existing studies of grandparental effects on fertility mostly concern traditional subsistence societies, while evidence from contemporary developed societies is both scarce and mixed. Here, we explore how grandparents affect the transition to second and subsequent children in the contemporary United Kingdom. The longitudinal Millennium Cohort Study (n = 10,295 families) was used to study the association between grandparental investment and parents’ probability of having a new child within 4.5 years. Results show that contact with paternal grandparents is associated with higher probability of parents having a second child. In contrast, contact with maternal grandparents is associated with lower probability of having a third or subsequent child. Kin may have opposite effects on fertility even in contemporary societies, which may explain the lack of consistent effects of grandparental investment on fertility in previous studies.     

Grandpaternal care and child survival in a pastoralist society in western China

Human parents require significant support to raise multiple, highly dependent offspring. Grandmothers are often highlighted as key allomothers (non-maternal caregivers) and their presence is frequently associated with increased child survivorship, leading some to describe humans as cooperative breeders. Equally well documented is the diversity of human childcare systems, where a wide range of individuals support parents including male kin. However, the role of grandfathers has been less well documented, and they seem to have an inconsistent relationship with child survivorship, dependent on socio-ecological factors. Here, we explore the relationship between grandparental allomothering and child survivorship using demographic and time budget data from a pastoralists community in western China. We find that under-five mortality is negatively associated with grandpaternal, but not grandmaternal, living status. Pastoralists in Maqu have recently transitioned from mobile to half-settled livelihoods in which women are more economically active than males. As a result, women's childcare workloads have decreased, while older men (who are excluded from the household economy) supervise children. Our results suggest that patterns of childcare are flexible and highlight the need to consider social and ecological factors to understand allomothering and child survival.     

Adult socioeconomic,educational, social,and psychological outcomes of childhood obesity: a national birth cohort study

Objectives To assess adult socioeconomic, educational, social, and psychological outcomes of childhood obesity by using nationally representative data.Design 1970 British birth cohort.Participants 16 567 babies born in Great Britain 5-11 April 1970 and followed up at 5, 10, and 29-30 years.Main outcome measures Obesity at age 10 and 30 years. Self reported socioeconomic, educational, psychological, and social outcomes at 30 years. Odds ratios were calculated for the risk of each adult outcome associated with obesity in childhood only, obesity in adulthood only, and persistent child and adult obesity, compared with those obese at neither period.Results Of the 8490 participants with data on body mass index at 10 and 30 years, 4.3% were obese at 10 years and 16.3% at 30 years. Obesity in childhood only was not associated with adult social class, income, years of schooling, educational attainment, relationships, or psychological morbidity in either sex after adjustment for confounding factors. Persistent obesity was not associated with any adverse adult outcomes in men, though it was associated among women with a higher risk of never having been gainfully employed (odds ratio 1.9, 95% confidence interval 1.1 to 3.3) and not having a current partner (2.0, 1.3 to 3.3).Conclusions Obesity limited to childhood has little impact on adult outcomes. Persistent obesity in women is associated with poorer employment and relationship outcomes. Efforts to reduce the socioeconomic and psychosocial burden of obesity in adult life should focus on prevention of the persistence of obesity from childhood into adulthood.     

Family and Fertility: Kin Influence on the Progression to a Second Birth in the British Household Panel Study

Particular features of human female life history, such as short birth intervals and the early cessation of female reproduction (menopause), are argued to be evidence that humans are ‘cooperative breeders’, with a reproductive strategy adapted to conditions where mothers receive substantial assistance in childraising. Evolutionary anthropologists have so far largely focussed on measuring the influence of kin on reproduction in natural fertility populations. Here we look at the effect in a present-day low-fertility population, by analysing whether kin affect parity progression in the British Household Panel Study. Two explanatory variables related to kin influence significantly increase the odds of a female having a second birth: i) having relatives who provide childcare and ii) having a larger number of frequently contacted and emotionally close relatives. Both effects were measured subject to numerous socio-economic controls and appear to be independent of one another. We therefore conclude that kin may influence the progression to a second birth. This influence is possibly due to two proximate mechanisms: kin priming through communication and kin assistance with childcare.     

Premarital childbearing in northwest Kenya: challenging the concept of illegitimacy

A number of African countries, including Kenya, have experienced a marked rise in births among unmarried women. In Western countries, reproduction outside of marriage is assumed to be illegitimate and a social problem. One hypothesis used to explain the increasing incidence of premarital fertility in Africa is a breakdown of traditional social controls by the extended family over the sexual behavior of adolescents. A competing hypothesis suggests that unmarried women use sexual relations to achieve goals such as marriage. Among Turkana pastoralists of northwest Kenya, we find a pattern of premarital birth that fits either hypothesis only loosely. Premarital fertility among the Turkana is both widespread and culturally acceptable, with over 30 per cent of women having at least one child prior to marriage. Although women with premarital births initiate childbearing on average one year earlier than women with only marital births, women's marital status does not influence the length of the interval between first and second births. Marriage among the Turkana is not a social trigger for the onset and continuation of reproduction or a means to legitimate reproduction. Marital status of the parents simply determines the custody of a child. In a premarital birth, the father pays a set fee to the mother's family, and the custody of the child remains permanently with the mother's family. If the parents later marry, the father must purchase custody of the child by another fee at that time. Since the Turkana have experienced few effects of modernization, the existence of such a practice suggests that cultural factors must be taken into account before assessing premarital fertility in Africa as a social problem.     

Reduced birth intervals following the birth of children with long-term illness: evidence supporting a conditional evolved response

Human birth interval length is indicative of the level of parental investment that a child will receive: a short interval following birth means that parental resources must be split with a younger sibling during a period when the older sibling remains highly dependent on their parents. From a life-history theoretical perspective, it is likely that there are evolved mechanisms that serve to maximize fitness depending on context. One context that would be expected to result in short birth intervals, and lowered parental investment, is after a child with low expected fitness is born. Here, data drawn from a longitudinal British birth cohort study were used to test whether birth intervals were shorter following the birth of a child with a long-term health problem. Data on the timing of 4543 births were analysed using discrete-time event history analysis. The results were consistent with the hypothesis: birth intervals were shorter following the birth of a child diagnosed by a medical professional with a severe but non-fatal medical condition. Covariates in the analysis were also significantly associated with birth interval length: births of twins or multiple births, and relationship break-up were associated with significantly longer birth intervals.     

How Grandparents Matter

Low birth rates in developed societies reflect women’s difficulties in combining work and motherhood. While demographic research has focused on the role of formal childcare in easing this dilemma, evolutionary theory points to the importance of kin. The cooperative breeding hypothesis states that the wider kin group has facilitated women’s reproduction during our evolutionary history. This mechanism has been demonstrated in pre-industrial societies, but there is no direct evidence of beneficial effects of kin’s support on parents’ reproduction in modern societies. Using three-generation longitudinal data anchored in a sample of grandparents aged 55 and over in 1992 in the Netherlands, we show that childcare support from grandparents increases the probability that parents have additional children in the next 8 to 10 years. Grandparental childcare provided to a nephew or niece of childless children did not significantly increase the probability that those children started a family. These results suggest that childcare support by grandparents can enhance their children’s reproductive success in modern societies and is an important factor in people’s fertility decisions, along with the availability of formal childcare.     

A synthetic biosocial model of fertility transition: Testing the relative contribution of embodied capital theory,changing cultural norms,and women's labor force participation

This article presents a biosocial model of fertility decline, which integrates ecological‐economic and informational‐cultural hypotheses of fertility transition in a unified theoretical framework. The model is then applied to empirical data collected among 500 women from San Borja, Bolivia, a population undergoing fertility transition. Using a combination of event history analysis, multiple regression, and structural equation modeling, we examine the pathways by which education responds to birth cohort, parental education and network ties, and how age at first birth and total fertility, in turn, respond to birth cohort, social network ties, education, expectations about parental investment, work, and contraceptive use. We find that in addition to secular trends in education, respondent's education is associated with the education of parents, the investment she received from them, and the education of older siblings. Total fertility has dropped over time, partly in response to increased education; moreover, the behavior of other women in a woman's social network predicts both initiation of reproduction and total fertility, while expected parental investment in offspring negatively predicts total fertility. Involvement in paid work that is incompatible with childcare is associated with a later age of first reproduction, but not subsequent fertility. Contraceptive use partially mediates the effect of education and birth cohort on total fertility, but is not a mediator of the effect of social network or expected parental investment on total fertility. Overall, the empirical results provide support for a biosocial model of fertility decline, particularly the embodied capital and cultural pathways. Am J Phys Anthropol 154:322–333, 2014. © 2014 Wiley Periodicals, Inc.     

Birth weight and later socioeconomic disadvantage: evidence from the 1958 British cohort study.

OBJECTIVE--To investigate the relation between birth weight and socioeconomic disadvantage during childhood and adolescence in a birth cohort study. DESIGN--Longitudinal analysis of birth weight in relation to social class, household amenities and overcrowding, and financial difficulties as reported by parents at interview when participants were aged 7, 11, and 16 years; and receipt of unemployment or supplementary benefits as reported by participants at age 23. SUBJECTS--Male participants in the 1958 birth cohort (national child development study) born to parents resident in Great Britain during the week of 3-9 March 1958. Data on birth weight and financial difficulties between birth and 23 years were available for 4321; data on housing conditions and social class at ages 7, 11, and 16 years were available for 3370. MAIN OUTCOME MEASURES--Socioeconomic disadvantage at later ages in men weighing 6 lb (2721g) or under at birth compared with those weighing over 6 lb and between fifths of the distribution of birth weight. RESULTS--Cohort members who weighed 6 lb or under at birth were more likely to experience socioeconomic disadvantage subsequently. Those in lower fifths of the distribution were more likely to experience socioeconomic disadvantage. CONCLUSION--Low birth weight is associated with socioeconomic disadvantage in childhood and adolescence. Studies of the association of indicators of early development and adult disease need to take into account experiences right through from birth to adulthood if they are to elucidate the combination of risks attributable to developmental problems and socioeconomic disadvantage.     

Childcare, height and BMI among female Polish university students, 2005

The aim of this study is to consider whether socio-economic factors are related to the type of childcare and whether the type of childcare, in turn, affects adult stature and BMI. The sample includes 783 female students aged 20-24 (birth cohort of 1981-1985) from the south of Poland. Those whose parents have university education, live in a city and have no siblings attend day-care facilities more frequently than others of the same age, while those who grew up at home under their mothers' care, most frequently live in villages, come from large families and their parents have vocational education. Variables which are associated with being taller include material conditions and the type of childcare received. Women who had attended day-care centres are 2.4cm shorter than girls brought up at home by their mothers. Adult BMI values are influenced by educational level of the mother. The results suggest that mothers who work often do so at the cost of time devoted to the family which influences health and the rate of their children's development.     

The socioeconomic gradient in child health and noncognitive skills: Evidence from the Czech Republic

We investigate the presence of a socioeconomic status (SES) gradient in children’s health and noncognitive skill development, and its evolution with child age using cohort data from the Czech Republic. We show that family SES are positively associated with better child health. These effects start to emerge at age 3 and are persistent for all subsequent ages. We find a modest strengthening of the gradient as the children grow older. Similarly, at the lowest distribution of average family income, children lag in their noncognitive skills. We find evidence that children enter school with substantial differences in noncognitive skill endowments based on family SES. This correlation persists when controlling for poor health at birth, the roles of specific and chronic health problems, housing conditions, and partner characteristics. Maternal health status explains some of the association between family income and child noncognitive skills. We account for the endogeniety of SES and non-linearities in measures.     

Social life factors affecting the mortality, longevity, and birth rate of total Japanese population: effects of rapid industrialization and urbanization

To expand upon the findings that lower mortality was found in Japanese urban areas in contrast to the Western model where in the US and Britain the risk of death was higher in metropolitan areas and conurbations, 22 social life indicators are examined among 46 prefectures in Japan in terms of their effect on age specific mortality, life expectancy, and age adjusted marriage, divorce, and birth rates. The effects of these factors on age adjusted mortality for 8 major working and nonworking male populations, where also analyzed. The 22 social life factors were selected from among 227 indicators in the system of Statistical Indicators on Life. Factor analysis was used to classify the indicators into 8 groups of factors for 1970 and 7 for 1975. Factors 1-3 for both years were rural or urban residence, low income and unemployment, and prefectural age distribution. The 4th for 1970 was home help for the elderly and for 1975, social mobility. The social life indicators were classified form 1 to 8 as rural residence in 1970 and 1975, urban residence, low income, high employment, old age, young age, social mobility, and home help for the elderly which moved from 8th place in 1970 to 1st in 1975. Between 1960-75, rapid urbanization took place with the proportion of farmers, fishermen, and workers declining from 43% in 1960 to 19% in 1975. The results of stepwise regression analysis indicate a positive relationship of urban residence with mortality of men and women except school-aged and middle-aged women, and the working populations, as well as life expectancy at birth for males and females and ages 20 and 40 years for males. Rural residence was positively associated with the male marriage rate, whereas the marriage rate for females was affected by industrialization and urbanization. High employment and social mobility were positively related to the female marriage rate. Low income was positively related to the divorce rate for males and females. Rural residence and high employment were positively related to the birth rate. The birth rate is higher in rural areas. Mortality of professional, engineering, and administrative workers was slightly lower than the total working population, while sales workers, those in farming, fishing, and forestry, and in personal and domestic service had significantly higher mortality. The mortality of the nonworking population was 6-8 times higher than sales, transportation, and communication, and personal and domestic service as well as the total population.     

Predictors of Grandparental Investment Decisions in Contemporary Europe: Biological Relatedness and Beyond

Across human cultures, grandparents make a valued contribution to the health of their families and communities. Moreover, evidence is gathering that grandparents have a positive impact on the development of grandchildren in contemporary industrialized societies. A broad range of factors that influence the likelihood grandparents will invest in their grandchildren has been explored by disciplines as diverse as sociology, economics, psychology and evolutionary biology. To progress toward an encompassing framework, this study will include biological relatedness between grandparents and grandchildren, a factor central to some discipline''s theoretical frameworks (e.g., evolutionary biology), next to a wide range of other factors in an analysis of grandparental investment in contemporary Europe. This study draws on data collected in the Survey of Health, Ageing and Retirement in Europe from 11 European countries that included 22,967 grandparent–child dyads. Grandparents reported biological relatedness, and grandparental investment was measured as the frequency of informal childcare. Biological and non-biological grandparents differed significantly in a variety of individual, familial and area-level characteristics. Furthermore, many other economic, sociological, and psychological factors also influenced grandparental investment. When they were controlled, biological grandparents, relative to non-biological grandparents, were more likely to invest heavily, looking after their grandchildren almost daily or weekly. Paradoxically, however, they were also more likely to invest nothing at all. We discuss the methodological and theoretical implications of these findings across disciplines.     

Caregiving within and beyond the family is associated with lower mortality for the caregiver: A prospective study

Grandparenting has been proposed as an ultimate evolutionary mechanism that has contributed to the increase in human life expectancy (see the grandmother hypothesis). The neural and hormonal system – originally rooted in parenting and thus grandparenting – that is activated in the process of caregiving has been suggested as a potential proximate mechanism that promotes engagement in prosocial behavior towards kin and non-kin alike. Evidence and theory suggest that activating this caregiving system positively impacts health and may reduce the mortality of the helper. Although some studies have found grandparental care to have beneficial effects on grandparents' health outcomes, most studies have focused on the detrimental health consequences of providing custodial care for grandchildren. Little is known about how non-custodial grandparental and other forms of caregiving relate to mortality hazards for the care provider. Using an evolutionary framework, we examined whether caregiving within and beyond the family is related to mortality in older adults. Survival analyses based on data from the Berlin Aging Study revealed that mortality hazards for grandparents who provided non-custodial childcare were 37% lower than for grandparents who did not provide childcare and for non-grandparents. These associations held after controlling for physical health, age, socioeconomic status and various characteristics of the children and grandchildren. Furthermore, the effect of caregiving extended to non-grandparents and to childless older adults who helped beyond their families. Potential ultimate and proximate mechanisms underlying these effects are discussed.     

Marital Dissolution and Child Educational Outcomes in San Borja,Bolivia

Serial monogamy is likely an adaptive mating strategy for women when the expected future fitness gains with a different partner are greater than expected future fitness with one’s current partner. Using interview data from more than 400 women in San Borja, Bolivia, discrete-time event history analyses and random effects regression analyses were conducted to examine predictors of marital dissolution, separated by remarriage status, and child educational outcomes. Male income was found to be inversely associated with women’s risk of “divorce and remarriage,” whereas female income is positively associated with women’s risk of “divorce, but not remarriage.” Children of women who divorce and remarry tend to have significantly lower educational outcomes than children of married parents, but women with higher incomes are able to buffer their children from the negative educational outcomes of divorce and remarriage. Counter to predictions, there is no evidence that women with kin in the community have a significant difference in likelihood of divorce or a buffering effect of child outcomes. In conclusion, predictors of divorce differ depending on whether the woman goes on to remarry, suggesting that male income may be a better predictor of a serial monogamy strategy whereas female income predicts marital dissolution only. Thus, women who are relatively autonomous because of greater income may not benefit from remarriage.     

Is handedness exogenously determined? Counterevidence from South Korea

Establishing whether handedness is exogenously determined can help explain the relationship between handedness and various health and economic outcomes. It can also ensure the use of handedness as an instrument in empirical applications. Using data from the Korean National Health and Nutrition Examination Survey and the National Health and Nutrition Examination Survey in the United States, I investigate the exogeneity of children’s handedness by examining the determinants of mixed-handedness. In the analysis using Korean data, parents’ age, parents’ non-right-handedness, and family income influence the likelihood of children’s mixed-handedness. In the U.S. data analysis, however, none of the child and family characteristics, except being Asian, predict the likelihood of mixed-handedness. These results suggest that mixed-handedness, further handedness cannot be generalized as exogenous and is a race-specific characteristic.     

Parental height differences predict the need for an emergency caesarean section

More than 30% of all pregnancies in the UK require some form of assistance at delivery, with one of the more severe forms of assistance being an emergency Caesarean section (ECS). Previously it has been shown that the likelihood of a delivery via ECS is positively associated with the birth weight and size of the newborn and negatively with maternal height. Paternal height affects skeletal growth and mass of the fetus, and thus might also affect pregnancy outcomes. We hypothesized that the effect of newborn birth weight on the risk of ECS would decrease with increasing maternal height. Similarly, we predicted that there would be an increase in ECS risk as a function of paternal height, but that this effect would be relative to maternal height (i.e., parental height differences). We used data from the Millennium Cohort Study: a large-scale survey (N = 18,819 births) with data on babies born and their parents from the United Kingdom surveyed 9 to 12-months after birth. We found that in primiparous women, both maternal height and parental height differences interacted with birth weight and predicted the likelihood of an ECS. When carrying a heavy newborn, the risk of ECS was more than doubled for short women (46.3%) compared to tall women (21.7%), in agreement with earlier findings. For women of average height carrying a heavy newborn while having a relatively short compared to tall partner reduced the risk by 6.7%. In conclusion, the size of the baby, the height of the mother and parental height differences affect the likelihood of an ECS in primiparous women.     

The effect of paternal investment on female fertility intention in South Korea

Life history theory views reproduction as an outcome of resource allocation. The allocation of resources such as parental investments of time, energy and material resources involves trade-offs between number of offspring and timing of reproduction. Within the framework of mammalian parental investment, the outstanding feature of human reproduction is the high level of paternal care. Although empirical evidence suggests that human paternal investment may have evolved as a reproductive strategy to reduce infant and child mortality rates, the effects of actual paternal investment, including allocating time to child care, on female reproductive decisions have received relatively little attention. We examined the trade-off from two perspectives using a representative sample of married South Korean women aged 20–44 in 2005 (n=977). First, paternal investment in domestic labor, including child care and housework, was expected to be associated with women's preference regarding future reproduction. Second, relative paternal investment was expected to increase women's preference for future reproduction, especially among employed women. We found that increased paternal investment in child care and housework remarkably enhanced women's intention to have a second child, especially among employed women. In addition, although family members provide a low percentage of child care in South Korea, such help is likely to be a useful resource for second childbirth among employed women. Somewhat expectedly, older age and longer time since first birth had negative effects on women's second-child intention. There is growing evidence that, in the lowest fertility societies, paternal investment may be an essential resource for promoting future reproductive behavior of women, especially employed women.     

A demographic dilemma: The Parsis of Karachi

Abstract

Own‐children fertility estimates derived from the Korean censuses of 1966 and 1970 indicate that the total fertility rate fell by more than half a child in the intercensal period, from an estimated 4,837 to 4,257 per thousand. A compositional analysis shows that about one‐fourth of the fall can be attributed to changes in population composition by urban‐rural residence, education, marital status, and parity, and about three‐fourths to changes in age‐specific birth rates cross‐classified by these same characteristics. The own‐children method is used to generate the finely specified birth rates necessary for this analysis, and a decomposition technique used previously by one of the authors is extended to incorporate the unusually large number of compositional variables.