Investment by maternal grandmother buffers children against the impacts of adverse early life experiences.

Exogenous shocks during sensitive periods of development can have long-lasting effects on adult phenotypes including behavior, survival and reproduction. Cooperative breeding, such as grandparental care in humans and some other mammal species, is believed to have evolved partly in order to cope with challenging environments. Nevertheless, studies addressing whether grandparental investment can buffer the development of grandchildren from multiple adversities early in life are few and have provided mixed results, perhaps owing to difficulties drawing causal inferences from non-experimental data. Using population-based data of English and Welsh adolescents (sample size ranging from 817 to 1197), we examined whether grandparental investment reduces emotional and behavioral problems in children resulting from facing multiple adverse early life experiences (AELEs), by employing instrumental variable regression in a Bayesian structural equation modeling framework to better justify causal interpretations of the results. When children had faced multiple AELEs, the investment of maternal grandmothers reduced, but could not fully erase, their emotional and behavioral problems. No such result was observed in the case of the investment of other grandparent types. These findings indicate that in adverse environmental conditions the investment of maternal grandmothers can improve child wellbeing.

Matrilateral bias of grandparental investment in grandchildren persists despite the grandchildren's adverse early life experiences.

Evolutionary theory predicts a downward flow of investment from older to younger generations, representing individual efforts to maximize inclusive fitness. Maternal grandparents and maternal grandmothers (MGMs) in particular consistently show the highest levels of investment (e.g. time, care and resources) in their grandchildren. Grandparental investment overall may depend on social and environmental conditions that affect the development of children and modify the benefits and costs of investment. Currently, the responses of grandparents to adverse early life experiences (AELEs) in their grandchildren are assessed from a perspective of increased investment to meet increased need. Here, we formulate an alternative prediction that AELEs may be associated with reduced grandparental investment, as they can reduce the reproductive value of the grandchildren. Moreover, we predicted that paternal grandparents react more strongly to AELEs compared to maternal grandparents because maternal kin should expend extra effort to invest in their descendants. Using population-based survey data for English and Welsh adolescents, we found evidence that the investment of maternal grandparents (MGMs in particular) in their grandchildren was unrelated to the grandchildren's AELEs, while paternal grandparents invested less in grandchildren who had experienced more AELEs. These findings seemed robust to measurement errors in AELEs and confounding due to omitted shared causes.

Transition to Grandparenthood and Subjective Well-Being in Older Europeans: A Within-Person Investigation Using Longitudinal Data.

The transition to grandparenthood, that is the birth of the first grandchild, is often assumed to increase the subjective well-being of older adults; however, prior studies are scarce and have provided mixed results. Investigation of the associations between grandparenthood and subjective well-being, measured by self-rated life satisfaction, quality of life scores, and depressive symptoms, used the longitudinal Survey of Health, Ageing and Retirement in Europe from 13 countries, including follow-up waves between 2006 and 2015 (n = 64,940 person-observations from 38,456 unique persons of whom 18,207 had two or more measurement times). Both between-person and within-person (or fixed-effect) regression models were executed, where between-person associations represent results across individuals, that is, between grandparents and non-grandparents; within-person associations represent an individual's variation over time, that is, they consider whether the transition to grandparenthood increases or decreases subjective well-being. According to the between-person models, both grandmothers and grandfathers reported higher rate of life satisfaction and quality of life than non-grandparents. Moreover, grandmothers reported fewer depressive symptoms than women without grandchildren. The within-person models indicated that entry into grandmotherhood was associated with both improved quality of life scores and improved life satisfaction. These findings are discussed with reference to inclusive fitness theory, parental investment theory, and the grandmother hypothesis.

Grandparental childcare, health and well-being in Europe: A within-individual investigation of longitudinal data.

Previous studies suggest grandparental childcare is associated with improved health and well-being of grandparents but limited information on the causal nature of this association exists. Here, we use the longitudinal Survey of Health, Ageing and Retirement in Europe (SHARE) of people aged 50 and above across 11 countries including follow-up waves between 2004 and 2015 (n = 41,713 person-observations from 24,787 unique persons of whom 11,102 had two or more measurement times). Between-person and within-person (or fixed-effect) regressions were applied, where between-person models show associations across participants and within-person models focus on each participant's variation over time. Health and well-being were measured according to self-rated health, difficulties with activities of daily living (ADLs), depressive symptoms, life satisfaction and meaning of life scores. Across all analyses, childcare assistance provided by older adults to their adult children, was associated with increased health and well-being of grandparents. However, these associations were almost completely due to between-person differences and did not hold in within-person analyses that compared the same participants over time. Fewer ADL limitations for grandparents who provided childcare assistance was the only association that remained in the within-individual analyses. These findings suggest that there might be only limited causal association between grandchild care and grandparental well-being and that it may be specific to physical rather than cognitive factors. The results are discussed with regard to evolutionary psychology assumptions of altruistic behavior and positive health outcomes for the helper.

Cross-cultural evidence does not support universal acceleration of puberty in father-absent households.

Father absence in early life has been shown to be associated with accelerated reproductive development in girls. Evolutionary social scientists have proposed several adaptive hypotheses for this finding. Though there is variation in the detail of these hypotheses, they all assume that family environment in early life influences the development of life-history strategy, and, broadly, that early reproductive development is an adaptive response to father absence. Empirical evidence to support these hypotheses, however, has been derived from WEIRD (Western, Educated, Industrialized, Rich and Democratic) populations. Data from a much broader range of human societies are necessary in order to properly test adaptive hypotheses. Here, we review the empirical literature on father absence and puberty in both sexes, focusing on recent studies that have tested this association beyond the WEIRD world. We find that relationships between father absence and age at puberty are more varied in contexts beyond WEIRD societies, and when relationships beyond the father-daughter dyad are considered. This has implications for our understanding of how early-life environment is linked to life-history strategies, and for our understanding of pathways to adult health outcomes, given that early reproductive development may be linked to negative health outcomes in later life This article is part of the theme issue 'Developing differences: early-life effects and evolutionary medicine'.

Do grandparents influence parents' decision to vaccinate their children? A systematic review.

The global reduction in childhood infectious diseases since the 1960s is primarily due to the success of extensive worldwide immunisation campaigns. However, the universal vaccination coverage program appears to have lost momentum in the wake of negative, unfounded claims about the safety of vaccines. While parents of the 21st century have little first-hand knowledge of devastating childhood diseases, grandparents are more likely to remember family and community members who were afflicted. In the current age of vaccine hesitancy and science scepticism, where research-informed arguments are not always persuasive, grandparents, through their experience of the diseases, may positively influence paediatric vaccine uptake. This paper reviews the literature investigating potential direct or indirect influences of grandparents on parents' decisions to vaccinate their children. A database search using the keywords immunisation, vaccination, children and grandparents resulted in 1988 articles. Titles were screened for relevance and seventy-seven results were retained. After the abstracts were read, only five articles that either explored paediatric vaccines, factors promoting and/or inhibiting paediatric vaccine use and decision-making strategies were reviewed. One paper located through Google Scholar, which failed to show up on database searches, was also retained for a total of six papers. While none of the six papers set out to explore the impact of grandparents on vaccine uptake, they found that grandparents were involved to varying degrees in paediatric vaccine uptake within young families. The research clearly showing that grandparents, and older people more generally, promote vaccination uptake is not currently available. The dearth of literature shows the need for research exploring the perceived and real influences of grandparents on childhood vaccination. This will establish whether grandparents' memory and knowledge of preventable childhood infectious diseases could be harnessed as a public health measure to counteract the current, ill-informed, negative attention on paediatric vaccines.

The impact of maternal nausea and vomiting in pregnancy on expectant fathers: findings from the Australian Fathers' Study.

INTRODUCTION: Nausea and vomiting in pregnancy (NVP) are common. Whilst the impact on pregnant women has been well documented, there is less data on the impact on partners. This study evaluated awareness and impact of maternal NVP on expectant fathers. METHODS: Observational study of 300 expectant fathers. Institutional ethics approval and consent were obtained. Fathers were recruited from antenatal clinics and community settings. Researchers administered demographic, attitudinal and the Hospital Anxiety and Depression scale questionnaires during the third trimester. Expectant fathers were asked if their partner experienced NVP. If aware, they were asked to comment upon the impact on their lives. RESULTS: Participants were similar in demographics to those of the wider Australian community of expectant fathers. Most fathers were aware whether their partner experienced NVP (82%). Of these fathers, 20% reported no NVP, and 30%, 37% and 13% men reported maternal NVP was mild, moderate and severe, respectively. There was no correlation between paternal depression and maternal NVP, but a significant association was found between moderate and severe maternal NVP and paternal anxiety. In qualitative comments, five themes emerged: disruption on work, feelings of frustration and helplessness, concern over depression in their partner, concern for the developing baby and a sense of being manipulated in the third trimester of pregnancy. DISCUSSION: Most expectant fathers are aware of NVP in their partner. Moderate and severe maternal NVP are associated with significantly higher symptoms of paternal anxiety.

A prospective study of associations among helping, health, and longevity.

How does helping behavior contribute to the health and the longevity of older helpers? From an evolutionary perspective, the ultimate cause may be rooted in ancestral parenting and grandparenting. These activities may have generalized to a neural and hormonal caregiving system that also enabled prosocial behavior beyond the family. From a psychological perspective, helping others may be associated with healthy aging, which, in turn, contributes to longevity as a proximate cause. Yet little is known about the extent to which mediating factors such as the health benefits of helping behaviors translate into enhanced longevity, particularly in regard to grandparenting. To fill this gap, we conducted mediation analyses (structural equation models) to examine whether grandparenting and supporting others in the social network contributed directly or indirectly (through better health 5-6 years later) to the longevity of older helpers. We drew on longitudinal data from the Berlin Aging Study (N = 516), in which older adults in Berlin, Germany, were interviewed at baseline (1990-1993, mean age at entry = 85 years) and continuously followed up until 2009. Results suggest that the associations of both grandparenting and supporting others with enhanced longevity are mediated by better prospective health (indirect effect). The effect of helping was not fully mediated, however-helping was also directly associated with increased longevity independently of the health indicators measured. The results were robust against effects of the helper's preexisting health status and sociodemographic characteristics of participants, their children, and grandchildren. We conclude that better prospective health contributes to the link between helping and longevity, but does not fully account for it. Other potential contributing mechanisms remain to be identified. As populations age across the globe, identifying mechanisms that foster health in old age can help to highlight potential targets for public health interventions.

Mother-infant cultural group selection.

Richerson et al. argue that "cultural group selection plays an essential role in explaining human cooperation." We believe that cooperation came first, making culture and thus cultural group selection possible. Cooperation and culture began - and begins - in mother-infant interaction.

The evolved psychological mechanisms of fertility motivation: hunting for causation in a sea of correlation.

Cultural, ecological, familial and physiological factors consistently influence fertility behaviours, however, the proximate psychological mechanisms underlying fertility decisions in humans are poorly understood. Understanding the psychological mechanisms underlying human fertility may illuminate the final processes by which some of these known predictors have their influence. To date, research into the psychological mechanisms underlying fertility has been fragmented. Aspects of reproductive psychology have been examined by researchers in a range of fields, but the findings have not been systematically integrated in one review. We provide such a review, examining current theories and research on psychological mechanisms of fertility. We examine the methods and populations used in the research, as well as the disciplines and theoretical perspectives from which the work has come. Much of the work that has been done to date is methodologically limited to examining correlations between ecological, social and economic factors and fertility. We propose, and support with examples, the use of experimental methods to differentiate causal factors from correlates. We also discuss weaknesses in the experimental research, including limited work with non-WEIRD (western, educated, industrialized, rich and democratic) populations.

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.

Somatoform disorders in patients with chronic pain.

OBJECTIVE: To assess the frequency and characteristics of somatoform disorders in patients with chronic pain. METHOD: The study took place in the psychiatric outpatient clinic of a rehabilitation hospital. Participants were interviewed using the World Health Organization Somatoform Disorders Schedule (WHO-SDS) version 2.0. Thirty new and 30 current attendees to the clinic were interviewed following referral by pain medicine specialists. RESULTS: Somatoform disorders were commonly co-morbid with chronic pain in the study population. Persistent somatoform pain disorder (PSPD) was the commonest somatoform disorder. There was a significant difference between women and men suffering from somatic autonomic dysfunction (SAD). CONCLUSIONS: The findings of this study confirm that somatoform disorders are common co-morbid diagnoses in patients with chronic pain. Combining psychological treatments with medication, appropriate physical treatments and attending to social issues, may indeed improve the well-being of such patients.

Patterns of physical and psychological development in future teenage mothers.

BACKGROUND AND OBJECTIVES: Teenage childbearing may have childhood origins and can be viewed as the outcome of a coherent reproductive strategy associated with early environmental conditions. Life-history theory would predict that where futures are uncertain fitness can be maximized through diverting effort from somatic development into reproduction. Even before the childbearing years, future teenage mothers differ from their peers both physically and psychologically, indicating early calibration to key ecological factors. Cohort data have not been deliberately collected to test life-history hypotheses within Western populations. Nonetheless, existing data sets can be used to pursue relevant patterns using socioeconomic variables as indices of relevant ecologies. METHODOLOGY: We examined the physical and psychological development of 599 young women from the National Child Development Study who became mothers before age 20, compared to 599 socioeconomically matched controls. RESULTS: Future young mothers were lighter than controls at birth and shorter at age 7. They had earlier menarche and accelerated breast development, earlier cessation of growth and shorter adult stature. Future young mothers had poorer emotional and behavioural adjustment than controls at age 7 and especially 11, and by age 16, idealized younger ages for marriage and parenthood than did the controls. CONCLUSIONS AND IMPLICATIONS: The developmental patterns we observed are consistent with the idea that early childbearing is a component of an accelerated reproductive strategy that is induced by early-life conditions. We discuss the implications for the kinds of interventions likely to affect the rate of teenage childbearing.

Early-life conditions and age at first pregnancy in British women.

There is growing evidence that the reproductive schedules of female mammals can be affected by conditions experienced during early development, with low parental investment leading to accelerated life-history strategies in the offspring. In humans, the relationships between early-life conditions and timing of puberty are well studied, but much less attention has been paid to reproductive behaviour. Here, we investigate associations between early-life conditions and age at first pregnancy (AFP) in a large, longitudinally studied cohort of British women (n = 4553). Low birthweight for gestational age, short duration of breastfeeding, separation from mother in childhood, frequent family residential moves and lack of paternal involvement are all independently associated with earlier first pregnancy. Apart from that of birthweight, the effects are robust to adjustment for family socioeconomic position (SEP) and the cohort member's mother's age at her birth. The association between childhood SEP and AFP is partially mediated by early-life conditions, and the association between early-life conditions and AFP is partially mediated by emotional and behavioural problems in childhood. The overall relationship between early-life adversities and AFP appears to be approximately additive.

Grandparental investment: past, present, and future.

What motivates grandparents to their altruism? We review answers from evolutionary theory, sociology, and economics. Sometimes in direct conflict with each other, these accounts of grandparental investment exist side-by-side, with little or no theoretical integration. They all account for some of the data, and none account for all of it. We call for a more comprehensive theoretical framework of grandparental investment that addresses its proximate and ultimate causes, and its variability due to lineage, values, norms, institutions (e.g., inheritance laws), and social welfare regimes. This framework needs to take into account that the demographic shift to low fecundity and mortality in economically developed countries has profoundly altered basic parameters of grandparental investment. We then turn to the possible impact of grandparental acts of altruism, and examine whether benefits of grandparental care in industrialized societies may manifest in terms of less tangible dimensions, such as the grandchildren's cognitive and verbal ability, mental health, and well-being. Although grandparents in industrialized societies continue to invest substantial amounts of time and money in their grandchildren, we find a paucity of studies investigating the influence that this investment has on grandchildren in low-risk family contexts. Under circumstances of duress - for example, teenage pregnancy or maternal depression - there is converging evidence that grandparents can provide support that helps to safeguard their children and grandchildren against adverse risks. We conclude by discussing the role that grandparents could play in what has been referred to as Europe's demographic suicide.

Birthweight and paternal involvement predict early reproduction in British women: evidence from the National Child Development Study.

There is considerable interest in the mechanisms maintaining early reproduction in the most socioeconomically disadvantaged groups in developed countries. Previous research has suggested that differential exposure to early-life factors such as low birthweight and lack of paternal involvement during childhood may be relevant. Here, we used longitudinal data on the female cohort members from the UK National Child Development Study (n = 3,014-4,482 depending upon variables analyzed) to investigate predictors of early reproduction. Our main outcome measures were having a child by age 20, and stating at age 16 an intended age of reproduction of 20 years or lower. Low paternal involvement during childhood was associated with increased likelihood of early reproduction (O.R. 1.79-2.25) and increased likelihood of early intended reproduction (O.R. 1.38-2.50). Low birthweight for gestational age also increased the odds of early reproduction (O.R. for each additional s.d. 0.88) and early intended reproduction (O.R. for each additional s.d. 0.81). Intended early reproduction strongly predicted actual early reproduction (O.R. 5.39, 95% CI 3.71-7.83). The results suggest that early-life factors such as low birthweight for gestational age, and low paternal involvement during childhood, may affect women's reproductive development, leading to earlier target and achieved ages for reproduction. Differential exposure to these factors may be part of the reason that early fertility persists in socioeconomically disadvantaged groups. We discuss our results with respect to the kinds of interventions likely to affect the rate of teen pregnancy.

Reproductive development and parental investment during pregnancy: moderating influence of mother's early environment.

The association between a woman's age at menarche and the birth weight of her children is highly variable across human populations. Life history theory proposes that a woman's early environment may moderate this association and thus account for some of the variation between populations. According to one life history theory model, for individuals who develop in a childhood environment of high local mortality rates (experienced subjectively as psychosocial stress), it can be adaptive to mature earlier, have more offspring during their reproductive lifetime, and reduce investment in each offspring. In an environment of low psychosocial stress, however, it may be adaptive to mature later, have fewer offspring, and invest more in each. In this study, birth weight and proportionate birth weight (neonate's birth weight as a percentage of its mother's prepregnancy weight) were used as measures of parental investment during pregnancy. In a sample of 580 first-time mothers, we tested the hypothesis that the psychosocial stress experienced as a child would moderate the association between age at menarche and investment during pregnancy. We found that earlier menarche in those women who experienced stressful life events before 15 years of age was associated with a lower birth weight and proportionate birth weight. Conversely, in those who reported no childhood stressors, earlier menarche was associated with increased birth weight and proportionate birth weight. Our data suggest that the moderating influence of the childhood psychosocial environment on the association between age at menarche and parental investment throughout gestation operates in a dose-dependent manner.

Grandparental investment: The influence of reproductive timing and family size.

The influence that grandparents have on the life history traits of their descendants has been studied extensively. However, no attention has been paid to the potential influence a grandparent's own reproductive history has on the investment they make in their grandchildren. We use data from 658 Swiss grandchildren and 591 of their grandparents to investigate whether grandparents' reproductive scheduling and family size influence the amount of investment grandparents make in a focal grandchild (shared contacts, occasions to meet, activities, discussions, interests, and important roles the grandparent plays). Grandparents who were younger when they had their first child had more children and grandchildren; this relationship strengthened after controlling for grandparental age, sex, lineage, and education (all P < 0.001). Generally, having more children or grandchildren was associated with reduced levels of grandparental investment. After adjustment for a wide range of factors known to influence investment, having more children or grandchildren and having a first child or grandchild at a younger age were associated with reduced investment in 14 of 24 analyses (all P < 0.09). The association between reproductive scheduling and investment was partially mediated by the grandparent's family size. Interestingly, these relationships were only present in data reported from the grandchild's point of view, not the grandparent's. This analysis provides preliminary evidence that grandparents' reproductive strategies have consequences for the amount of investment they make in their grandchildren. These results are examined in terms of the trade-offs between current and future reproduction and offspring quality and quantity.

Gross placental structure in a low-risk population of singleton, term, first-born infants.

Suboptimal fetal growth has been associated with an increased risk of adult disease, which may be exacerbated by an increased placental weight-to-fetal weight ratio. Placental weight is a summary measure of placental growth and development throughout pregnancy. However, measures of placental structure, including the chorionic disk surface area and thickness and eccentricity of the umbilical cord insertion, have been shown to account for additional variance in birth weight beyond that explained by placental weight. Little is known of the variability of these placental parameters in low-risk populations; their association with maternal, pregnancy, and neonatal characteristics; and the agreement between manual and digital measures. This study used manual and digital image analysis techniques to examine gross placental anatomy in 513 low-risk, singleton, term, first-born infants. Parametric methods compared groups and examined relationships among variables. Maternal birth weight, prepregnancy weight, and body mass index were associated with increased placental and birth weight (all P < 0.005), but only maternal birth weight was associated with increased placental surface area (P < 0.0005) and thickness (P = 0.005). Smoking during pregnancy reduced birth weight and increased the eccentricity of umbilical cord insertion (P = 0.012 and 0.034, respectively). The variability in these placental parameters was consistently lower than that reported in the literature, and correlations between digital and manual measurements were reasonable (r = .87-.71). Detailed analyses of gross placental structure can provide biologically relevant information regarding placental growth and development and, potentially, their consequences.

The association between depressive personality and treatment outcome for depression following a group cognitive-behavioral intervention.

The present study investigated the association of depressive personality traits to treatment outcome for depression. One hundred and nineteen patients with a primary diagnosis of major depression were divided into high- and low-depressive personality groups, and depression symptomatology was assessed pre- and postparticipation in a standardized group cognitive-behavioral intervention. Analyses revealed poorer pre-state and end-state functioning for the high-depressive personality group. However, rate of improvement pre- to posttreatment was comparable between the two groups. Subsequent multiple regression analyses revealed that when controlling for pretreatment depression severity, depressive personality was not a predictor of depression treatment outcome. Within the methodological parameters of the current study, depressive personality traits were not associated with a poorer response to cognitive-behavioral treatment for depression.