Marital Dissolution and Child Educational Outcomes in San Borja, Bolivia

Purpose: 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. Methods: Using interview data from over 400 women in San Borja, Bolivia, discrete-time event history analyses and random effects regression analyses are conducted to examine predictors of marital dissolution, separated by remarriage status, and child educational outcomes. Results: Male income is inversely associated with women’s risk of ‘divorce and remarriage’, while 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. Conclusions: In conclusion, there are different predictors of divorce depending on whether the woman goes on to remarry, suggesting that male income may be a better predictor of a serial monogamy strategy, while female income predicts marital dissolution only. These results suggest that women who are relatively autonomous because of greater income may not benefit from remarriage

Variation in Wealth and Educational Drivers of Fertility Decline Across 45 Countries

Fertility decline in human populations is an inherent evolutionary puzzle with major demographic, socio-cultural and evolutionary consequences. The individual level predictors of fertility decline are numerous, but the way these effects vary by country and how they are causally mediated by other factors has received relatively little attention. Here we take a multilevel approach to compare similarities and differences in the primary predictors of contemporary fertility declines—wealth and education—across 45 countries in Africa, Asia, Central and South America, the Caribbean, and the Middle East using Demographic and Health Survey (DHS) data collected from 2003 to 2015. We use multilevel models to understand variation in the slopes of these predictors on fertility, and structural equation models to examine the causal pathways by which they take their effects, focusing on four mediating variables: local mortality and birth rates, women’s work status, and contraceptive use. We find that associations between wealth and fertility differ substantially across populations, while associations between education and fertility are consistently negative. The mediators also vary: community-level birth rates and women’s contraceptive use are important mediators between education, wealth and the number of children born across a wide variety of countries, but community-level mortality rates and women’s work status are not. We discuss our results in the context of different causal pathways that reflect cultural and biological evolutionary dynamics as simultaneous and interacting drivers of fertility decline

The Association of Sex Ratio on Suicide Rates in United States Counties: An Exploration of Mechanisms

Researchers have long puzzled over suicidal behavior. In this paper, we posit that when people are unable to attract mates given unfavorable sex ratios, suicide rates increase. Sex ratio, the proportion of males in a population, is linked to a variety of behaviors, including marriage stability, violence, depression, and infidelity. We test whether suicide rates are associated with county-level sex ratios utilizing data from 1999 to 2018, controlling for a variety of factors known to be associated with suicide risk. We find that sex ratio is associated with suicide rates, where a greater proportion of males in a county (age 35–74) is associated with an increased rate of suicide for these males. Mediation analyses show that these effects are mediated by male marriage rates. Counter to predictions, male-biased sex ratios also tend to be associated with increased female suicide rates for women aged 35 to 74, and this effect is mediated by the unmarried sex ratio (i.e., when there are more unmarried men compared to unmarried women in a county, there is increased female suicide). Overall, these results suggest that male-biased sex ratios are associated with suicide rates for both men and women, but the mediators vary

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. OBJECTIVE We attempt to identify whether different measures of kin availability influence how kin affect reproductive outcomes and whether the effect of kin on reproductive outcomes is driven by the help that they provide. METHODS Using data from the Indonesia Family Life Survey (1993, 1997, 2000, 2007), we compare the survival of parents and parents-in-law, their co-residence, geographic proximity, contact frequency, and helping behavior in predicting fertility outcomes, and test a hypothesized causal pathway linking kin availability to reproduction via helping behavior. RESULTS We find different results if we operationalize parental availability as survival or co-residence, suggesting that these measures cannot be used interchangeably. Receiving help from parents or parents-in-law has a positive effect on progression to birth when women have fewer than three living children. Path analyses show that geographic proximity is associated with contact frequency, which in turn influences helping behavior. Kin help has a positive effect on progression to giving birth for all parental categories, but the effects are strongest for mothers-in-law. CONCLUSION In Indonesia, kin availability has a positive effect on fertility only when kin provide help, suggesting that there is a causal relationship between kin availability and fertility which is mediated via the provision of help

Does grandparental help mediate the relationship between kin presence and fertility?

Background: 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. Objective: We attempt to identify whether different measures of kin availability influence how kin affect reproductive outcomes and whether the effect of kin on reproductive outcomes is driven by the help that they provide. Methods: Using data from the Indonesia Family Life Survey (1993, 1997, 2000, 2007), we compare the survival of parents and parents-in-law, their co-residence, geographic proximity, contact frequency, and helping behavior in predicting fertility outcomes, and test a hypothesized causal pathway linking kin availability to reproduction via helping behavior. Results: We find different results if we operationalize parental availability as survival or co-residence, suggesting that these measures cannot be used interchangeably. Receiving help from parents or parents-in-law has a positive effect on progression to birth when women have fewer than three living children. Path analyses show that geographic proximity is associated with contact frequency, which in turn influences helping behavior. Kin help has a positive effect on progression to giving birth for all parental categories, but the effects are strongest for mothers-in-law. Conclusions: In Indonesia, kin availability has a positive effect on fertility only when kin provide help, suggesting that there is a causal relationship between kin availability and fertility which is mediated via the provision of help

Fertility Intentions and Outcomes in Indonesia: Evolutionary Perspectives on Sexual Conflict

Differential fertility preferences for men and women may provide insights into human sexual conflict. We explore whether pairbonded couples have different preferences for future offspring, which socioecological factors are associated with these preferences, and who achieves their desired fertility over time. We utilise the Indonesia Family Life Survey (IFLS), a longitudinal survey which collected data from 1993 to 2015, to compare desired future fertility for 9655 couples and follow couples who had divergent preferences. The majority of couples (64.8%) want the same number of future offspring. In 20.7% of couples, husbands want more future offspring than their wives, while the reverse occurs in 14.5% of couples. Living in villages with the husband\u27s or the wife\u27s parent(s) is associated with having divergent preferences for future offspring, where there is a higher likelihood that women prefer more offspring than their husbands. When examining fertility outcomes, women, particularly those who marry at older ages, are more likely to achieve their desired preference. Contrary to previous research, we do not find that living near one\u27s natal kin or having increased autonomy increases an individual\u27s likelihood of achieving desired fertility outcomes

Behavioral Ecology of the Family: Harnessing Theory to Better Understand Variation in Human Families

Researchers across the social sciences have long been interested in families. How people make decisions such as who to marry, when to have a baby, how big or small a family to have, or whether to stay with a partner or stray are questions that continue to interest economists, sociologists, demographers, and anthropologists. Human families vary across the globe; different cultures have different marriage practices, different ideas about who raises children, and even different notions of what a family is. Human behavioral ecology is a branch of anthropology that is particularly interested in cultural variation of family systems and how these differences impact upon the people that inhabit them; the children, parents, grandparents. It draws on evolutionary theory to direct research and generate testable hypotheses to uncover how different ecologies, including social contexts, can explain diversity in families. In this Special Issue on the behavioral ecology of the family, we have collated a selection of papers that showcase just how useful this framework is for understanding cultural variation in families, which we hope will convince other social scientists interested in family research to draw upon evolutionary and ecological insight in their own work

Life-History Factors Influence Teenagers’ Suicidal Ideation: A Model Selection Analysis of the Canadian National Longitudinal Survey of Children and Youth

Suicidality is an important contributor to disease burden worldwide. We examine the developmental and environmental correlates of reported suicidal ideation at age 15 and develop a new evolutionary model of suicidality based on life history trade-offs and hypothesized accompanying modulations of cognition. Data were derived from the National Longitudinal Survey of Children and Youth (Statistics Canada) which collected information on children’s social, emotional, and behavioral development in eight cycles between 1994 and 2009. We take a model selection approach to understand thoughts of suicide at age 15 (N ≈ 1,700). The most highly ranked models include social support, early life psychosocial stressors, prenatal stress, and mortality cues. Those reporting consistent early life stress had 2.66 greater odds of reporting thoughts of suicide at age 15 than those who reported no childhood stress. Social support of the primary caregiver, neighborhood cohesion, nonkin social support of the adolescent, and the number of social support sources are all associated with suicidal thoughts, where greater neighborhood cohesion and social support sources are associated with a reduction in experiencing suicidal thoughts. Mother’s prenatal smoking throughout pregnancy is associated with a 1.5 greater odds of suicidal thoughts for adolescents compared to children whose mother’s reported not smoking during pregnancy. We discuss these findings in light of evolutionary models of suicidality. This study identifies both positive and negative associations on suicidal thoughts at age 15 and considers these in light of adaptive response models of human development. Findings are relevant for mental health policy

Sexual Initiation Among Canadian Youth: A Model Comparison Approach of Evolutionary Hypotheses Shows Greatest Support for Extrinsic Mortality Cues, Intergenerational Conflict, and Early Life Psychosocial Stressors

Early life factors are associated with the timing of reproductive events in adolescence, but a variety of hypotheses (such as psychosocial acceleration theory, paternal investment theory, extrinsic mortality, internal prediction, and intergenerational conflict) propose different explanations for why this may occur. To compare between these theories, we use the National Longitudinal Survey of Children and Youth, an extensive, longitudinal survey of Canadian male and female youth (aged 14-15 in last wave) to identify variables that uniquely support these different models (n≈1200). We identify the best predictors of sexual initiation for each hypothesis and then use a model selection procedure to determine which set of variables has the most support. Results show that variables representing extrinsic mortality cues, intergenerational conflict, early life psychosocial stressors, and prenatal factors are included in the top models, while variables representing social support and unpredictability are represented in some of the top models. Variables representing the paternal investment theory were not included in any of the top models, suggesting limited support for this hypothesis. These results support many of the hypotheses that have been previously presented in the literature, suggesting that timing of sexual initiation may have multiple causal pathways

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 absence on daughters' age at menarche, first marriage, and first birth; parity progression rates; and desired completed family size in Malaysia, a country undergoing an economic and fertility transition. Father absence during later childhood (ages 8 to 15), although not during earlier childhood, was associated with earlier progressions to first marriage and first birth, after controlling for other confounders. Father absence does not affect age at menarche, desired family size, or progression from first to second birth. The patterns found in this transitional population partly mirror those in developed societies, where father absence accelerates reproductive events. There is, however, a notable contrast between the acceleration in menarche for father-absent girls consistently found in developed societies and the lack of any association in our findings. The mechanisms through which father absence affects reproduction may differ in different ecological contexts. In lower-income contexts, direct paternal investment or influence may be of more importance in determining reproductive behavior than whether fathers act as a cue to environmental conditions