Kermyt G. Anderson

Paternal Care by Genetic Fathers and Stepfathers I: Reports from Albuquerque Men

Abstract We present a biosocial model of human male parental care that allows male parental allocations to be influenced not only by changes in the fitness (welfare) of the recipient offspring, but also by their effects on the mans relationship with the childs mother. The model recognizes four classes of relationships between males and the children they parent: genetic offspring of current mates (combined relationship and parental effort), genetic offspring of previous mates (parental effort solely), step offspring of current mates (relationship effort solely), and stepchildren of previous mates (essentially no expected investment). We test the model using data on parental investments collected from adult males living in Albuquerque, New Mexico, U.S.A. Four measures of paternal investment are examined: the probability that a child attends college (2,191 offspring), the probability that a child who attends college receives money for it ( N = 1,212), current financial expenditures on children ( N = 635), and the amount of time per week that men spend with children ages 5 to 12 years ( N = 2,589). The tests are consistent with a role for relationship effort in parental care: men invest more in the children of their current mates, even when coresidence with offspring is not a confounder.

Paternal Care by Genetic Fathers and Stepfathers II: Reports by Xhosa High School Students

Abstract In this article we present a biosocial model of human male parental care that allows relationship (mating) effort to influence male parental allocations. The model recognizes four classes of relationships between men and the children they parent: genetic offspring of current mates (combined relationship and parental effort), genetic offspring of previous mates (parental effort solely), step offspring of current mates (relationship effort solely), and stepchildren of previous mates (essentially no expected investment). We test the model using data on parental investment collected from 340 Xhosa high school students in Cape Town, South Africa. Six measures of paternal investment are examined: the amount of money men spent on students for school, clothing, and miscellaneous expenditures, respectively, and how often men spent time with children, helped them with their homework, or spoke English with them. The tests provide support for the roles of both parental and relationship effort in influencing parental care: men invest significantly more in their genetic offspring and in the children of their current mates. We also examine several proximate influences on parental care, specifically the age and sex of the child, and the percentage of the childs life the father figure coresided with him or her.

Causes and Consequences of Schooling Outcomes in South Africa: Evidence from Survey Data

This paper provides an overview of evidence on education in South Africa provided by household survey data, with a particular focus on large national surveys such as the 1993 South African Living Standards Survey and the annual October Household Survey. These surveys indicate that racial gaps in schooling persist in South Africa, although they have declined steadily over time. There is essentially no gender gap in schooling, however, with almost identical schooling outcomes for men and women in all racial groups. The racial gap in schooling can be largely attributed to a high rate of grade repetition for Africans, with only small differences in enrollment rates across racial groups. School quality has an important effect on both grade attainment and adult economic outcomes, and is clearly an important component of the racial gap in schooling. Survey data clearly demonstrate a large effect of schooling on earnings beginning in late primary years, with a higher rate of return to schooling for Africans than for whites. Datasets Used October Household Survey (OHS): South Africa, 1995 Schooling outcomes in South Africa

Relatedness and investment in children in South Africa.

Investment in children is examined using a nationally representative sample of 11,211 black (African) households in South Africa. I randomly selected one child from each household in the sample and calculated the average genetic relatedness of the other household members to the focal child. Using multivariate statistical analysis to control for background variables such as age and sex of child, household size, and socioeconomic status, I examine whether the coefficient of relatedness predicts greater household expenditures on food, on health care, and on children’s clothing. I also test whether relatedness is associated with health and schooling outcomes. The results are consistent with an inclusive fitness model: Households invest more in children who are more closely related. Two exceptions were found: in rural areas, genetic relatedness was negatively associated with money spent on food and on health care. Explanations for these results are discussed.

The life histories of American stepfathers in evolutionary perspective.

This paper presents an analysis of the characteristics of men who become stepfathers, and their subsequent fertility patterns and lifetime reproductive success. Because women who already have children are ranked lower in the marriage market than women without children, men who marry women with children (e.g., stepfathers) are likely to have lower rankings in the marriage market as well. Using retrospective fertility and marital histories from the Panel Study of Income Dynamics (PSID), I show that men who become stepfathers have lower levels of education, less income, and are more likely to have been divorced before and to already have children, all characteristics that lower their rankings in the marriage market. Men with one or two stepchildren are just as likely to have children within a marriage as non-stepfathers, although men with three stepchildren show decreased fertility. Among men age 45 and older, stepfathers have lower lifetime fertility than non-stepfathers, although the difference disappears when men’s age at first marriage is controlled for. Additionally, stepfathers have significantly higher fertility than men who never marry. The results suggest that some men become stepfathers to procure mates and fertility benefits that they would otherwise have been unlikely to obtain; for these men, raising other men’s children serves as a form of mating effort.

The Biodemography of Modern Women: Tradeoffs When Resources Become Limiting

Life history theory postulates tradeoffs of current versus future reproduction; in both developed and developing nations today, women face evolutionarily novel versions of these tradeoffs. Here we use a nonlinear dynamic model to explore: [1] the general issues of tradeoffs of education, work, and current fertility; [2] some specific examples (e.g., what increase in fertility will compensate for particular delays of age at first birth under given conditions). Finally, we model a largely unrecognized issue. Demographic transitions of the past have been characterized by decreases in fertility accompanied by (sometimes quite large) increases in per capita investment in offspring. The Rio Conference and its followup highlighted the conflicts between low-fertility, high-consumption, versus highfertility, lower consumption strategies — yet we have few ways to make testable predictions about future conflicts. We explore outcomes when impending resource constraints differentially affect short-generation-time-strategists, versus delayed-reproduction-resource-acquirers. The conditions favoring delayed fertility with resource accumulation are highly constrained; under almost all conditions reproduction in the early 20s leads to the greatest lineage success for women in the models.

Father Absence, Childhood Stress, and Reproductive Maturation in South Africa

The hypothesis that father absence during childhood, as well as other forms of childhood psychosocial stress, might influence the timing of sexual maturity and adult reproductive behaviors has been the focus of considerable research. However, the majority of studies that have examined this prediction have used samples of women of European descent living in industrialized, low-fertility nations. This paper tests the father-absence hypothesis using the Cape Area Panel Study (CAPS), which samples young adults in Cape Town, South Africa. The sample contains multiple racial groups (blacks, coloureds [mixed race], and whites) and includes both males and females. Dependent variables include age at menarche, age at first sexual intercourse, and age at first pregnancy. Childhood stress is measured by father absence by age six (either never lived with father or lived with father some but not all years) and an index of childhood exposure to violence (measuring threatened or actual verbal or physical abuse). The hypothesis received no support for effect on age at menarche but was supported for age at first sex and first pregnancy. The model showed stronger support for coloureds and whites than blacks and had no predictive power at all for black males.

Obesity, Diabetes, and Birth Outcomes Among American Indians and Alaska Natives

Objectives To examine the relationships between prepregnancy diabetes mellitus (DM), gestational diabetes mellitus (GDM), and prepregnancy body mass index, with several adverse birth outcomes: preterm delivery (PTB), low birthweight (LBW), and macrosomia, comparing American Indians and Alaska Natives (AI/AN) with other race/ethnic groups. Methods The sample includes 5,193,386 singleton US first births from 2009–2013. Logistic regression is used to calculate adjusted odds ratios controlling for calendar year, maternal age, education, marital status, Kotelchuck prenatal care index, and child’s sex. Results AI/AN have higher rates of diabetes than all other groups, and higher rates of overweight and obesity than whites or Hispanics. Neither overweight nor obesity predict PTB for AI/AN, in contrast to other groups, while diabetes predicts increased odds of PTB for all groups. Being overweight predicts reduced odds of LBW for all groups, but obesity is not predictive of LBW for AI/AN. Diabetes status also does not predict LBW for AI/AN; for other groups, LBW is more likely for women with DM or GDM. Overweight, obesity, DM, and GDM all predict higher odds of macrosomia for all race/ethnic groups. Conclusions for Practice Controlling diabetes in pregnancy, as well as prepregnancy weight gain, may help decrease preterm birth and macrosomia among AI/AN.

The Educational Expectations of South African Youth

Abstract Educational expectations, in particular the relationship between race/ethnicity and educational expectations, have been understudied in less developed countries. We use data from the Cape Area Panel Study (CAPS) to examine the educational expectations of black (African), coloured (mixed race), and white (European ancestry) youth in Cape Town, South Africa. The educational expectations of all three racial groups are high, although coloured youth are less likely than black and white youth to expect to complete postsecondary or postgraduate schooling. Supporting research on educational expectations in the United States and other more developed countries, our findings indicate that socioeconomic status and academic performance matter for educational expectations in South Africa, although their importance varies by racial group. In contrast to U.S. studies that have found effects of family composition for whites only, we found virtually no effects of family composition on the educational expectations of whites or nonwhites. Our findings suggest possible similarities and differences across social contexts in the processes shaping the educational expectations of youth from disadvantaged groups.

Nonmarital First Births and Women’s Life Histories

This paper draws on evolutionary life history theory to examine nonmarital births in the context of women’s ability to secure male parental investment for their offspring. While nonmarital births are usually defined with respect to marital status the day of parturition, we adopt a more nuanced approach that corresponds to men’s willingness to commit to family obligations. Our approach distinguishes between marriages preceding pregnancy, marriages occurring between pregnancy and birth, marriages immediately following birth, and births that are not followed by marriage to the child’s father. Using retrospective marital and reproductive histories from the Panel Study of Income Dynamics (PSID), we observe a range in women’s life history outcomes (fertility and marital measure) corresponding to this range in male commitment around the time of first birth. Self-selection biases are not examined in this analysis, although their implications are discussed.