Fatherhood & Health:

Fatherhood - Evolution and Human Paternal Behavior
P B Gray & K G Anderson; 2012

Fatherhood appears to have both protective and deleterious impacts on men's health. The parenting of young children tends to negatively impact marital quality, meaning that men lose some of the beneficial effects of affiliative pair-bonds. Male mental health may suffer, especially if his partner is also struggling with mental health difficulties. Sleep and sexual challenges may exacerbate these difficulties. Young children, particularly those in daycare, can also serve as disease vectors (for example, Hillis et al. 1992), presenting a father with greater exposure to transmissible diseases. The outcome of these types of issues is that fathers of young children may have compromised health.

Yet as those children age, men's health may rebound. The strains of caring for young children wane. Those children may provide social and material support to aging parents. Perhaps an older father, living somewhere without a Social Security check to cash, is supported partly by the sons or daughters he raised to adulthood. Put all of these health and fatherhood variables together, and maybe observations like the following make sense. As shown in a U.S. study of approximately five thousand adults, the effects of fatherhood altered across a man's life and his children's ages (see E. E. Bartlett 2004). In this large U.S. study, among married men aged forty years or younger, 8.9% of fathers but only 1.1% of married men without children rated their health as fair or poor. In the same study, among married men aged forty-one to sixty-four, 16.5% of married fathers with children but 22.7% of married men without children rated their health as fair or poor. Similarly, in an Australian study, fathers of preschool-aged children reported worse health than fathers did of older children (Hewitt, Baxter, and Western 2006). These data suggests that earlier in life fatherhood may be a drain on a man's health, but that same relationship may have later, beneficial effects. This pattern appears to be the overarching perspective on fatherhood and health.

[This excerpt doesn't seem to be based on very hard data, but I think it makes some interesting points.]

Sex Differences in Mathematical Reasoning Ability at Age 13: Their Status 20 Years Later

Sex Differences in Mathematical Reasoning Ability at Age 13: Their Status 20 Years Later
Camilla P. Benbow, David Lubinski, Daniel L. Shea, and Hossain Eftekhari-Sanjani; 2000


Abstract

Reported is the 20-year follow-up of 1,975 mathematically gifted adolescents (top 1%) whose assessments at age 12 to 14 revealed robust gender differences in mathematical reasoning ability. Both sexes became exceptional achievers and perceived themselves as such; they reported uniformly high levels of degree attainment and satisfaction with both their career direction and their overall success. The earlier sex differences in mathematical reasoning ability did predict differential educational and occupational outcomes. The observed differences also appeared to be a function of sex differences in preferences for (a) inorganic versus organic disciplines and (b) a career-focused versus more balanced life. Because profile differences in abilities and preferences are longitudinally stable, males probably will remain more represented in some disciplines, whereas females are likely to remain more represented in others. These data have policy implications for higher education and the world of work.

The Inequality Taboo

The Inequality Taboo
Charles Murray; September 2005

Spatial Ability for STEM Domains: Aligning Over 50 Years of Cumulative Psychological Knowledge Solidifies Its Importance

Spatial Ability for STEM Domains: Aligning Over 50 Years of Cumulative Psychological Knowledge Solidifies Its Importance
Jonathan Wai, David Lubinski, and Camilla P. Benbow; 2009
https://my.vanderbilt.edu/smpy/files/2013/02/Wai2009SpatialAbility1.pdf


Abstract

The importance of spatial ability in educational pursuits and the world of work was examined, with particular attention devoted to STEM (science, technology, engineering, and mathematics) domains. Participants were drawn from a stratified random sample of U.S. high schools (Grades 9 –12, N = 400,000) and were tracked for 11+ years; their longitudinal findings were aligned with pre-1957 findings and with contemporary data from the Graduate Record Examination and the Study of Mathematically Precocious Youth. For decades, spatial ability assessed during adolescence has surfaced as a salient psychological attribute among those adolescents who subsequently go on to achieve advanced educational credentials and occupations in STEM. Results solidify the generalization that spatial ability plays a critical role in developing expertise in STEM and suggest, among other things, that including spatial ability in modern talent searches would identify many adolescents with potential for STEM who are currently being missed.



[Siehe auch den Beitrag / das lesenswerte Kommentar von Christian Schmidt: Räumliches Denken als Voraussetzung für die Naturwissenschaften]

Nurturant Females

Sex, Evolution, and Behavior
Martin Daly & Margo Wilson; 1983

In animals such as ourselves, where parental care is an immense undertaking, the energetic cost of the initial gamete is a negligible proportion of total parental investment. The ovum-sperm disparity seems trivial. Yet nurturance is predominantly a female enterprise in many animals including almost all mammals, and the dimorphism of those little gametes is ultimately to blame. This is because the gamete size distinction has set the stage for some other evolutionary developments that have greatly amplified the initial difference in the parental investment of female and male.

Large ova bias organisms toward female nurture wherever fertilization takes place inside one parent's body because the relative immobility of the ovum assures that, whenever internal fertilization occurs, it takes place within the female. Internal fertilization protects the young from perils like desiccation and predation, thereby greatly increasing each individual ovum's prospects for fertilization and survival. But it also has a cost. By increasing her nurture for each ovum, the female can no longer invest in so many. In one season a ten-year-old cod may release as many as 5 million eggs for external fertilization. No fish with internal fertilization can match the cod's fecundity. But neither will an internal fertilizer suffer the same massive destruction from early deaths and fertilization failures as unparented cod eggs. There are trade-offs between fecundity and nurture.

Once the female is harboring zygotes within her, any further investment in nurturant or protective devices that may then evolve tends most often to be paid by the female, although both parents reap the fitness benefits. Birds and reptiles, for example, construct a protective eggshell at considerable material expense. In several types of animals, mechanisms have evolved to feed the infant while it grows within the maternal body; the mammalian placenta is perhaps the most sophisticated such device. In fact, we mammals have attained a pinnacle of concentrated maternal investment. First there is pregnancy: Prolonged internal gestation and placental nurture are enormous commitments of female's resources that pay off in greatly reduced offspring mortality during the early stages of development. And then, at birth, the mammalian female doesn't even take a recuperative break, for we mammals have invented another major maternal investment - milk.

Internal fertilization, gestation, placentation, lactation: Each of these evolutionary developments has had the effect of concentrating female investment in a decreasing number of offspring. In the evolutionary sequence leading to modern mammals, each advance in the effective nurture of young has amplified the sex difference in parental contributions. Among vertebrate animals with external fertilization (most fish and amphibia), things are very different: If there is any postmating parental care at all, it is at least as likely to be performed by males as by females. In birds, internal fertilization is universal, but so is an early externalization of the developing embryo, with the result that both parents can care for it; biparental investment is the rule. But in mammals, and indeed in most animals with internal fertilization, parental nurture is overwhelmingly female-dominated.

Does a fitness factor contribute to the association between intelligence and health outcomes? Evidence from medical abnormality counts among 3654 US Veterans

Does a fitness factor contribute to the association between intelligence and health outcomes? Evidence from medical abnormality counts among 3654 US Veterans
Rosalind Arden , Linda S. Gottfredson, and Geoffrey Miller; 2009


Abstract

We suggest that an over-arching ‘fitness factor’ (an index of general genetic quality that predicts survival and reproductive success) partially explains the observed associations between health outcomes and intelligence. As a proof of concept, we tested this idea in a sample of 3654 US Vietnam veterans aged 31–49 who completed five cognitive tests (from which we extracted a g factor), a detailed medical examination, and self-reports concerning lifestyle health risks (such as smoking and drinking). As indices of physical health, we aggregated ‘abnormality counts’ of physician-assessed neurological, morphological, and physiological abnormalities in eight categories: cranial nerves, motor nerves, peripheral sensory nerves, reflexes, head, body, skin condition, and urine tests. Since each abnormality was rare, the abnormality counts showed highly skewed, Poisson-like distributions. The correlation matrix amongst these eight abnormality counts formed only a weak positive manifold and thus yielded only a weak common factor. However, Poisson regressions showed that intelligence was a significant positive predictor of six of the eight abnormality counts, even controlling for diverse lifestyle covariates (age, obesity, combat and toxin exposure owing to service in Vietnam, and use of tobacco, alcohol, marijuana, and hard drugs). These results give preliminary support for the notion of a superordinate fitness factor above intelligence and physical health, which could be further investigated with direct genetic assessments of mutation load across individuals.

Genetic and Environmental Influences on Human Psychological Differences

Genetic and Environmental Influences on Human Psychological Differences
Thomas J. Bouchard, Jr. & Matt McGue; 2003


Abstract

Psychological researchers typically distinguish five major domains of individual differences in human behavior: cognitive abilities, personality, social attitudes, psychological interests, and psychopathology (Lubinski, 2000). In this article we: discuss a number of methodological errors commonly found in research on human individual differences; introduce a broad framework for interpreting findings from contemporary behavioral genetic studies; briefly outline the basic quantitative methods used in human behavioral genetic research; review the major criticisms of behavior genetic designs, with particular emphasis on the twin and adoption methods; describe the major or dominant theoretical scheme in each domain; and review behavioral genetic findings in all five domains. We conclude that there is now strong evidence that virtually all individual psychological differences, when reliably measured, are moderately to substantially heritable.