Raymond Hames

Hunting and nuclear families: some lessons from the Hadza about men's work

Hadza hunter-gatherers display economic and social features usually assumed to indicate the dependence of wives and children on provisioning husbands and fathers. The wives and children of better Hadza hunters have been found to be better-nourished, consistent with the assumption that men hunt to provision their families. Yet, as is common among foragers, the Hadza share meat widely. Analyses of meat-sharing data confirm that little of the meat from large prey went to the hunters own household. These analyses also show that neither a mans hunting success nor the time he spent hunting made any difference in how much meat his family got from the kills of others. Here we address questions posed by this set of observations. What explains the better nutrition of the children of better hunters if they did not get differential rations of meat? If better hunters got no more meat for their effort and poorer hunters were not punished with less, what incentive could account for the continuing disproportionate contribution that some men made to the groups nutrition? If women were not dependent on their husbands hunting success for meat, an obvious incentive for women to marry hunters disappears. We briefly consider the implications of these patterns for the evolution of marriage and nuclear families.

Birth order, sibling investment, and fertility among Ju/’Hoansi (!Kung)

Birth order has been examined over a wide variety of dimensions in the context of modern populations. A consistent message has been that it is better to be born first. The analysis of birth order in this paper is different in several ways from other investigations into birth order effects. First, we examine the effect of birth order in an egalitarian, small-scale, kin-based society, which has not been done before. Second, we use a different outcome measure, fertility, rather than outcome measures of social, psychological, or economic success. We find, third, that being born late in an egalitarian, technologically simple society rather than being born early has a positive outcome on fertility, and fourth, that number of older siblings and sibling set size are even stronger predictors of fertility, especially for males.

Women's work, child care, and helpers-at-the-nest in a hunter-gatherer society.

Considerable research on helpers-at-the-nest demonstrates the positive effects of firstborn daughters on a mother’s reproductive success and the survival of her children compared with women who have firstborn sons. This research is largely restricted to agricultural settings. In the present study we ask: “Does ‘daughter first’ improve mothers’ reproductive success in a hunting and gathering context?” Through an analysis of 84 postreproductive women in this population we find that the sex of the first- or second-born child has no effect on a mother’s fertility or the survival of her offspring. We conclude that specific environmental and economic factors underlay the helpers-at-the-nest phenomenon.

Meal sharing among the Ye’kwana

In this study meal sharing is used as a way of quantifying food transfers between households. Traditional food-sharing studies measure the flow of resources between households. Meal sharing, in contrast, measures food consumption acts according to whether one is a host or a guest in the household as well as the movement of people between households in the context of food consumption. Our goal is to test a number of evolutionary models of food transfers, but first we argue that before one tests models of who should receive food one must understand the adaptiveness of food transfers. For the Ye’kwana, economies of scale in food processing and preparation appear to set the stage for the utility of meal sharing. Evolutionary models of meal sharing, such as kin selection and reciprocal altruism, are evaluated along with non-evolutionary models, such as egalitarian exchange and residential propinquity. In addition, a modified measure of exchange balance—proportional balance—is developed. Reciprocal altruism is shown to be the strongest predictor of exchange intensity and balance.

Costs and benefits of monogamy and polygyny for Yanomamö women

The Yanomamo Indians of Venezuela occupy drainages south of the upper Orinoco River where they are involved in a moderate level of polygynous relationships. The author analyzed some of the economic costs and benefits of monogamy and polygyny for Yanomamo women. The analysis focuses upon the economic factors which potentially differentiate polygynous and monogamous households in terms of garden size labor time of husbands and wives and the flow of food resources to households. The only statistically significant factor which differentiates monogamous households from polygynous households is that the latter receive more food resources from other households than the former. It may be that polygynous women avoid the potential costs of polygyny because they are economically subsidized by other households in the village because of the high social status of their husbands.

Time Diary versus Instantaneous Sampling: A Comparison of Two Behavioral Research Methods

The accurate collection of unbiased behavioral data is an important component of theory building and ethnographic research. In this article, the authors review two approaches for the collection of behavioral data: time diary and instantaneous sampling. Time diary requires individuals to recall their behavior at specific time intervals; instantaneous sampling relies on researchers observing and recording the behavior of individuals. Each approach has specific strengths and weaknesses. The authors review recent methodological literature on both approaches, identify particular problems with both approaches, and contrast their respective methodological strengths and weaknesses.

Anthropological Data Regarding the Adaptiveness of Hebephilia

It is well established that the great majority of human males are mostattractedsexually topersons inaparticularagerange(Blanchard et al., 2012). According to the category of persons who are most attractive sexually to them, five such preferences are commonly distinguished in adult men: pedophilia (prepubertal children in Tanner Stage 1, generally age 10 or younger), hebephilia (early pubertal children in Tanner Stages 2 and 3, generally ages 11 through 14), ephebophilia (late pubertal adolescents in Tanner Stage 4, generally ages 15 and 16), teleiophilia (adults in Tanner Stage 5, between the ages of physical maturity and physical decline), and gerontophilia (the elderly). One of these preferences (teleiophilia) and possibly a second (ephebophilia) are generally considered normophilic. Two of them (gerontophilia and pedophilia) are generally considered paraphilic.Theremainingpreference(hebephilia)isclassifieddifferently in major diagnostic systems. This difference in the classificationofhebephiliamaynotbeimmediatelyapparent,because themajordiagnosticsystemsalsousediagnosticlabelsdifferently. Twomajormedicalorganizationspublishcorporatelyauthored diagnostic manuals that include definitions of pedophilia: the American Psychiatric Association, which publishes the DSM (Diagnostic and Statistical Manual of Mental Disorders), and the World Health Organization, which publishes the ICD (InternationalStatisticalClassificationofDiseasesandRelatedHealth Problems). Their definitions of pedophilia are somewhat different. The DSM-IV-TR definition is embedded in its diagnostic CriterionA:‘‘Overaperiodofat least6 months,recurrent, intense sexually arousing fantasies, sexual urges, or behaviors involving sexual activity with a prepubescent child or children (generally age 13 years or younger)’’(American Psychiatric Association, 2000, p. 572). The ICD-10 definition of pedophilia is‘‘A sexual preference for children, boys or girls or both, usually of prepubertal or early pubertal age’’ (World Health Organization, 1992, p. 171). It can therefore be seen that the main difference between the ICD-10 and DSM-IV-TR definitions is the inclusion of hebephiliaunder theheadingofpedophilia.Thesecondauthorof this letter (R.B.), a member of the Paraphilias Subworkgroup of the WorkGrouponSexualandGender IdentityDisorders forDSM5, proposed a diagnostic entity for DSM-5 that resembles the ICD-10 model, but with a different name: Pedohebephilic Disorder. In the original proposal (Blanchard, 2010a), this disorder would have three subtypes: pedophilic, hebephilic, and pedohebephilic. In the current version of the proposal, which is still under consideration, the name has been changed to Pedophilic Disorder, in order to harmonize the label as well as the content with its ICD-10 counterpart, and the subtypes have been changed to classic, hebephilic, and pedohebephilic. Franklin (2009) objected to the proposal to roll hebephilia into the diagnosis of Pedophilic Disorder in DSM-5 on the grounds that ‘‘such attractions are evolutionarily adaptive’’ (p. 319).Shedidnotexplainthisargumentanyfurther.Presumably, she meant something along the following lines: In the environmentofevolutionaryadaptedness,menwithasexualpreference for early pubescent females had greater reproductive success, eitherbecause theyacquiredfemalematesnear theonsetof their fecundity and thus prevented them from being impregnated by other men, or because they had more years in which to impregnatetheirmatesthemselves,orboth.AccordingtoFranklin,since hebephilia is of evolutionary design, it cannot be a mental disorder. Franklin’s hypothesis was probably intended to explain hebephiliaonlyinheterosexualmen,sincepubescentboyscannot R. Hames (&) Department of Anthropology, University of Nebraska, Lincoln, NE 68588-0368, USA e-mail: rhames2@unl.edu

A Survey of Non-Classical Polyandry

We have identified a sample of 53 societies outside of the classical Himalayan and Marquesean area that permit polyandrous unions. Our goal is to broadly describe the demographic, social, marital, and economic characteristics of these societies and to evaluate some hypotheses of the causes of polyandry. We demonstrate that although polyandry is rare it is not as rare as commonly believed, is found worldwide, and is most common in egalitarian societies. We also argue that polyandry likely existed during early human history and should be examined from an evolutionary perspective. Our analysis reveals that it may be a predictable response to a high operational sex ratio favoring males and may also be a response to high rates of male mortality and, possibly, male absenteeism. Other factors may contribute, but our within-polyandry sample limits analysis.

Human Behavioral Ecology

Behavioral ecology is an explicitly Darwinian approach to the study of behavior. It emphasizes the adaptive value of behavior patterns of individuals as they attempt to solve social and environmental problems that affect their chances of survival and reproduction. The goal of human behavioral ecology is to explain behavioral diversity as a consequence of environmentally contingent responses made by individuals. While some studies show differential reproductive outcomes, most studies rely on proxy measures of fitness. As such, it is the application of a series of behavioral models from evolutionary biology such as optimal foraging theory, parental investment, life history theory, kin selection, reciprocal altruism, and mating strategies. Much of the research to date has focused on behavioral strategies of producing food, resource transfers, marriage, investing in offspring, and managing social interactions between offspring, mates, kin, and unrelated individuals. A large fraction of this work has been accomplished by anthropologists working among traditional peoples.

Sex differences in spatial abilities: Methodological problems in Hoffman et al.

Hoffman et al. (1) claimed to provide evidence that “nurture” (i.e., residing in a patrilineal vs. matrilineal tribe in India) critically affects sex differences in spatial abilities. Unfortunately, their conclusion is undermined by major problems with their measures of spatial ability and sex equality.