Barry S. Hewlett

Social learning among Congo Basin hunter–gatherers

This paper explores childhood social learning among Aka and Bofi hunter–gatherers in Central Africa. Existing literature suggests that hunter–gatherer social learning is primarily vertical (parent-to-child) and that teaching is rare. We use behavioural observations, open-ended and semi-structured interviews, and informal and anecdotal observations to examine the modes (e.g. vertical versus horizontal/oblique) and processes (e.g. teaching versus observation and imitation) of cultural transmission. Cultural and demographic contexts of social learning associated with the modes and processes of cultural transmission are described. Hunter–gatherer social learning occurred early, was relatively rapid, primarily vertical under age 5 and oblique and horizontal between the ages of 6 and 12. Pedagogy and other forms of teaching existed as early as 12 months of age, but were relatively infrequent by comparison to other processes of social learning such as observation and imitation.

Cultural Contexts of Ebola in Northern Uganda

Technical guidelines for the control of Ebola hemorrhagic fever (EHF) indicate that understanding local views and responses to an outbreak is essential. However, few studies with such information exist. Thus, we used qualitative and quantitative methods to determine how local residents of Gulu, Uganda, viewed and responded to the 2000–2001 outbreak of EHF. Results indicated that Acholi people used at least three explanatory models to explain and respond to the outbreak; indigenous epidemic control measures were often implemented and consistent with those being promoted by healthcare workers; and some cultural practices amplified the outbreak (e.g., burial practices). However, most persons were willing to modify and work with national and international healthcare workers.

Ontogeny of prosocial behavior across diverse societies

Humans are an exceptionally cooperative species, but there is substantial variation in the extent of cooperation across societies. Understanding the sources of this variability may provide insights about the forces that sustain cooperation. We examined the ontogeny of prosocial behavior by studying 326 children 3–14 y of age and 120 adults from six societies (age distributions varied across societies). These six societies span a wide range of extant human variation in culture, geography, and subsistence strategies, including foragers, herders, horticulturalists, and urban dwellers across the Americas, Oceania, and Africa. When delivering benefits to others was personally costly, rates of prosocial behavior dropped across all six societies as children approached middle childhood and then rates of prosociality diverged as children tracked toward the behavior of adults in their own societies. When prosocial acts did not require personal sacrifice, prosocial responses increased steadily as children matured with little variation in behavior across societies. Our results are consistent with theories emphasizing the importance of acquired cultural norms in shaping costly forms of cooperation and creating cross-cultural diversity.

Providing Care and Facing Death: Nursing During Ebola Outbreaks in Central Africa

Few studies have focused on describing the experiences of health care workers during rapid killing epidemics. In this article, the views and experiences of nurses during three outbreaks of Ebola hemorrhagic fever (EHF) in Central Africa are examined. These three outbreaks occurred in Kikwit, Democratic Republic of Congo (DRC, 1995); Gulu, Uganda (2000-2001); and Republic of Congo (ROC, 2003). Open-ended and semistructured interviews with individuals and small groups were conducted during the outbreaks in Uganda and ROC; data from DRC are extracted from published sources. Three key themes emerged from the interviews: (a) lack of protective gear, basic equipment, and other resources necessary to provide care, especially during the early phases of the outbreaks; (b) stigmatization by family, coworkers, and community; and (c) exceptional commitment to the nursing profession in a context where the lives of the health care workers were in jeopardy.

Reproductive Interests and Forager Mobility1

Guided by life‐history theory, we examine the contexts in which reproductive interests (e.g., attracting and keeping a spouse) shape forager mobility. Using quantitative intercultural and intra‐cultural mating distance data, we report significant correlations between mating distance and population density not only among foragers but also among farmers. Further, in all of the cultures for which we could find data males on average traveled considerably farther than females in a lifetime, and among Aka foragers of Central Africa age and sex significantly impacted distances traveled. We propose a descriptive model of forager mobility that supplements existing subsistence‐focused models by incorporating reproductive interests at all levels.

Parent-Offspring Weaning Conflicts Among the Bofi Farmers and Foragers of Central Africa

Parentoffspring conflict theory suggests that the reproductive interests of parents and children may conflict when parents want to have another child and an existing child wants continued parental attention and resources. This conflict leads toddlers to throw temper tantrums and use other psychological weapons to maintain parental investment. Few studies employing this theory have considered both the cultural and the biological contexts of weaning. Using systematic qualitative and quantitative data collected among the Bofi farmers and foragers of Central Africa, we examined the influence of cultural schemas and practices, nursing patterns, childs age, maternal pregnancy, and maternal work patterns on childrens responses to the cessation of nursing. As predicted by the theory, Bofi farmer children exhibited high levels of fussing and crying when abruptly weaned while Bofi forager children showed no marked signs of distress. Differences in child care practices associated with the cessation of nursing contributed to this variation, and these practices are linked to broader differences in cultural schemas and social relations. These findings are used to discuss intersections between culture and biology and to show that parentoffspring conflict theory can accommodate a diversity of contexts.

Culture, history, and sex : Anthropological contributions to conceptualizing father involvement

SUMMARY This paper provides a brief overview of anthropological approaches and studies of father involvement with the hopes of providing insights into how father involvement is conceptualized in the United States. The paper reviews four topics: (1) how our culture shapes how we feel about father-child relations; (2) factors cross-cultural studies have identified as being associated with high levels of father involvement; (3) the different roles of fathers during the past 120,000 years of human history; and (4) how biology and male reproductive interest influence father involvement.

Human preferences for sexually dimorphic faces may be evolutionarily novel

Significance It is a popular assumption that certain perceptions—for example, that highly feminine women are attractive, or that masculine men are aggressive—reflect evolutionary processes operating within ancestral human populations. However, observations of these perceptions have mostly come from modern, urban populations. This study presents data on cross-cultural perceptions of facial masculinity and femininity. In contrast to expectations, we find that in less developed environments, typical “Western” perceptions are attenuated or even reversed, suggesting that Western perceptions may be relatively novel. We speculate that novel environments, which expose individuals to large numbers of unfamiliar faces, may provide novel opportunities—and motives—to discern subtle relationships between facial appearance and other traits. A large literature proposes that preferences for exaggerated sex typicality in human faces (masculinity/femininity) reflect a long evolutionary history of sexual and social selection. This proposal implies that dimorphism was important to judgments of attractiveness and personality in ancestral environments. It is difficult to evaluate, however, because most available data come from large-scale, industrialized, urban populations. Here, we report the results for 12 populations with very diverse levels of economic development. Surprisingly, preferences for exaggerated sex-specific traits are only found in the novel, highly developed environments. Similarly, perceptions that masculine males look aggressive increase strongly with development and, specifically, urbanization. These data challenge the hypothesis that facial dimorphism was an important ancestral signal of heritable mate value. One possibility is that highly developed environments provide novel opportunities to discern relationships between facial traits and behavior by exposing individuals to large numbers of unfamiliar faces, revealing patterns too subtle to detect with smaller samples.

Cultural variation in the use of overimitation by the Aka and Ngandu of the Congo Basin.

Studies in Western cultures have observed that both children and adults tend to overimitate, copying causally irrelevant actions in the presence of clear causal information. Investigation of this feature in non-Western groups has found little difference cross-culturally in the frequency or manner with which individuals overimitate. However, each of the non-Western populations studied thus far has a history of close interaction with Western cultures, such that they are now far removed from life in a hunter-gatherer or other small-scale culture. To investigate overimitation in a context of limited Western cultural influences, we conducted a study with the Aka hunter-gatherers and neighboring Ngandu horticulturalists of the Congo Basin rainforest in the southern Central African Republic. Aka children, Ngandu children, and Aka adults were presented with a reward retrieval task similar to those performed in previous studies, involving a demonstrated sequence of causally relevant and irrelevant actions. Aka children were found not to overimitate as expected, instead displaying one of the lowest rates of overimitation seen under similar conditions. Aka children copied fewer irrelevant actions than Aka adults, used a lower proportion of irrelevant actions than Ngandu children and Aka adults, and had less copying fidelity than Aka adults. Measures from Ngandu children were intermediate between the two Aka groups. Of the participants that succeeded in retrieving the reward, 60% of Aka children used emulation rather than imitation, compared to 15% of Ngandu children, 11% of Aka adults, and 0% of Western children of similar age. From these results, we conclude that cross-cultural variation exists in the use of overimitation during childhood. Further study is needed under a more diverse representation of cultural and socioeconomic groups in order to investigate the cognitive underpinnings of overimitation and its possible influences on social learning and the biological and cultural evolution of our species.

Distribution and Numbers of Pygmies in Central African Forests

Pygmy populations occupy a vast territory extending west-to-east along the central African belt from the Congo Basin to Lake Victoria. However, their numbers and actual distribution is not known precisely. Here, we undertake this task by using locational data and population sizes for an unprecedented number of known Pygmy camps and settlements (n = 654) in five of the nine countries where currently distributed. With these data we develop spatial distribution models based on the favourability function, which distinguish areas with favourable environmental conditions from those less suitable for Pygmy presence. Highly favourable areas were significantly explained by presence of tropical forests, and by lower human pressure variables. For documented Pygmy settlements, we use the relationship between observed population sizes and predicted favourability values to estimate the total Pygmy population throughout Central Africa. We estimate that around 920,000 Pygmies (over 60% in DRC) is possible within favourable forest areas in Central Africa. We argue that fragmentation of the existing Pygmy populations, alongside pressure from extractive industries and sometimes conflict with conservation areas, endanger their future. There is an urgent need to inform policies that can mitigate against future external threats to these indigenous peoples’ culture and lifestyles.