Schooling, Local Knowledge and Working Memory: A Study among Three Contemporary Hunter-Gatherer Societies

Principles for Adapting Assessments of Executive Function across Cultural Contexts

Direct assessments of executive functions (EFs) are increasingly used in research and clinical settings, with a central assumption that they assess "universal" underlying skills. Their use is spreading globally, raising questions about the cultural appropriateness of assessments devised in Western industrialized countries. We selectively reviewed multidisciplinary evidence and theory to identify sets of cultural preferences that may be at odds with the implicit assumptions of EF assessments. These preferences relate to motivation and compliance; cultural expectations for interpersonal engagement; contextualized vs. academic thinking; cultural notions of speed and time; the willingness to be silly, be incorrect, or do the opposite; and subject-matter familiarity. In each case, we discuss how the cultural preference may be incompatible with the assumptions of assessments, and how future research and practice can address the issue. Many of the cultural preferences discussed differ between interdependent and independent cultures and between schooled and unschooled populations. Adapting testing protocols to these cultural preferences in different contexts will be important for expanding our scientific understanding of EF from the narrow slice of the human population that has participated in the research to date.

On the Working Memory of Humans and Great Apes: Strikingly Similar or Remarkably Different?

In this article we review publications relevant to addressing widely reported claims in both the academic and popular press that chimpanzees working memory (WM) is comparable to, if not exceeding, that of humans. WM is a complex multidimensional construct with strong parallels in humans to prefrontal cortex and cognitive development. These parallels occur in chimpanzees, but to a lesser degree. We review empirical evidence and conclude that the size of WM in chimpanzees is 2 ± 1 versus Miller's famous 7 ± 2 in humans. Comparable differences occur in experiments on chimpanzees relating to strategic and attentional WM subsystems. Regardless of the domain, chimpanzee WM performance is comparable to that of humans around the age of 4 or 5. Next, we review evidence showing parallels among the evolution of WM capacity in hominins ancestral to Homo sapiens, the phylogenetic evolution of hominins leading to Homo sapiens, and evolution in the complexity of stone tool technology over this time period.

The role of access to finance from different finance providers in production risks of horticulture in Indonesia

This paper aims to investigate the association between perceived production risk of horticultural farms and access to finance from different finance providers. The collection of data was conducted among 434 farmers in Indonesia particularly farmers produced mango, mangosteen, chili and red onion. Production risk was measured by the coefficient of variation, skewness, kurtosis and the 25th percentile. Depending on the risk measure, a lower production risk was found for commercial credit from banks and flexible payments of inputs to kiosks. Conversely, we did not find any lower production risk associated with finance provided by farmers' associations and other sources such as family and friends. Results of this study are useful for policy makers, finance providers and supply chain actors in agriculture. For policy makers, the results of this study can help in designing policy to enhance farmers' access to finance, whereas finance providers and supply chain actors, such as traders, obtain insight into whether their financial provisions effectively reduce production risk.

Ecological and Developmental Perspectives on Social Learning : Introduction to the Special Issue

In this special issue of Human Nature we explore the possible adaptive links between teaching and learning during childhood, and we aim to expand the dialogue on the ways in which the social sciences, and in particular current anthropological research, may better inform our shifting understanding of how these processes vary in different social and ecological environments. Despite the cross-disciplinary trend toward incorporating more behavioral and cognitive data outside of postindustrial state societies, much of the published cross-cultural data is presented as stand-alone population-level studies, making it challenging to extrapolate trends or incorporate both ecological and developmental perspectives. Here, contributors explore how human life history, ecological experience, cumulative culture, and ethnolinguistics impact social learning and child development in foraging and transitioning societies around the world. Using historical ethnographic data and qualitative and quantitative data from studies with contemporary populations, authors interrogate the array of factors that likely interact with cognitive development and learning. They provide contributions that explore the unique environmental, social, and cultural conditions that characterize such populations, offering key insights into processes of social learning, adaptive learning responses, and culture change. This series of articles demonstrates that children are taught culturally and environmentally salient skills in myriad ways, ranging from institutionalized instruction to brief, nuanced, and indirect instruction. Our hope is that this collection stimulates more research on the evolutionary and developmental implications associated with teaching and learning among humans.

The Cultural Foundation of Human Memory

Human memory, as a product of the mind and brain, is inherently private and personal. Yet, arising from the interaction between the organism and its ecology in the course of phylogeny and ontogeny, human memory is also profoundly collective and cultural. In this review, I discuss the cultural foundation of human memory. I start by briefly reflecting on the conception of memory against a historical and cultural background. I then detail a model of a culturally saturated mnemonic system in which cultural elements constitute and condition various processes of remembering, focusing on memory representation, perceptual encoding, memory function, memory reconstruction, memory expression, and memory socialization. Then I discuss research on working memory, episodic memory, and autobiographical memory as examples that further demonstrate how cultural elements shape the processes and consequences of remembering and lay the foundation for human memory. I conclude by outlining some important future directions in memory research.

Short- and long-term memory and age in a traditional tribe (Dani of Papua) and a modern population (Poland)

The different environmental conditions in which people live might challenge memory in different ways. Moreover, the frequency of usage can be a source of improvement of both short- and long-term memory. The aim of our study was to investigate the effects of environmental differences on short- and long-term memory in a traditional versus a contemporary population (Dani of Papua, n = 62; Polish, n = 134). We found that both short- and long-term memory varied in the two populations, living in totally distinct surroundings. However, there were no age differences between Polish and Dani participants in either short- or long-term memory tasks, indicating that culture was not a significant moderator of the memory differences between populations. The differences in short- and long-term memory between the two populations are consistent with the argument that short-term memory plays a more significant role in contemporary societies because of technical developments, the electronic revolution, and reading ability. The lack of an age difference appears to support the assumption that it is age, not culture, that plays a crucial role in the memory performance.

The gist and details of sex differences in cognition and the brain: How parallels in sex differences across domains are shaped by the locus coeruleus and catecholamine systems

Across three different domains, there are similar sex differences in how men and women process information. There tends to be a male advantage in attending to and remembering the gist (essential central information of a scene or situation), but a female advantage in attending to and remembering the details (non-essential peripheral information of a scene or situation). This is seen in emotional memory, where emotion enhances gist memory more for males than for females, but enhances detail memory more for females than for males. It also occurs in spatial memory, where men tend to notice and remember the gist of where they or objects are in space, allowing them to more flexibly manipulate themselves or objects within that space, whereas women tend to recall the details of the space around them, allowing them to accurately remember the locations of objects. Finally, such sex differences have also been noted in perception of stimuli such that men attend to global aspects of stimuli (such as a large letter E) more than women, whereas women attend more to the local aspects (such as the many smaller letter Ts making up the E). We review the parallel sex differences seen across these domains in this paper and how they relate to the different brain systems involved in each of these task domains. In addition, we discuss how sex differences in evolutionary pressures and in the locus coeruleus and norepinephrine system may account for why parallel sex differences occur across these different task domains.

Equifinality in empirical studies of cultural transmission

Cultural systems exhibit equifinal behavior - a single final state may be arrived at via different mechanisms and/or from different initial states. Potential for equifinality exists in all empirical studies of cultural transmission including controlled experiments, observational field research, and computational simulations. Acknowledging and anticipating the existence of equifinality is important in empirical studies of social learning and cultural evolution; it helps us understand the limitations of analytical approaches and can improve our ability to predict the dynamics of cultural transmission. Here, I illustrate and discuss examples of equifinality in studies of social learning, and how certain experimental designs might be prone to it. I then review examples of equifinality discussed in the social learning literature, namely the use of s-shaped diffusion curves to discern individual from social learning and operational definitions and analytical approaches used in studies of conformist transmission. While equifinality exists to some extent in all studies of social learning, I make suggestions for how to address instances of it, with an emphasis on using data simulation and methodological verification alongside modern statistical approaches that emphasize prediction and model comparison. In cases where evaluated learning mechanisms are equifinal due to non-methodological factors, I suggest that this is not always a problem if it helps us predict cultural change. In some cases, equifinal learning mechanisms might offer insight into how both individual learning, social learning strategies and other endogenous social factors might by important in structuring cultural dynamics and within- and between-group heterogeneity.

Child stunting is associated with weaker human capital among native Amazonians

OBJECTIVES

We assessed associations between child stunting, recovery, and faltering with schooling and human capital skills in a native Amazonian society of horticulturalists-foragers (Tsimane').

METHODS

We used cross-sectional data (2008) from 1262 children aged 6 to 16 years in 53 villages to assess contemporaneous associations between three height categories: stunted (height-for-age Z score, HAZ<-2), moderately stunted (-2 ≤ HAZ≤-1), and nonstunted (HAZ>-1), and three categories of human capital: completed grades of schooling, test-based academic skills (math, reading, writing), and local plant knowledge. We used annual longitudinal data (2002-2010) from all children (n = 853) in 13 villages to estimate the association between changes in height categories between the first and last years of measure and schooling and academic skills.

RESULTS

Stunting was associated with 0.4 fewer completed grades of schooling (∼24% less) and with 13-15% lower probability of showing any writing or math skills. Moderate stunting was associated with ∼20% lower scores in local plant knowledge and 9% lower probability of showing writing skills, but was not associated with schooling or math and writing skills. Compared with nonstunted children, children who became stunted had 18-21% and 15-21% lower probabilities of showing math and writing skills, and stunted children had 0.4 fewer completed grades of schooling. Stunted children who recovered showed human capital outcomes that were indistinguishable from nonstunted children.

CONCLUSIONS

The results confirm adverse associations between child stunting and human capital skills. Predictors of growth recovery and faltering can affect human capital outcomes, even in a remote, economically self-sufficient society.

Access to finance from different finance provider types: Farmer knowledge of the requirements

Analysing farmer knowledge of the requirements of finance providers can provide valuable insights to policy makers about ways to improve farmers’ access to finance. This study compares farmer knowledge of the requirements to obtain finance with the actual requirements set by different finance provider types, and investigates the relation between demographic and socioeconomic factors and farmer knowledge of finance requirements. We use a structured questionnaire to collect data from a sample of finance providers and farmers in Java Island, Indonesia. We find that the most important requirements to acquire finance vary among different finance provider types. We also find that farmers generally have little knowledge of the requirements, which are important to each type of finance provider. Awareness campaigns are needed to increase farmer knowledge of the diversity of requirements among the finance provider types.

The evolution of general intelligence

The presence of general intelligence poses a major evolutionary puzzle, which has led to increased interest in its presence in nonhuman animals. The aim of this review is to critically evaluate this question and to explore the implications for current theories about the evolution of cognition. We first review domain-general and domain-specific accounts of human cognition in order to situate attempts to identify general intelligence in nonhuman animals. Recent studies are consistent with the presence of general intelligence in mammals (rodents and primates). However, the interpretation of a psychometric g factor as general intelligence needs to be validated, in particular in primates, and we propose a range of such tests. We then evaluate the implications of general intelligence in nonhuman animals for current theories about its evolution and find support for the cultural intelligence approach, which stresses the critical importance of social inputs during the ontogenetic construction of survival-relevant skills. The presence of general intelligence in nonhumans implies that modular abilities can arise in two ways, primarily through automatic development with fixed content and secondarily through learning and automatization with more variable content. The currently best-supported model, for humans and nonhuman vertebrates alike, thus construes the mind as a mix of skills based on primary and secondary modules. The relative importance of these two components is expected to vary widely among species, and we formulate tests to quantify their strength.

The adaptive nature of culture. A cross-cultural analysis of the returns of local environmental knowledge in three indigenous societies

Researchers have argued that the behavioral adaptations that explain the success of our species are partially cultural, i.e., cumulative and socially transmitted. Thus, understanding the adaptive nature of culture is crucial to understand human evolution. We use a cross-cultural framework and empirical data purposely collected to test whether culturally transmitted and individually appropriated knowledge provides individual returns in terms of hunting yields and health and, by extension, to nutritional status, a proxy for individual adaptive success. Data were collected in three subsistence-oriented societies: the Tsimane' (Amazon), the Baka (Congo Basin), and the Punan (Borneo). Results suggest that variations in individual levels of local environmental knowledge relate to individual hunting returns and to self-reported health, but not to nutritional status. We argue that this paradox can be explained through the prevalence of sharing: individuals achieving higher returns to their knowledge transfer them to the rest of the population, which explains the lack of association between knowledge and nutritional status. The finding is in consonance with previous research highlighting the importance of cultural traits favoring group success, but pushes it forward by elucidating the mechanisms through which individual and group level adaptive forces interact.