Leakey Research Grant Michelle A. Kline, UCLA Final Research Report
Objectives The objective of the research project is to test predictions of the hypothesis that cumulative cultural evolution is integral to human adaptation, and that humans possess unique social learning capacities that have coevolved with culture. The research is theoretically important to cultural evolutionary theory because these data will constitute the most extensive existing data set on cultural transmission outside the laboratory. The pursuit matters for the study of human origins, because culture is a major source of human adaptability, and because interpreting the early hominin archaeological record accurately requires empirically verified theory about how cultural transmission creates patterns of cultural variation.
The project sought to achieve four aims: (1) test whether subtle teaching is important to social learning in a small-scale society; (2) measure within-group variation in knowledge relevant to adaptive skills; (3) test whether theorized learning biases generate adaptive behavior outside the laboratory; and (4) measure patterns of social interaction to infer the geometry of cultural information networks.
The work took place in villages on Yasawa Island, Fiji. Each village is about 100-
200 people, who subsist mainly on fishing and horticulture. Political units are composed of interrelated clans, a council of elders, and a hereditary chief. There are no local markets, broadcast television, automobiles, or public utilities here. Cell phones have been increasing in prevalence since I began working there in 2008, but lack of reliable electricity, sporadic availability of “recharge” cards, and poor network reception mean their use is still not dependable. Since face-to-face societies like this one are where much of the world’s population lives, and are more similar to the environments to which the human mind has adapted, this is an ideal setting for this study. To address the aims laid out in my proposal, I collected data using mixed methodology. This included focal follows with children aged 6 years old and younger, structured interviews with all members of the village, and video-recorded observations. In addition, I also collected physiological health measures, including “dry” biomarkers such as height, Iight, blood pressure, and hand grip and chest press strength. In addition, I collected “It” biomarkers of overall immune system health. These included on-the-spot measures of HbA1C levels (an indicator of diabetes risk) and white blood cell count, as Ill as C-reactive protein and Epstein-Barr Virus antibodies as measured from dried blood spots.
Achievements As part of our stated project goals, I completed several major activities, including data collection on the following overarching projects: child focal follows, physical health measures, cultural information network interviews, and health/nutrition pile sorts. During the initial project stages, I found that the cooking video
methodology was prohibitively time-consuming and that it was not plausible to maintain a large enough sample size as a result of womens' movement in and out of the village (due life events such as death, marriage, pregnancy, divorce, etc.) I instead gathered data on what it is that women actually prepared on a day-to-day basis for their household, but will still make use of the videos I did record for ethnographic context and for teaching purposes.
Despite the slight change in methods, the project has made progress toward the specific aims as listed above. Data collection is complete on (1) subtle teaching and its importance to teaching in small-scale societies. Initial results from this project are published in a paper in Human Nature (Kline, Henrich, & Boyd, 2013), titled Teaching and the Life History of Cultural Transmission in Fijian Villages. The paper abstract describes its findings:
Much existing literature in anthropology suggests that teaching is rare in non-‐Western societies, and that cultural transmission is mostly vertical (parent-‐to-‐ offspring). However, applications of evolutionary theory to humans predict both teaching and non-‐vertical transmission of culturally learned skills, behaviors, and knowledge should be common cross-‐culturally. Here, we review this body of theory to derive predictions about when teaching and non-‐vertical transmission should be adaptive, and thus more likely to be observed empirically. Using three interviews conducted with rural Fijian populations, we find that parents are more likely to teach than are other kin types, high-‐skill and highly valued domains are more likely to be taught, and oblique transmission is associated with high-‐skill domains, which are learned later in life. Finally, we conclude that the apparent conflict between theory and empirical evidence is due to a mismatch of theoretical hypotheses and empirical claims across disciplines, and we reconcile theory with the existing literature in light of our results.
I have completed preliminary analyses for the focal follow data, which are published in my dissertation (Kline 2013), titled Cultural transmission in the real world: A quantitative study of teaching and cultural learning in the Yasawa Islands, Fiji. The abstract describes the breadth of work included in my
Michelle Kline 5/29/14 10:59 AM Comment: Refs & abstract
dissertation:
The human species is more reliant on cultural adaptation than any other species, but it is unclear how observational learning can give rise to faithful transmission of cultural adaptations. One possibility is that teaching facilitates accurate social transmission by narrowing the range of the inferences that learners make. However, there is wide disagreement about how to define teaching, and how to interpret the empirical evidence for teaching across cultures and species. The work presented here addresses central questions in the study of the evolution of teaching through the presentation of new data and a new theoretical framework for an evolutionary approach to the study of teaching. Chapter 1 presents predictions about when teaching and non-vertical transmission may be adaptive, and uses interview data from Fijian villages to demonstrate that parents are more likely to teach in comparison to other kin, high-skill and highly valued domains are more likely to be taught, and oblique transmission is associated with high-skill domains, which are learned later in life. Chapter 2 reviews three major approaches to the study of teaching—mentalistic, culture-based, and functionalist—and shows how these definitions fail to structure the crosscultural and cross-species study 0f teaching. This chapter proposes a new framework of teaching types based on the learning problems teaching can solve, and reinterprets the existing evidence for teaching in humans and other animals in this framework. This chapter discusses the implications of this new framework, including the roles of cognitive constraints and cooperative dilemmas in how and when teaching evolves. It also offers an explanation as to why some types of teaching are uniquely human, and discusses future research directions. Chapter 3 applies this theoretical framework, develops an ethogram for identifying naturally occurring teaching behavior outside the laboratory, and presents quantitative data from focal follows with young children in Fiji to test predictions about the form and function of teaching behavior. These data demonstrate that, as predicted in Chapter 2, teaching is present in nonwestern societies, more common among close kin, and lower-effort teaching types are more common than higher-effort ones.
I am currently analyzing the focal follow data further, for presentation at the American Anthropological Association Annual Conference in 2014. In addition, I aim to publish these results in two papers: one focused on the overall frequency of teaching and the dyadic and individual features that predict teaching; another which reconciles my findings with closely related research in cognitive development, which focuses more precisely on the communicative cues that teachers and pupils use.
To date, I’ve presented preliminary results from learning/teaching interviews and the focal follow data at the UCLA Center for Behavior, Evolution, and Culture
(2013), the California Workshop on Evolutionary Social Sciences (2013), the American Anthropological Association Annual Conference (2012), and at the Human Behavior and Evolution Society Annual Conference (2013). The latter presentation, in combination with the Human Nature paper, earned me the Best New Investigator award at HBES.
The theoretical grounding for my quantitative work will be published in Behavioral and Brain Sciences, in an article titled How to learn about teaching: an evolutionary framework for the study of teaching in humans and other animals (Kline 2014). The abstract summarizes the article, and the novel framework I created: The human species is more reliant on cultural adaptation than any other species, but it is unclear how observational learning can give rise to the faithful transmission of cultural adaptations. One possibility is that teaching facilitates accurate social transmission by narrowing the range of inferences that learners make. However, there is wide disagreement about how to define teaching, and how to interpret the empirical evidence for teaching across cultures and species. In this article I argue that disputes about the nature and prevalence of teaching across human societies and nonhuman animals are based on a number of deeprooted theoretical differences between fields, and important differences in how teaching is defined. To reconcile these disparate bodies of research, I review the three major approaches to the study of teaching – mentalistic, culture-based, and functionalist – and outline the research questions about teaching that each addresses. I then argue for a new, integrated framework that differentiates among teaching types according to the specific adaptive problems that each type solves, and apply this framework to restructure current empirical evidence on teaching in humans and nonhuman animals. This integrative framework generates novel insights, with broad implications for the study of the evolution of teaching, including the roles of cognitive constraints and cooperative dilemmas in how and when teaching evolves. Finally, I propose an explanation for why some types of teaching are uniquely human, and discuss new directions for research motivated by this framework.
Studies of Cultural Transmission Data collection is also complete on the (2) measure of within-group variation in knowledge relevant to adaptive skills. I collected data on women's knowledge about nutrition/health, and their social networks with respect to food and
cooking, and (in substitution for the video method), weekly records of the meals they cooked and served to their households. The pilot videos that I did collect may be used in the future for a qualitative study of within-culture variation in cooking knowledge, which would open this area of study to a broader Anthropological audience that is not trained in an evolutionary approach.
The data collected during the tenure of the grant will allow me to (3) test whether theorized learning biases generate adaptive behavior in teaching and in cultural transmission among women, and (4) measure patterns of social interaction to infer the geometry of social networks of cultural transmission, by testing whether the most knowledgeable women are central nodes in social networks, and whether women learn preferentially from those who are socially close to them.
Future progress I will continue to analyze the data from the study of teaching, and to publish the results in peer-reviewed journals. I will extend the sample size and reach of these studies in my position as a postdoctoral researcher at Arizona State University School of Human Evolution and Social Change. I have not yet begun data processing on the women's cooking and social networks project, but expect to begin this data analysis during Fall 2014, and to publish the results during the following year.
List of publications Kline, M. A. (in press). How to learn about teaching: an evolutionary framework
for the study of teaching in humans and other animals. Behavioral and Brain Sciences. Kline, M. A. (2013). Cultural transmission in the real world: A quantitative study of teaching and cultural learning in the Yasawa Islands, Fiji. University of California, Los Angeles, Los Angeles. Retrieved from http://escholarship.org/uc/item/9px971xt Kline, M. A., Boyd, R., & Henrich, J. (2013). Teaching and the Life History of Cultural Transmission in Fijian Villages. Human Nature, 24(4), 351–374. doi:10.1007/s12110-013-9180-1