Development of embodied capital: Diet composition, foraging skills, and botanical knowledge of forager children in the Congo Basin

The embodied capital theory states that the extended juvenile period has enabled human foragers to acquire the complex foraging skills and knowledge needed to obtain food. Yet we lack detailed data on how forager children develop these skills and knowledge. Here, we examine the seasonal diet composition, foraging behavior, and botanical knowledge of Mbendjele BaYaka forager children in the Republic of the Congo. Our data, acquired through long-term observations involving full-day focal follows, show a high level of seasonal fluctuation in diet and foraging activities of BaYaka children, in response to the seasonal availability of their food sources. BaYaka children foraged more than half of the time independent from adults, predominantly collecting and eating fruits, tubers, and seeds. For these most-consumed food types, we found an early onset of specialization of foraging skills in children, similar to the gendered division in foraging in adults. Specifically, children were more likely to eat fruit and seed species when there were more boys and men in the group, and girls were more likely than boys to collect tuber species. In a botanical knowledge test, children were more accurate at identifying plant food species with increasing age, and they used fruits and trunks for species identification, more so than using leaves and barks. These results show how the foraging activities of BaYaka children may facilitate the acquisition of foraging skills and botanical knowledge and provide insights into the development of embodied capital. Additionally, BaYaka children consumed agricultural foods more than forest foods, probably reflecting BaYaka’s transition into a horticultural lifestyle. This change in diet composition may have significant consequences for the cognitive development of BaYaka children.

[1]  Alyssa N. Crittenden,et al.  The energetics of uniquely human subsistence strategies , 2021, Science.

[2]  A. Henry,et al.  The Cost of Gathering Among the Baka Forager-Horticulturalists From Southeastern Cameroon , 2021, Frontiers in Ecology and Evolution.

[3]  Marie-Lyne Després-Einspenner,et al.  Ecological and evolutionary significance of primates' most consumed plant families , 2021, Proceedings of the Royal Society B.

[4]  Alyssa N. Crittenden,et al.  The Life History of Learning Subsistence Skills among Hadza and BaYaka Foragers from Tanzania and the Republic of Congo , 2020, Human Nature.

[5]  Alyssa N. Crittenden,et al.  Effects of a mixed‐subsistence diet on the growth of Hadza children , 2020, American journal of human biology : the official journal of the Human Biology Council.

[6]  A. Migliano,et al.  Global WEIRDing: transitions in wild plant knowledge and treatment preferences in Congo hunter–gatherers , 2020, Evolutionary Human Sciences.

[7]  Alyssa N. Crittenden,et al.  Who teaches children to forage? Exploring the primacy of child-to-child teaching among Hadza and BaYaka Hunter-Gatherers of Tanzania and Congo , 2020 .

[8]  Alyssa N. Crittenden,et al.  Gender-Typed and Gender-Segregated Play Among Tanzanian Hadza and Congolese BaYaka Hunter-Gatherer Children and Adolescents. , 2020, Child development.

[9]  C. Boesch,et al.  Travel linearity and speed of human foragers and chimpanzees during their daily search for food in tropical rainforests , 2019, Scientific Reports.

[10]  C. Boesch,et al.  Sun, age and test location affect spatial orientation in human foragers in rainforests , 2019, Proceedings of the Royal Society B.

[11]  C. Boesch,et al.  Learning curves and teaching when acquiring nut-cracking in humans and chimpanzees , 2019, Scientific Reports.

[12]  James M. Thompson The social foraging niche of the Mbendjele Bayaka , 2018 .

[13]  A. Sorokowska,et al.  Mapping sweetness preference across the lifespan for culturally different societies , 2018, Journal of Environmental Psychology.

[14]  Richard Inger,et al.  A brief introduction to mixed effects modelling and multi-model inference in ecology , 2018, PeerJ.

[15]  A. Boyette,et al.  Evidence for the Adaptive Learning Function of Work and Work-Themed Play among Aka Forager and Ngandu Farmer Children from the Congo Basin , 2018, Human Nature.

[16]  Daša Bombjaková The role of public speaking, ridicule, and play in cultural transmission among Mbendjele Bayaka forest hunter-gatherers , 2018 .

[17]  K. Ellis-Davies,et al.  How Do Hunter-Gatherer Children Learn Subsistence Skills? , 2017, Human nature.

[18]  B. Hewlett Hunter-Gatherer Childhoods in the Congo Basin , 2017 .

[19]  Stephanie L. Schnorr,et al.  Current views on hunter-gatherer nutrition and the evolution of the human diet. , 2017, American journal of physical anthropology.

[20]  H. Schielzeth,et al.  The coefficient of determination R2 and intra-class correlation coefficient from generalized linear mixed-effects models revisited and expanded , 2016, bioRxiv.

[21]  M. McLennan,et al.  Nutritional Characteristics of Wild and Cultivated Foods for Chimpanzees (Pan troglodytes) in Agricultural Landscapes , 2017, International Journal of Primatology.

[22]  R. Mace,et al.  Knowledge-Sharing Networks in Hunter-Gatherers and the Evolution of Cumulative Culture , 2016, Current Biology.

[23]  R. Byrne,et al.  Spatio‐temporal complexity of chimpanzee food: How cognitive adaptations can counteract the ephemeral nature of ripe fruit , 2016, American journal of primatology.

[24]  D. Bates,et al.  Balancing Type I Error and Power in Linear Mixed Models , 2015, 1511.01864.

[25]  Paul L. Hooper,et al.  Skill ontogeny among Tsimane forager-horticulturalists. , 2015, American journal of physical anthropology.

[26]  Jerome Lewis Pygmy hunter-gatherer egalitarian social organization: the case of the Mbendjele BaYaka , 2017 .

[27]  Carolyn A. Jost Robinson,et al.  Examining short-term nutritional status among BaAka foragers in transitional economies. , 2014, American journal of physical anthropology.

[28]  D. Bates,et al.  Fitting Linear Mixed-Effects Models Using lme4 , 2014, 1406.5823.

[29]  C. Boesch,et al.  Chimpanzees use long-term spatial memory to monitor large fruit trees and remember feeding experiences across seasons , 2013, Animal Behaviour.

[30]  Alyssa N. Crittenden,et al.  Juvenile foraging among the Hadza: Implications for human life history , 2013 .

[31]  C. Boesch,et al.  Taï chimpanzees use botanical skills to discover fruit: what we can learn from their mistakes , 2013, Animal Cognition.

[32]  D. Barr,et al.  Random effects structure for confirmatory hypothesis testing: Keep it maximal. , 2013, Journal of memory and language.

[33]  Hirokazu Yasuoka Dense Wild Yam Patches Established by Hunter-Gatherer Camps: Beyond the Wild Yam Question, Toward the Historical Ecology of Rainforests , 2013, Human ecology: an interdisciplinary journal.

[34]  Claude A. Garcia,et al.  Social learning across the life cycle: cultural knowledge acquisition for honey collection among the Jenu Kuruba, India ☆ , 2012 .

[35]  K. Hayashi,et al.  Addressing the wild yam question: how Baka hunter-gatherers acted and lived during two controlled foraging trips in the tropical rainforest of southeastern Cameroon , 2012 .

[36]  C. Nunn The Comparative Approach in Evolutionary Anthropology and Biology , 2011 .

[37]  Alyssa N. Crittenden The Importance of Honey Consumption in Human Evolution , 2011 .

[38]  Sanford Weisberg,et al.  An R Companion to Applied Regression , 2010 .

[39]  H. Schielzeth,et al.  Cryptic multiple hypotheses testing in linear models: overestimated effect sizes and the winner's curse , 2010, Behavioral Ecology and Sociobiology.

[40]  Alain F. Zuur,et al.  A protocol for data exploration to avoid common statistical problems , 2010 .

[41]  F. Marlowe,et al.  Tubers as fallback foods and their impact on Hadza hunter-gatherers. , 2009, American journal of physical anthropology.

[42]  S. Coldwell,et al.  A marker of growth differs between adolescents with high vs. low sugar preference , 2009, Physiology & Behavior.

[43]  H. Schielzeth,et al.  Conclusions beyond support: overconfident estimates in mixed models , 2008, Behavioral ecology : official journal of the International Society for Behavioral Ecology.

[44]  R. Baayen,et al.  Mixed-effects modeling with crossed random effects for subjects and items , 2008 .

[45]  W. D. Hawthorne,et al.  Woody Plants of Western African Forests: A Guide to the Forest Trees, Shrubs and Lianes from Senegal to Ghana , 2008 .

[46]  S. Goetz,et al.  Expansion of Industrial Logging in Central Africa , 2007, Science.

[47]  Michael Gurven,et al.  How long does it take to become a proficient hunter? Implications for the evolution of extended development and long life span. , 2006, Journal of human evolution.

[48]  Hirokazu Yasuoka THE SUSTAINABILITY OF DUIKER (CEPHALOPHUS SPP.) HUNTING FOR THE BAKA HUNTER-GATHERERS IN SOUTHEASTERN CAMEROON , 2006 .

[49]  Jerome Lewis,et al.  'Logging in the Congo Basin. What hope for indigenous peoples' resources, and their environments? ' , 2006 .

[50]  R. Wrangham,et al.  The rise of the hominids as an adaptive shift in fallback foods: plant underground storage organs (USOs) and australopith origins. , 2005, Journal of human evolution.

[51]  R. Tuttle,et al.  Proceedings of the XIVth congress of the international primatological society , 1993, International Journal of Primatology.

[52]  K. Kitanishi Cultivation by the Baka Hunter-Gatherers in the Tropical Rain Forest of Central Africa , 2003 .

[53]  D. Joiris The framework of Central African hunter-gatherers and neighbouring societies , 2003 .

[54]  A. Robson,et al.  Embodied Capital and the Evolutionary Economics of the Human Life Span , 2003 .

[55]  Eric R. Ziegel,et al.  An Introduction to Generalized Linear Models , 2002, Technometrics.

[56]  F. Marlowe,et al.  Selection for delayed maturity , 2002, Human nature.

[57]  K. Hill,et al.  Age-dependency in hunting ability among the Ache of eastern Paraguay. , 2002, Journal of human evolution.

[58]  Jerome Lewis,et al.  'Putting Hunter-Gatherer and Farmer Relations in Perspective. A Commentary from Central Africa'. , 2002 .

[59]  Hiroaki Sato THE POTENTIAL OF EDIBLE WILD YAMS AND YAM-LIKE PLANTS AS A STAPLE FOOD RESOURCE IN THE AFRICAN TROPICAL RAIN FOREST , 2001 .

[60]  Kim Hill,et al.  A theory of human life history evolution: Diet, intelligence, and longevity , 2000 .

[61]  K. Milton,et al.  A hypothesis to explain the role of meat‐eating in human evolution , 1999 .

[62]  S. Kirchengast Weight status of adult !Kung San and Kavango people from northern Namibia. , 1998, Annals of human biology.

[63]  Kim Hill,et al.  Ache Life History: The Ecology and Demography of a Foraging People , 1995 .

[64]  K. Kitanishi Seasonal Changes in the Subsistence Activities and Food Intake of the Aka Hunter-Gatherers in Northeastern Congo , 1995 .

[65]  Nicholas Blurton Jones,et al.  Foraging Returns of !Kung Adults and Children: Why Didn't !Kung Children Forage? , 1994, Journal of Anthropological Research.

[66]  C. Hladik,et al.  Perception and utilization of rain forest fruits and honey by the Aka Pygmies (Central African Republic) , 1994 .

[67]  T. Smyth Tropical Forests, People and Food: Biocultural Interactions and Applications to Development , 1994 .

[68]  K. Kitanishi The Exchange of Forest Products (Irvingia nuts) between the Aka Hunter-gatherers and the Cultivators in Northeastern Congo. , 1994 .

[69]  K. Milton,et al.  Diet and primate evolution. , 1993, Scientific American.

[70]  A. Hladik,et al.  Wild yams of the African forest as potential food resources , 1993 .

[71]  D. McKey,et al.  Wild yams revisited: Is independence from agriculture possible for rain forest hunter-gatherers? , 1991 .

[72]  Barry S. Hewlett,et al.  Intimate Fathers: The Nature and Context of Aka Pygmy Paternal Infant Care , 1991 .

[73]  S. Bahuchet Food supply uncertainty among the Aka Pygmies (Lobaye, C.A.R.) , 1988 .

[74]  G. Beauchamp,et al.  Longitudinal changes in sweet preferences in humans , 1987, Physiology & Behavior.

[75]  T. Hart,et al.  The ecological basis of hunter-gatherer subsistence in African Rain Forests: The Mbuti of Eastern Zaire , 1986 .

[76]  C. M. Hladik,et al.  Sensibilité gustative différentielle des populations Pygmées et non Pygmées de forêt dense, de Soudaniens et d'Eskimos, en rapport avec l'environnement biochimique. , 1986 .

[77]  Paul S. Martin,et al.  Measuring Behaviour: An Introductory Guide , 1986 .

[78]  S. Bahuchet,et al.  Aka-farmer relations in the northwest Congo basin , 1982 .

[79]  P. Draper,et al.  Social and Economic Constraints on Child Life among the !Kung , 1976 .