Knowledge-Sharing Networks in Hunter-Gatherers and the Evolution of Cumulative Culture.
Humans possess the unique ability for cumulative culture [1, 2]. It has been argued that hunter-gatherer's complex social structure [3-9] has facilitated the evolution of cumulative culture by allowing information exchange among large pools of individuals [10-13]. However, empirical evidence for the interaction between social structure and cultural transmission is scant [14]. Here we examine the reported co-occurrence of plant uses between individuals in dyads (which we define as their "shared knowledge" of plant uses) in BaYaka Pygmies from Congo. We studied reported uses of 33 plants of 219 individuals from four camps. We show that (1) plant uses by BaYaka fall into three main domains: medicinal, foraging, and social norms/beliefs; (2) most medicinal plants have known bioactive properties, and some are positively associated with children's BMI, suggesting that their use is adaptive; (3) knowledge of medicinal plants is mainly shared between spouses and biological and affinal kin; and (4) knowledge of plant uses associated with foraging and social norms is shared more widely among campmates, regardless of relatedness, and is important for camp-wide activities that require cooperation. Our results show the interdependence between social structure and knowledge sharing. We propose that long-term pair bonds, affinal kin recognition, exogamy, and multi-locality create ties between unrelated families, facilitating the transmission of medicinal knowledge and its fitness implications. Additionally, multi-family camps with low inter-relatedness between camp members provide a framework for the exchange of functional information related to cooperative activities beyond the family unit, such as foraging and regulation of social life.
Department of Anthropology, University College London, London WC1H 0BW, UK. Electronic address: guldeniz.salali.12@ucl.ac.uk.
Gul Deniz
GD
Salali
Department of Anthropology, University College London, London WC1H 0BW, UK.
Nikhil
N
Chaudhary
Department of Anthropology, University College London, London WC1H 0BW, UK.
James
J
Thompson
Royal Botanic Gardens, Kew, Surrey TW9 3AB, UK.
Olwen Megan
OM
Grace
Royal Botanic Gardens, Kew, Surrey TW9 3AB, UK.
Xander M
XM
van der Burgt
Department of Anthropology, University College London, London WC1H 0BW, UK.
Mark
M
Dyble
Department of Anthropology, University College London, London WC1H 0BW, UK.
Abigail E
AE
Page
Department of Anthropology, University College London, London WC1H 0BW, UK.
Daniel
D
Smith
Department of Anthropology, University College London, London WC1H 0BW, UK.
Jerome
J
Lewis
Department of Anthropology, University College London, London WC1H 0BW, UK.
Ruth
R
Mace
Department of Anthropology, University College London, London WC1H 0BW, UK.
Lucio
L
Vinicius
Department of Anthropology, University College London, London WC1H 0BW, UK.
Andrea Bamberg
AB
Migliano
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D003299:Cooperative Behavior; D003468:Cultural Evolution; D015023:Democratic Republic of the Congo; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007398:Interpersonal Relations; D008297:Male; D008875:Middle Aged; D055815:Young Adult