The Life History of Learning Subsistence Skills among Hadza and BaYaka Foragers from Tanzania and the Republic of Congo

Abstract

Aspects of human life history and cognition, such as our long childhoods and extensive use of teaching, theoretically evolved to facilitate the acquisition of complex tasks. The present paper empirically examines the relationship between subsistence task difficulty and age of acquisition, rates of teaching, and rates of oblique transmission among Hadza and BaYaka foragers from Tanzania and the Republic of Congo. We further examine cross-cultural variation in how and from whom learning occurred. Learning patterns and community perceptions of task difficulty were assessed through interviews. We found no relationship between task difficulty, age of acquisition, and oblique transmission, and a weak but positive relationship between task difficulty and rates of teaching. While same-sex transmission was normative in both societies, tasks ranked as more difficult were more likely to be transmitted by men among the BaYaka, but not among the Hadza, potentially reflecting cross-cultural differences in the sexual division of subsistence and teaching labor. Further, the BaYaka were more likely to report learning via teaching, and less likely to report learning via observation, than the Hadza, possibly owing to differences in socialization practices.

Foraging complexity and the evolution of childhood

“…Following recent studies on the ontogeny of subsistence knowledge and ability ( 13 , 30 ), we used a dynamical model of foraging that allowed us to estimate how foraging skill accumulates with age and how skill (a latent variable) relates to observed returns (which vary for reasons other than forager skill). We used a hurdle model to describe both the probability of acquiring any return at all and probability of harvesting a certain amount of resources.…”

“…However, our focus was on the returns of foragers below age 20—more than a decade earlier than the estimated peak of foraging skill—so we did not model senescence. Otherwise, we used the same functional form as Koster et al ( 13 ) and Lew-Levy et al ( 30 ) to describe change in latent foraging skill with age where k is the constant rate of growth in foraging skill and b is an elasticity parameter that determines the proportional change in skill. Skill itself has nonlinear effects on foraging success.…”

Let’s Play at Digging

“…The acquisition of energetic resources depends not only on the progressive knowledge of certain skills or on body size because the energetic output of performing the task has a real influence on foraging proficiency. Although the relationship between the acquisition of complex foraging skills and the ontogenetic factors of human life history traits and cognition is still under debate (Lew-Levy et al, 2021 ), the effects and interactions of body size, strength, and practice on the improvement of subsistence skills remain uncertain. In our experimental approach, we claimed that digging is an energetically expensive activity, although youth of both sexes found it easy to perform in a social and recreational environment.…”

“…Indeed, Mardu and Meriam children are efficient collectors of small prey and marine resources (Bird & Bliege Bird, 2002 , 2005 ; Bliege Bird & Bird, 2002 ). According to Lew-Levy et al ( 2021 ), the difficulty of a task is not related to the age of skill acquisition; Bird and Bliege Bird ( 2002 , 2005 ) highlighted that body size rather than skill seems to limit the energetic return of foraging.…”

Sociocultural drivers of mycological knowledge: insights from Wixarika and Mestizo groups in western Mexico

“…10 ). In addition to that it must be considered that although they have a similar wealth of knowledge, their application in daily life and practical knowledge varies according to their age and the role they play in society [ 119 ].

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