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Biology subjects

Lew-Levy, S.

Publications and source records attributed to Lew-Levy, S..

3 recordsLinked to original sources

Childhood exploration drives population-level innovation in cultural evolution

The societal effects of childrens learning in cultural evolution have been underexplored. Here, we investigate using agent-based models how a propensity for early exploration in childhood contributes to cultural adaptation and the evolution of long human childhood. Using a complex cultural task, we implemented a two-stage strategy for exploring this space - children explore broadly, more likely to learn new behaviours, while adults exploit behaviours already known, incrementally improving them. We found that populations that followed this two-stage strategy achieved higher payoffs in the long term than populations using the two exploration strategies in a random order. Our models point at a just right length of childhood - neither too long, nor too short - allowing individuals enough time to explore before exploiting what they learned. Social learning increased payoffs when agents could copy individuals of a variety of ages. Payoffs decreased under environmental change, especially for long childhoods, because adults did not have enough time to recover between bouts of change.

animal behavior and cognition↗

Woman the Hunter? Female foragers sometimes hunt, yet gendered divisions of labor are real

Gendered divisions of labor are a feature of every known contemporary hunter-gatherer (forager) society. While gender roles are certainly flexible, and prominent and well-studied cases of female hunting do exist, it is more often men who hunt. A new study (Anderson et al., 2023) surveyed ethnographically known foragers and found that women hunt in 79% of foraging societies, with big-game hunting occurring in 33%. Based on this single type of labor, which is one among dozens performed in foraging societies, the authors question the existence of gendered division of labor altogether. As a diverse group of hunter-gatherer experts, we find that claims that foraging societies lack or have weak gendered divisions of labor are contradicted by empirical evidence. We conducted an in-depth examination of Anderson et al. (2023) data and methods, finding evidence of sample selection bias and numerous coding errors undermining the papers conclusions. Anderson et al. (2023) have started a useful dialogue to ameliorate the popular misconception that women never hunt. However, their analysis does not contradict the wide body of empirical evidence for gendered divisions of labor in foraging societies. Furthermore, a myopic focus on hunting diminishes the value of contributions that take different forms and downplays the trade-offs foragers of both sexes routinely face. We caution against ethnographic revisionism that projects Westernized conceptions of labor and its value onto foraging societies.

evolutionary biology↗

BaYaka mothers balance childcare and subsistence tasks during collaborative foraging in Congo Basin

Across cultures, mothers face trade-offs between childcare and other labor. In hunter-gatherer societies, mothers face this choice on a daily basis when deciding either to take infants on foraging trips or to leave them with caregivers in the village. Yet, it remains unclear how the presence of infants in foraging groups constrains mothers mobility during foraging. Here, we present GPS, energy expenditure and food returns data of 359 foraging trips of 23 BaYaka mothers in the Republic of the Congo. We find that mothers spent more time on out-of-village foraging activities when they took infants along, compared to when they left infants behind. However, infant presence in foraging groups does not affect mothers travel distance, travel range, energy expenditure or food returns. Regardless of infant presence, women travel longer and further in a larger area when foraging in groups, compared to when foraging alone, especially in groups with more adults, females and both kin and non-kin. Our results suggest that BaYaka mothers develop ways to accommodate childcare with foraging activities by combining individual-level and group-level behavioural strategies. Our study highlights that group foraging may allow mothers with infants to maintain high mobility, which may have been a key to human range expansion.

ecology↗