DOI: 10.5061/dryad.70rxwdc4t
title: Women’s subsistence networks scaffold cultural transmission among BaYaka foragers in the Congo Basin

description: In hunter-gatherer societies, women’s subsistence activities are crucial
 for food provisioning and children’s social learning, but they are
 understudied relative to men’s activities. To better understand the
 structure of women’s foraging networks, we present data of 230 days
 focal-follows in a BaYaka community. To analyze these data, we develop a
 stochastic block model for repeat observations with uneven sampling. We
 find that women’s subsistence networks are characterized by cooperation
 between kin, gender homophily, and mixed age-group composition. During
 early-childhood, individuals preferentially co-forage with adult kin, but
 those in middle-childhood and adolescence are likely to co-forage with
 non-kin peers, providing opportunities for horizontal learning. By
 quantifying the probability of co-foraging ties across age-classes and
 relatedness levels, our findings provide insights into the scope for
 social learning during women’s subsistence activities in a real-world
 foraging population and provide ground-truth values for key parameters
 used in formal models of cumulative cultural change.
description: We collected data in collaboration with the BaYaka people of the
 Republic of the Congo. We conducted daily focal-follows of BaYaka women’s
 subsistence groups over a nearly year-long period in 2015 and 2016. Across
 230 days of sampling, we collected data from 60 individuals (32 females)
 in one BaYaka camp. During the study period, however, camp composition
 fluctuated as some individuals joined and left the community. To account
 for variation in “risk of co-foraging” introduced by such changes in camp
 composition, we recorded daily camp composition across the 230-day period
 and defined the model to account for the probability of co-foraging
 conditional on coresidence in-camp on the same day.  We
 constructed subsistence networks that included the entire-community using
 focal-follow data from five BaYaka women. We followed each focal woman’s
 expeditions from the moment the focal woman left the camp until her
 return, and we continuously recorded the foraging group composition and
 behaviors of the focal women. Each focal woman was followed, on average,
 for 46 days (SD = 5.24, range = [40, 53]). These focal women represent
 31.25% of the total number of women residing within the camp (N = 16). We
 coded a network tie between two individuals on a given day as being
 present if those two individuals were observed together at any point
 during a daily focal-follow of subsistence activities outside of the camp.
 That is, if individual i and individual j were both present during a
 focal-follow on day 1 of the focal-follow of individual f, we coded
 undirected ties to be present between i-j, j-f, and i-f during that day.
 Within the subsistence activity networks across 230 days, the average
 number of days that each dyad appeared together varied greatly, with an
 average number of 18.79 days (SD = 19.15, range= 0 − 59). Data on genetic
 relatedness, gender, and age-class were collected during household surveys
 that were conducted at the beginning of the study period. We used these
 data to construct a relatedness matrix that contains the coefficient of
 relatedness, r, for each pair of individuals in our sample. In total,
 13.22% of dyads were close kin (0.25 ≤ r ≤ 0.5), 30.62% were distant kin
 (0 &lt; r &lt; 0.25), and 56.2% were non-kin (r = 0). See
 Supplementary Materials for further description of the data.
description: # Women’s subsistence networks scaffold cultural transmission among BaYaka
 foragers in the Congo Basin ## [Requirements for
 analyses:](https://github.com/danielRedhead/bayaka-subsistence-networks#requirements-for-analyses) * R: [https://cran.r-project.org](https://cran.r-project.org/) * STRAND: * cmdstanr: ## [Packages used for data processing and visualisation:](https://github.com/danielRedhead/bayaka-subsistence-networks#packages-used-for-data-processing-and-visualisation) * Rethinking: * tidyverse: [https://www.tidyverse.org](https://www.tidyverse.org/) ## [Details](https://github.com/danielRedhead/bayaka-subsistence-networks#details) To reproduce the results presented in the manuscript, please first go into the 'code/' folder of the repository. It would probably be best to review the many different scripts for data processing, analysis and visualisation. Then, if you would like to reproduce the results reported in the publication, call the run all file that can be found in the repository: ``` source("./run_all.R") ``` Alternatively, you can go into each processing/analysis/visualisation script and run them separately. ## [Data file](https://github.com/danielRedhead/bayaka-subsistence-networks#details) The strand object data (PublicVersion.RData) contains all data used to run models, including dayID, focalID, ind1, ind2, observed together (1: observed being together in a focal woman's foraging group at the day of day ID, 0: not observed in a focal woman's foraging group), camp_together (1: being at camp together at the day of dayID (cohabitants), 0: not being at camp together), gender difference (female-female, different gender, male-male), co-residence (0: not living together in the same household or 1: co-residing in the same household) and relatedness of each dyad. PublicVersion.RData includes five STRAND data objects with different masks: "model_dat_twostep" is the main model object that includes the two-step procedure that we outline in the main manuscript; "model_dat_nomask" is a base model that did not include any masking; "model_dat_onlyfocal" is a model using the only-focal mask; "model_dat_nofocal" is a model that does not include the two-step procedure; "model_dat_twostep_nf" is a model that followed the two-step mask procedure, but also masked dyads in which the focal women appeared.