DOI: 10.25349/d9kk7b
title: Repercussions of Patrilocal Residence on Mothers’ Social Support Networks Among Tsimane Forager-Farmers

description: While it is commonly thought that patrilocality is associated with worse
 outcomes for women 27 and their children due to lower social support, few
 studies have examined whether the structure 28 of female social networks
 covaries with post-marital residence. Here we analyze scan sample 29 data
 collected among Tsimane forager-farmers. We compare the social groups and
 activity 30 partners of 181 women residing in the same community as their
 parents, their husband’s parents, 31 both or neither. Relative to women
 living closer to their in-laws, women living closer to their 32 parents
 are less likely to be alone or solely in the company of their nuclear
 family (OR: 0.6, 33 95%CI: 0.3-0.9), and more likely to be observed with
 others when engaging in food processing 34 and manufacturing of market or
 household goods, but not other activities. Women are slightly 35 more
 likely to receive childcare support from outside the nuclear family when
 they live closer to 36 their parents (OR=1.8, 95%CI 0.8 - 3.9). Their
 social group size and their children’s probability 37 of receiving
 allocate decrease significantly with distance from their parents, but not
 their in-laws. 38 Our findings highlight the importance of women’s
 proximity to kin, but also indicate that 39 patrilocality per se is not
 costly to Tsimane women.
description: Data collection took place between March 2002 and November 2007
 in 9 separate Tsimane communities. In each community, households were
 sorted into clusters of multiple physically close houses from within which
 researchers could easily monitor the activity of all inhabitants. Clusters
 were then selected for data collection at random without replacement until
 all clusters were sampled. Data collection involved monitoring each member
 of the cluster households for 2-to-3-hour blocks between 7AM and 7PM, with
 point scans every half hour. During point scans, the location, activity,
 and objects of interaction of each individual was recorded. Individuals
 were coded as being in the same social group if they were either a)
 engaged in active conversation or b) within 3 meters of each other, and in
 the same activity group if they were engaged in the same activity. When
 household members from the sampled cluster were absent, their whereabouts,
 activity, and (where possible) companions were ascertained by asking their
 family members.  For this analysis, we selected scans
 of mothers of children under the age of 14, excluding visitors to the
 communities. This resulted in a total sample of 11940 observations of 181
 Tsimane women, ranging in age between 15 and 59 with an average age of 32
 (see table 1). For each woman’s scan we examined the list of individuals
 aged 14 or over who were in a) her social group or b) her activity group
 during the scan, excluding her husband and children. From this list we
 then calculated the total number of individuals engaged in: (1) Any
 activity; (2) Hunting, fishing, or gathering food; (3) Manufacturing
 cloth, bags, or jatata thatch; (4) Garden labor or wage labor,
 and (5) Processing or preparing food. Next, we selected observations of
 the children under the age of seven, which corresponds to the age range
 when Tsimane children require most supervision. This amounted to a sample
 of 21,938 observations of 351 children (52% male). Children were coded as
 receiving extra-familial childcare either if they were recorded receiving
 direct care (e.g., holding, playing, feeding, teaching, etc.) or if they
 were engaged in some social interaction with an individual 11 years or
 older, at which age we determined any social interaction with a child
 under seven could be reasonably construed as childcare based on
 ethnographic insights and existing literature in traditional
 societies [48,49]. Siblings were excluded as providers of childcare in
 this analysis since their presence is not tied to the post-marital
 residence choices of their parents. Because Tsimane adults often supervise
 children passively rather than actively caring for them, we also tested
 whether residence patterns affected children’s probability of being
 unsupervised, which we coded as being in a social group with no
 adults. The post-marital residence choices of the women
 in our sample were coded in two ways. First, we categorized the women as
 being either patrilocal, matrilocal, bilocal, or neolocal based on the
 known residences of their parents and parents-in-law, following Gruitjers
 and Ermisch [50] . Couples for whom no information existed for either set
 of parents were assigned according to the presence of siblings in their
 home community. Accordingly, women coded as neolocal lived in communities
 where none of their or their husbands’ nuclear family lived. Bilocal
 families had at least 1 parent of each of the husband and the wife living
 in the same community. As a robustness check we also analyzed a sub-sample
 of families for whom GPS data existed for at least one parent of both the
 husband and the wife. Starting in 2007, the THLHP and its collaborators
 have collected GPS data for every household, which we used to reconstruct
 a subsample of the households where data was collected. When the precise
 GPS location was unavailable, but the community was known, which generally
 occurred when the parent or in-law lived in a non-sample community, we
 took their location to be the central point of their community, which
 given the distances between communities is a fairly accurate estimate on
 the log scale. This sub-sample included 83 women and 180 children, which
 corresponds to ~50% of the total sample. Using these data, we were able to
 model women’s social group size and children’s probability of receiving
 allocare as a function of the (ln-transformed) distance from the woman’s
 parents (the child’s maternal grandparents) and her in-laws (the paternal
 grandparents).  All analyses were conducted in R
 version 4.1.2. We fit generalized linear multilevel models (GLMMs) using
 the glmmTMB package, which allows for mixed-effect hurdle and
 zero-inflation models. To account for the possible overdispersion of the
 count data, specifically the observed size of women’s social and activity
 groups, we compared multilevel Poisson, negative binomial, and
 zero-inflated Poisson models, all adjusting for mothers’ age, age squared,
 and the time of day of the observation block (morning or afternoon), with
 random intercept terms to control for repeated observations of individuals
 as well as the communities. Mother’s age was selected because of its
 possible causal influence over both residence and social group size.
 Including age squared significantly improved model fit according to
 likelihood ratio tests (Chi-square=9.06, p= 0.011). Time of day also had a
 significant effect on group size in many models, and due to sampling
 randomness may have varied across residence patterns, so was included in
 the model as a control. Likelihood ratio tests
 confirmed that the zero-inflated models were much better fit to the data
 than Poisson and negative binomial models (Electronic Supplementary
 Materials [ESM], table S1). Accordingly, each model fit two sets of
 parameters, one for the zero-inflation component and one for the count
 component. For the analyses of children’s probability of receiving
 non-sibling childcare, we fit multilevel Bernoulli logit models
 controlling for child’s age, with random intercepts terms for the child’s
 ID, their mother’s ID, and the community.
description: R and R Studio.