How are linguistic and cognitive practices shared among individuals (and more broadly) populations and cultures? Further, how are cognitive strategies shared at the local level? Li and colleagues (Li & Gleitman 2002; Li et al 2011; "inter alia") suggest that the variation observed in reference frame practices among populations of the world results from coincidental patterns in education & literacy of certain populations, as well as the interaction of community size and structure with local landscape. In contrast, Levinson and colleagues (Pederson et al. 1998; Levinson 2003; "inter alia") argue that language and culture are the primary conduits for the sharing of linguistic and cognitive practices. This debate stems from renewed interest in Whorf's (1956) Linguistic Relativity Hypothesis, that language influences thought. This dissertation examines the domain of spatial reference frames to test what factors correlate with shared preferences for linguistic and cognitive strategies at the individual and community level. I examine linguistic data from three communities of speakers of Isthmus Zapotec in the Isthmus of Tehuantepec in Oaxaca, Mexico. I utilize discourse data from a referential communication task (197 participants), recall memory data (25 participants), and demographic survey data from all these participants in order to determine patterns of preference for reference frame use in small-scale space as they correlate with community, age, gender, education level, literacy, and L2 Spanish use. Generalized linear mixed effects models are used to determine which of these factors significantly contribute to the use of different types of Geocentric reference frames (Absolute vs. Landmark-based frames). Responses to a landscape entity free-list task (30 participants) are used to calculate a Landscape Salience Index for each community, in order to explore differences between communities in what environmental features are salient to members. The research presented here shows that community membership (and, less robustly, age and gender) predict the use of reference frames anchored to abstracted environmental anchors (e.g. cardinal directions) and local ad-hoc landmarks. I show that variation in frame use is hyper-local (between neighborhoods of the same city). I explain these findings by suggesting that these discourse and cognitive practices are in fact transmitted and maintained via dense multiplex social networks. The findings presented in this dissertation suggest that multiple individual- and community-level factors work in concert to influence the transmission of cognitive practices (specifically spatial reference frames). This work supports the need for more detailed examinations of linguistic and nonlinguistic cognitive practices in social context. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]