Patterning of Paternal Investment in Response to Socioecological Change

Ryan Schacht,Karen L Kramer,Helen E Davis

doi:10.3389/fevo.2018.00142

Abstract

Human paternal investment, and that of many other species, is facultatively expressed and dependent on a diverse array of individual, social, and ecological conditions. Well-documented are the various ways in which men invest in offspring and the household. Specifically, local ecology structures pay-offs to male investment and has been shown to be an important predictor of the sexual division of labor. However, while variability in paternal investment has been well-characterized cross-culturally, plasticity within a group in response to changing socioecological conditions remains largely unstudied. To address this, we use recent economic development and market access to explore how changes in socioecology alter behavioral options for men and their resultant investment decisions. Among the monogamous Maya, we find that, associated with the introduction of novel subsistence opportunities and incentives for intensified paternal investment, fathers spend more time in the household, more time in domestic activities and more time interacting with their children. The changes in paternal investment documented here are largely contingent on four conditions: increased efficiency in subsistence brought about by mechanized farming, limited opportunities to engage in wage labor, increased opportunities to invest in offspring quality, and a monogamous mating system. Thus, Maya fathers appear to repurpose found time by furthering investment in their families.

Highlights

Across human societies, men and women typically engage in different yet complementary patterns of parental investment (Murdock and Provost, 1973)
We find that fathers in 2011 are at increased odds to be observed at home (OR = 2.32) and at decreased odds to be spending time in the village (OR = 0.07), at their farm fields (OR = 0.84), or out of town (OR = 0.79; Table 1)
That Maya fathers have their time open to other pursuits, what do they do with this found time? We predicted that in response to economic development and a transition to a skills-based and education dependent economy, fathers would devote a greater proportion of their time budget to the needs of their children

Summary

Introduction

Men and women typically engage in different yet complementary patterns of parental investment (Murdock and Provost, 1973). This type of role specialization, where males and females engage in sex-specific activities within a pairbond, is observed across many animal taxa (Barta et al, 2014). What is distinctive to humans, are the variable ways in which this investment occurs. In some societies males provide most of the calories for subsistence and little childcare (Rasmussen, 1931), in others mothers and fathers contribute relatively to household provisioning and men engage considerably in childcare (Griffin and Griffin, 1992; Hewlett, 1993; Kramer, 2009), and still in others men invest little beyond gametes (reviewed in Hewlett and Macfarlan, 2010). While variability has been well-described cross-culturally, within-group plasticity in response to changing socioecological

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Conclusion