Evaluating the self‐domestication hypothesis of human evolution

Abstract

“Self‐domestication” has been invoked to understand important aspects of human evolution, integrating physiological, behavioral, and morphological information in a novel way. It proposes that selection for reduced aggression on animals undergoing domestication provides a model for selection favoring prosocial behaviors in humans and for a set of seemingly independent features, which arose as a result of developmental correlation. We review the history of the idea and examine patterns of domestication. A lack of empirical studies on evolutionary rates and variation thwarts meaningful comparison with domestication. The neural crest hypothesis for domestication has great explanatory power but it is difficult to test. We suggest a scenario in which the morphological byproducts of domestication can act as an honest signal of reduced xenophobia. Future studies should test if alternative explanations for the features deemed to result from self‐domestication are mutually exclusive and generate data to test predictions of these hypotheses.

Sex-specific effects of cooperative breeding and colonial nesting on prosociality in corvids

“…equal access to food for all group members) measured during the GSP ( Burkart et al, 2014 ). The latter result fits the self-domestication hypothesis ( Hare et al, 2012 ; Hare, 2017 ), according to which prosociality arises as a by-product of selection against reactive aggression – particularly in males ( Wrangham, 2019 ) – and selection for increased tolerance (see Sánchez‐Villagra and van Schaik, 2019 for a critical appraisal of historical and current theories on self-domestication). While both the cooperative breeding hypothesis and the self-domestication hypothesis acknowledge an underlying link between increased social tolerance and prosociality, the cooperative breeding hypothesis puts emphasis on allomaternal offspring care, whereas the self-domestication hypothesis suggests the decrease of reactive aggression as the crucial factor for the emergence of human-like prosociality.…”

Masculinity and the mechanisms of human self-domestication

“…Work by other authors can be seen to support selective modes similar to the 'social benefits' (Cieri et al, 2014;Hare, 2017;Sánchez Villagra & van Schaik, 2019) and 'execution' (Wrangham, 2014(Wrangham, , 2018(Wrangham, , 2019a(Wrangham, , 2019b hypotheses of human self-domestication. For example, multiple contributions consider the adaptiveness of enhanced human sociability and collaborative capacities, especially via cooperative reproductive effort (Burkart et al, 2014;Gettler, 2010;Hawkes, 2013;Hrdy, 2009;Sterelny, 2011), but also through food sharing at times of need (Dyble et al, 2016;Gurven, 2004;Gurven & Hill, 2009).…”

“…these are: (1) social benefits (Cieri et al, 2014;Hare, 2017;Sánchez Villagra & van Schaik, 2019), whereby improved sociability would provide enhanced survival and fitness due to elevated capacity for cooperation and exchange; (2) collaborative execution (Wrangham, 2018(Wrangham, , 2019a(Wrangham, , 2019b, where sociable group members would conspire to inflict capital punishment on excessively aggressive and dominating individuals; and (3) female mate choice (Cieri et al, 2014;Gleeson & Kushnick, 2018), whereby women preferentially select for less masculine and aggressive male reproductive partners who would be more sociable and inclined to provide paternal investment.…”

Hypotheses for the Evolution of Reduced Reactive Aggression in the Context of Human Self-Domestication

“…It is interesting, therefore, that evidence has recently been increasing for humans Homo sapiens having a domestication syndrome (Leach, 2003; Francis, 2015; Henrich, 2016; Hare, 2017; Hare and Wrangham, 2017; Theofanopoulou et al, 2017; Wilkins, 2017; Benítez-Burraco et al, 2018; Sánchez-Villagra and van Schaik, 2019; Wrangham, 2019). While there are various physiological, behavioral, cognitive, and genetic similarities between H. sapiens and domesticated animals, the anatomical evidence is particularly strong (Leach, 2003).…”