Theoretical and Methodological Approaches to Ecological Changes, Social Behaviour and Human Intergroup Tolerance 300,000 to 30,000 BP

Abstract

Archaeological evidence suggests that important shifts were taking place in the character of human social behaviours 300,000 to 30,000 years ago. New artefact types appear and are disseminated with greater frequency. Transfers of both raw materials and finished artefacts take place over increasing distances, implying larger scales of regional mobility and more frequent and friendlier interactions between different communities. Whilst these changes occur during a period of increasing environmental variability, the relationship between ecological changes and transformations in social behaviours is elusive. Here, we explore a possible theoretical approach and methodology for understanding how ecological contexts can influence selection pressures acting on intergroup social behaviours. We focus on the relative advantages and disadvantages of intergroup tolerance in different ecological contexts using agent-based modelling (ABM). We assess the relative costs and benefits of different ‘tolerance’ levels in between-group interactions on survival and resource exploitation in different environments. The results enable us to infer a potential relationship between ecological changes and proposed changes in between-group behavioural dynamics. We conclude that increasingly harsh environments may have driven changes in hormonal and emotional responses in humans leading to increasing intergroup tolerance, i.e. transformations in social behaviour associated with ‘self-domestication’. We argue that changes in intergroup tolerance is a more parsimonious explanation for the emergence of what has been seen as ‘modern human behaviour’ than changes in hard aspects of cognition or other factors such as cognitive adaptability or population size.

The evolution of human music in light of increased prosocial behavior: a new model

“…There is statistically robust evidence that the increased vulnerability to climate change was the primary cause for hominin extinctions [298]. On the other hand, harsher environments have been proved to favor prosocial behavior, specifically, intergroup tolerance [299]. Challenges of survival in extreme environments often correspond to the presence of special hospitality codes amongst populations that inhabit such environments.…”

The (co)evolution of language and music under human self-domestication

“…This includes smaller skulls/brains (as compared to archaic humans); reduced hair; neotenic features (e.g., extended childhood and increased playing behavior); and particularly, reduced levels of reactive aggression (Shea, 1989;Leach, 2003;Somel et al, 2009;Zollikofer and Ponce de León, 2010;Plavcan, 2012;Fukase et al, 2015;Stringer, 2016). Diverse factors have been hypothesized to trigger HSD, like the rise of co-parenting, the advent of community living, changes in our foraging ecology, climate deterioration, and/or the colonization of new environments (Pisor and Surbeck, 2019;Brooks and Yamamoto, 2021;Spikins et al, 2021). All in all, these factors might have promoted a selection toward less reactive and more prosocial behaviors, thereby instilling in humans the constellation of physical, behavioral, and cognitive changes characteristic to domestication.…”

Did Dog Domestication Contribute to Language Evolution?

“…Reduced environmental stress resulting from generalized fire and tool using ( Domínguez-Rodrigo and Pickering, 2017 ) might also have contributed to our self-domestication, considering the positive effect of decreased environmental stress conditions on prosocial behavior, as seen in bonobos ( Hare et al, 2012 ), island wolves ( Darimont et al, 2014 ), or Florida key deer ( Harveson et al, 2007 ). A final factor contributing to trigger our self-domestication could be the generalized climate deterioration that occurred during the Last Glaciation (spanning from 110 kya to 15 kya), since harsh environments have been proven to favor prosocial behavior too, particularly tolerance ( Spikins et al, 2021 ).…”