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.

考古证据表明，300,000 至 30,000 年前人类社会行为的特征正在发生重要变化。新的人工制品类型出现并以更高的频率传播。原材料和成品的转移距离越来越远，这意味着更大范围的区域流动以及不同社区之间更频繁和更友好的互动。虽然这些变化发生在环境变异性增加的时期，但生态变化与社会行为转变之间的关系却难以捉摸。在这里，我们探索了一种可能的理论方法和方法，用于理解生态环境如何影响作用于群体间社会行为的选择压力。我们专注于使用基于代理的建模（ABM）在不同生态环境中群体间耐受性的相对优势和劣势。我们评估了在不同环境中群体间互动对生存和资源开发的不同“容忍”水平的相对成本和收益。结果使我们能够推断生态变化与组间行为动态的拟议变化之间的潜在关系。我们得出的结论是，日益恶劣的环境可能导致人类荷尔蒙和情绪反应发生变化，从而导致群体间耐受性增加，我们评估了在不同环境中群体间互动对生存和资源开发的不同“容忍”水平的相对成本和收益。结果使我们能够推断生态变化与组间行为动态的拟议变化之间的潜在关系。我们得出的结论是，日益恶劣的环境可能导致人类荷尔蒙和情绪反应发生变化，从而导致群体间耐受性增加，我们评估了在不同环境中群体间互动对生存和资源开发的不同“容忍”水平的相对成本和收益。结果使我们能够推断生态变化与组间行为动态的拟议变化之间的潜在关系。我们得出的结论是，日益恶劣的环境可能导致人类荷尔蒙和情绪反应发生变化，从而导致群体间耐受性增加，即与“自我驯化”相关的社会行为转变。我们认为，对于被视为“现代人类行为”的现象的出现，群体间容忍度的变化比认知的硬方面或认知适应性或人口规模等其他因素的变化更为节俭。