Humans are regularly in suboptimal psychophysiological states like stressed or hungry. Previous research has made both claims that such impairments should decrease and that they should increase prosocial behaviour. We describe the overarching theoretical reasoning underlying these opposing predictions. Then we discuss empirical research on the two impairments most frequently studied, acute stress and acute hunger, and we find that neither alters prosocial behaviour clearly in one direction. We argue that this is because even under impairments, humans react flexibly to the incentive structure of the specific social situation they are in. Hence, either prosocial or egoistic tendencies get expressed, depending on which strategy can lead to fulfilment of the need the impairment triggered.

人类经常处于压力或饥饿等次优心理生理状态。以前的研究都声称这种损伤应该减少，并且应该增加亲社会行为。我们描述了这些相反预测背后的总体理论推理。然后，我们讨论了对最常研究的两种损伤（急性压力和急性饥饿）的实证研究，我们发现两者都不会在一个方向上明显改变亲社会行为。我们认为这是因为即使在损伤的情况下，人类也会对他们所处的特定社会情境的激励结构做出灵活的反应。因此，亲社会或利己的倾向会得到表达，这取决于哪种策略可以满足损伤引发的需求.