That exchange of favors that seems so natural with benefits for both parties is also, unfortunately, what gets in people's way before reciprocity ever occurs.

看起来如此自然的对双方都有利的利益上的交流在互惠发生之前也同样给人们的生活造成了阻碍。

youdao

According to the reciprocity theory, the reciprocal altruistic behavior refers to the behavior of two organisms which exchange fitness costs and benefits.

互惠理论指出，互惠利他行为是指两个有机体之间相互交换适合度代价和利益的行为。

youdao

And the idea here is that if there is reciprocity, if there is an exchange, then a receipt of benefits, there can be an obligation even without an act of consent.

因为如果双方存在互惠，如果双方存在交换，然后有一方得到了利益，那么义务就产生了，即使没有双方同意的条款。

youdao

This evidence and the findings of public-goods experiments led the anthropologists to conclude that acceptance and rejection were strongly linked to feelings of fairness and reciprocity in addition to material benefits.

ECONOMIST: Human behaviour