EN
The present article concerns the importance of the rule of reciprocity. As such, it obliges the recipient of the favour to repay in the future what they were provided with. The aforementioned rule applies to a virtually infinite spectrum of situations. Individuals experience numerous opportunities to express gratitude for what they have received every time an interaction takes place. The rule proves to be so powerful that it is possible to notice its hallmarks even at the most primitive communities. Therefore it seems reasonable to apply it as a tool of social interactions.