Reciprocity is fundamental to our nature.
“You scratch my back, I scratch yours.”
“An eye for an eye.”
“Do unto others what you would have them do to you.”
It also fosters generosity. If I am generous to you, you are likely to be generous to me.
But a gift goes farther when we pay it forward instead. For one, the person who gave us a gift would not like to have it back. Secondly, paying it forward multiplies the gift. If one person gifted me a great book, I can gift it to three others now. Reciprocity builds bilateral bonds. Paying it forward builds communities.
When you receive a gift, pay it forward rather than pay it back.