Interesting! 

My taiwanese roommate said in Taiwan as a culture if someone feels angry or resentment towards sometime, they would not express it immediately and after 30-40 days, they would let them know that he/she felt unhappy and angered due to his actions, in that way, the anger is not exhibited in full fury and it is mellowed down to avoid any outward damage.

I don't know how they handle the inner pressure by holding up the resentment for so long. 

Either way this mechanism slows down the collateral damage of resentments. 

Another extreme opposite example is Peruvian and other similar cultures. It reminds me of several traits in animal kingdom, nevertheless it must be an apt mechanism to release the stored up resentments of that people.