Humans now more or less cooperate in production and distribution to maximize their own pleasure. Pleasure can be divided into direct and indirect ones. Humans can increase their own pleasure through gift-giving behavior in addition to exchange behavior. Here people encounter the question of how much of the savingsable goods that can be used for gifts should be allocated to prepare for one's future anxiety. Gifts to a partner of collaboration are made to the extent that the gift contributes to one's survival by sustaining the collaboration with the partner. This is due to the self-love motive. By excluding this self-love motive from behaviors for indirect pleasure, we focus on the giving behavior, in which an increase in the other's pleasure increases one's own pleasure. We conclude that gifts are considered to be made when the indirect pleasure that arises when a certain amount of gift is given to the other party from one's ability to save is greater than the direct pleasure that arises from allocating it to savings. Further, it is considered that the magnitude relationship between the two is determined by the donor's "subjectivity level" and the giftee's need for gifting.