Social Distance, Moral Property Right and Value of Gratitude in Dictator Game

Daily life incidents shows that people tend to treat close friends and blood relative better than casual acquaintances and stranger, the concept of social distance only developed in 1925 by an American sociologist named Emory Bogardys. He defined it as the grades and degrees of understanding and intimacy, which characterize presocial and social relations generally.
Merriam-Webster Encyclopedias define property rights as a legal right or interest in or against specific property. The notion of property rights is familiar to standard economic analysis. But the focus on moral property rights that defined by Gachter & Riedl (2005) as rights, as perceived by the individual. They are not, however, abstract legal rights. Rather they denote the subjectively perceived rights that go along with a motivational disposition to defend them.