Thanksgiving is a time to reflect on trust and to be grateful for its presence in our lives. Originally, Thanksgiving was a celebration of trust between two different peoples, the indigenous Indians and the Pilgrim settlers. Despite their different cultures and religions, they were able to trust one another enough to contribute food to a feast and sit down to dine with one another.
Today Thanksgiving is quintessentially a family celebration. At its best, it is suffused with trust because the family is a locus of trust. Because of the bonds among kin, for most of human history much commerce took place among extended families. And most of the rest of it took place between people who were known to one another. Being a repeat player who must live in a community inspires trust in others, particularly past eras when being ostracized was very costly.
But as civilization developed, communities became larger and the opportunities for gains from trade extended beyond those that could be easily satisfied by family, new institutions had to arise to police trust.