The New York Times unwraps the gift within the act of giving.
Tara Parker-Pope writes (excerpt):
. . . [G]iving gifts is a surprisingly complex and important part of human interaction, helping to define relationships and strengthen bonds with family and friends. Indeed, psychologists say it is often the giver, rather than the recipient, who reaps the biggest psychological gains from a gift. . . .
But the biggest effect of gift giving may be on ourselves. Giving to others reinforces our feelings for them and makes us feel effective and caring, Dr. Langer said.