Philip Gable, a professor of psychological and brain sciences at the University of Delaware, might not be able to tell you what you should buy for presents this holiday season. But he can tell you why you bought them.

Gable can talk about the science behind gift-giving and charitable work.

He emphasizes that the significance of a gift contributes to the happiness derived from giving. This takes various forms, from a personal investment of time to a budget-conscious monetary contribution. In other words, it's more than just an obligation. 

Gable studies the interplay of emotion, motivation, personality and cognition, with a focus on how emotions influence our thoughts, motivate our behaviors and are expressed in the brain. (MV/Newswise)