Gladys Siegel looks happy volunteering.

CHAPEL HILL – You may be happy if you vacation in the Bahamas, but you’ll be happier if you volunteer in your community, says UNC’s Barbara Fredrickson.

New research led by Fredrickson, Kenan Distinguished Professor of psychology in the College of Arts and Sciences at the University of North Carolina, found that human bodies recognize at the molecular level that not all happiness is created equal.

Broken down in simple terms, the study found that human cells respond in a healthier way to long-term happiness that derives from a deeper purpose, as opposed to short-term happiness that derives from pleasurable experiences.  The sense of well-being that comes from a “noble purpose” may provide cellular health benefits, whereas “simple self-gratification” may have negative effects, despite an overall perceived sense of happiness, researchers found.

It’s the difference, for example, between getting a promotion and feeling connected to a larger community through a service project.