Hate to say it, but Mother Theresa did get some personal benefit from her charity work: More happiness! To determine how charity work affects the giver, researchers studied the volunteer habits of 29,000 people across 29 states. They found that “formal volunteers” (i.e., Red Cross workers or church volunteers) reported greater health and happiness than non-volunteers did. And the more hours they volunteered, the greater the effect! Surprisingly, donating money didn’t have the same effect though—it was all about donated time and effort. Who knows, your new volunteering gig could improve your love life too: People report a stronger preference for more altruistic mates, probably because it signals someone who will be a great parent or provider. Added bonus!