A key ingredient of improving  couples' marriages might just be gratitude, according to new University of Georgia research. "We found that feeling appreciated and believing that your spouse values you directly influences how you feel about your marriage, how committed you are to it, and your belief that it will last," said study researchers. The study asked 468 married individuals questions about their financial well-being, communication, and expressions of spousal gratitude. The results indicated that spousal expression of gratitude was the most consistent significant predictor of marital happiness.