Gratitude, appreciation, or thankfulness is a positive emotion or attitude in acknowledgment of a benefit that one has received or will receive. In a religious context, gratitude can also refer to a feeling of indebtedness towards a deity. Most religions prescribe rituals of thanksgiving towards their higher powers; the expression of gratitude to God is a central theme of Christianity and Islam. In contrast to the positive feeling of gratitude, the feeling of indebtedness is a negative reaction to a favor (Tsang, 2006a; Watkins, Scheer, Ovnicek, & Kolts, 2006). Even though our reactions to favors might not always be positive, researchers have found that people express gratitude often. In a 1998 Gallup poll, the majority of Americans said they express gratitude to God (54%) and others (67%) "all the time." Psychological research has demonstrated that individuals are more likely to experience