**6. Conclusions**

In this chapter, we have attempted to describe the causes and consequences of gratitude. After establishing that gratitude enhances happiness, we described some of the known causes of state and trait gratitude. We argued for an appraisal approach to gratitude: people experience the emotion of gratitude when they appraise a situation as indicating that someone has done something important for them. In the investigation of the cognitive antecedents of gratitude, we proposed that the cognitive bias modification paradigm might be particularly helpful. We also discussed other cognitive antecedents that impact gratitude and concluded that more research should be devoted to the nature of the benefactor. In this regard, we find that gratitude to God is a particularly interesting and significant variety of gratitude that should be explored. Although we know less about the causes of trait than state gratitude, we proposed interventions that encourage individuals to look for the good in their life, interpret benefits in a benevolent manner (appraisal training), and reflect in a positive way on their past, should encourage dispositional gratitude.

We then described three theories that help us understand how gratitude enhances SWB: Fredrickson's broaden and build theory [34, 37], Algoe's find, remind, and bind theory [35], and our amplification theory of gratitude [10, 36]. Finally, we explored who gains most from gratitude interventions, and concluded that those who most need gratitude gain the most from gratitude interventions.

In sum, we have seen that gratitude is a critical component of the good life. Research overwhelmingly supports the idea that gratitude enhances happiness. We conclude with a quote from W. J. Cameron:

*It is literally true, as the thankless say, that they have nothing to be thankful for. He who sits by the fire, thankless for the fire, is just as if he had no fire. Nothing is possessed save in appreciation, of which thankfulness is the indispensable ingredient. But a thankful heart hath a continual feast.*

Indeed, without gratitude, it is difficult to see how one could be very happy. As the epigram by Bonhoeffer emphasized, gratitude makes life rich [1]. We conclude that gratitude builds one's happiness because it amplifies the good in one's life.
