A 2003 study by Emmons and McCullough found that keeping a daily gratitude journal leads to better sleep, reductions of physical pain, a greater sense of well-being, and a better ability to handle change.
In a 2008 study, subjects experiencing gratitude were studied under fMRI (functional Magnetic Resonance Imaging) and it was found that they were influencing their hypothalamus in real-time.
The hypothalamus is the teeny part of your brain that directly influences sleep, eating and stress. Gratitude also simulates the part of the brain associated with the neurotransmitter dopamine - the 'do it again' chemical - which is responsible for the creation of new learning pathways.
Write in the journal. Here's how!