What can you tell me about how forgiving can affect the physical heart (not the emotions but the cardiac system)?
We did a published study of men on a cardiac unit of a hospital. All of the participants had deep hurts from the past. Once they went through the forgiveness process, and four months after the end of that intervention, there was a statistically significant increase in blood flow through the heart as the men recalled the incident of deep hurt against them. This increase in blood flow did not occur for the control group that had the usual instruction of how to help the heart (diet, exercise, and stress-reduction). Here is the reference to this research:
Waltman, M.A., Russell, D.C., Coyle, C.T., Enright, R.D., Holter, A.C., & Swoboda, C. (2009). The effects of a forgiveness intervention on patients with coronary artery disease. Psychology and Health, 24, 11-27.