“The medical portion, deep down in the (frontal) lobe, is the area most heavily interconnected with the amygdala…The amygdala is more active in people who are depressed. It is more active in people who have posttraumatic disorder. It is more active in people who are anxious. The medial area of the frontal cortex plays an inhibitory role: When this area becomes more active, the amygdala shows a decrease in activation. People differ in temperament to the extent in which these areas of the prefrontal cortex are active and the amygdala is correspondingly underactive.
“This difference in temperament due to prefrontal activation sheds new light on some puzzling data. One study of people’s sense of well-being found negligible differences in satisfaction with life between paraplegics, ordinary people, and lottery winners…In short, there is amazingly little connection between one’s life circumstances and our predominant moods….such findings have led to the proposition that each of us has a happiness set point, a biologically determined ratio of good-to-bad moods. And because the set point is biological, life’s upsets or triumphs may budge it for a while, but it will tend to settle back to our customary level…
“So the question then is, how can we strengthen this area that inhibits the amygdala so that we can increase a person’s positive emotions and decrease the destructive emotions?”
~from Destructive Emotions by Daniel Goleman (emphasis mine)