The Atlantic's June cover story by Joshua Wolf Shenk tells the tale of an amazing 72-year study. It was touted by Brooks Tuesday and well worth your time. A taste:
...positive emotions make us more vulnerable than negative ones. One reason is that they’re future-oriented. Fear and sadness have immediate payoffsprotecting us from attack or attracting resources at times of distress. Gratitude and joy, over time, will yield better health and deeper connectionsbut in the short term actually put us at risk. That’s because, while negative emotions tend to be insulating, positive emotions expose us to the common elements of rejection and heartbreak.