A 1967 checklist ranks death of a spouse as the single most stressful life event
Psychiatrists Thomas Holmes and Richard Rahe asked patients to rank 43 life events by how stressful they felt, then built a scale where death of a spouse scores 100 points and 'change in sleeping habits' scores 16. Add up a person's events from the past year, and the total statistically predicted their odds of falling ill within the next two.