Researchers followed 233 older men who first completed an optimism questionnaire; 14 years later, they reported daily stressors along with positive and negative moods on eight consecutive evenings up to three times over an eight-year span. The researchers found more optimistic men reported not only lower negative mood but also more positive mood (beyond simply not feeling negative). They also reported having fewer stressors which was unrelated to their higher positive mood but explained their lower levels of negative mood.