A study in the journal Science finds that for most people a positive attitude peaks early in the morning and again near midnight, but dips mid-morning. And, in general most people are happiest on weekends.
Can the negative thoughts be blamed on work? Not quite, according to researchers, who say work-related stress may play some role -- but that same mid day dip occurs on the weekend too.
Scientists suspect the pattern is due to the effects of sleep and our 24 hour biological clock.