If you hope to live a really, really long life, turns out it's better to be conscientious than optimistic.   As The Daily Beast reports, Psychologists have created something called the "Big 5," a criterion used to comprehend a human's personality. The five aspects are agreeableness, openness, extroversion, conscientiousness and neuroticism, with each  given a ranking to form a personality understanding. The more conscientious a person, the longer he or she is  likely to live.  So, wipe that smile off your face and get to work!