An example is a recent study that declared optimists live longer than pessimists... Okay, that kind of makes sense. Stress is not good for people's bodies. Earlier came another study that said worriers are more intelligent than those who don't worry.
So... the smarter you are, the more you will know about what is going wrong. Be dumb and you can then live longer maybe? I mean an optimist is likely also someone who doesn't bother to stay too informed or limits the areas where they get informed. They also might be someone who has a very protected life and prefers to think everybody else does too-- or that those who don't deserve what they get.
Putting these two (maybe) facts together, the optimist will live longer than the pessimist which likely means the non-worrier lives longer than the worrier. Does that mean we are turning over the future of the world to those who are less intelligent? Likely not as there are always the rich to throw a ringer into any study. Is Rupert Murdock a worrier or a pessimist or does money just make you immune to such concerns?
The recent study that said the world was safer than ever clearly ignored some countries in their findings. One example would be that there are two nations deemed most likely to become failed states... Good news one is right on our border. Better news, the other has the nuclear bomb.