Just some thoughts on the patterns in life. The idea is not new, is not my invention, it only exists as such...
Negative people are usually surrounded by negative circumstances. And these circumstances, if lasting enough, will then create a negative outlook on life. There are lots of blogs or forums where you can find many people who are stewing in resentment on anything and anyone. But fortunately I know lots of people who will behave in a positive way under the same adverse circumstances.
And where's the pattern here? Negative people will end up in a downward spiral as nobody wants to be around them. And this will spread on: nobody wants to hire them, nobody wants to work with them and nobody wants to socialize with them. And thus they become still more negative. This will also discourage them from resolving problems that they would actually capable of solving. When they try to solve problems, it's often halfheartedly, which increases the likelihood of failure, and so in turn their negativity is reinforced.
Positive people, on the other hand get everything quicker, with more success. Thus their attitude is reinforced. Positivity encourages people to attack the rising problems. And try to solve them. And solving the problem will naturally improve their lives, and not even occasional failures will discourage them.
But I need to emphasized that positive thinking works if it encourages people to take action on things they can change. Also it is of no use if you just think positive and take no action! Although even then it is capable of enriching your life. At least you will be a person with a smile.
And, as far as I'm concerned, it has no power over things you can't control. As you won't be able to make the Earth go backwards.