Yes, I think the the world can change, but not only thinking alone can make the world change into the better. We have a large amount of possibilities on how we can turn the world for the better. If we only apply ourselves and work hand in hand, with a similar goal, for us to reach our destination.
Only "If" we apply ourselves, but I think our mere human nature shall get the best of us, since we would endure harsh trials and these trials will decide if we ever succeed in our goal.
To change the world is a big job to do, and there will be occurrences that will make us leave and, most probably, give-up.
But Yes, the world can change, it only depends if we do...
Well, the fact is that even if we knew the best way to interact for society to improve -and we don't, else there wouldn't be such a variety of laws an morals- we certainly wouldn't know how to make universal the best possible behaviour. Even it's possible that we weren't able to make it individual.
I think it's quite common to be unable to stop doing something that you can easily see is bad for you.
I don't think evolution has been so precise as to give us pleasure just for the strategies that are the best for us. I don't think either that the education we receive helps much to correct the failures.
Can you imagine how frustrating it would be to know how the perfect society should be organised and to be unable not only to enlighten others, but to act yourself the way you know to be the best?
So I think the most important piece of unknown truth there is may very well be the way to learn to take pleasure in what is correct (good for you), and not to take it in what is wrong (bad for you).
Of course, I say all this (correct == good for you, wrong == bad for you) because I have the intuition, certainly not the mathematical proof, that cooperation is good for all the individuals involved. I don't think a society of people that can calculate the best strategy each for himself and know all the rest are able to do the same thing would turn out to be a chaotic criminal mess.