I would love to say that we're all action takers who go out of our way to make this world a better place but unfortunately that's not the case. Most people are observers who sit back, watch things happen, then complain about it when it doesn't happen to their liken, myself included. No one is willing to put forth an effort in order to make needed and wanted changes.
I think we do a lot of watching, rather then take action. It is always someone other than your own problem before the world steps in. I think World War II is a perfect example of that. The people will always sit back and watch until they can't handle it, then act on it.
In terms of the overall big picture of the Earth and the universe in which we live, humans are much more observers as opposed to action-takers. In order for us to take action on something, we have to observe some stimuli first and then react to it. Since there were many more stimuli on Earth before humans, we are observers first and action-takers second.
I think that above all we are observers because there is only so much human beings can change about the world. But we do play a small part in change, usually in a negative manner. Perhaps as we learn more about the world we will be able to take action.
Yes, we are more observers than we are action-takers. An example would be the crsis of global warming. Some people are attempting to take action, but as we all know it would take a global collaboration. Most people are sitting around and watching it happen, complaining about it, and blaming certain people for it.