This means that we have to have criteria for evaluating those decisions, those outcomes, and for deciding upon new courses of action. But what makes the human being as a decision system so highly adaptable, is the ability to review not just the decision processes, but the decision criteria themselves. We can change our minds about the values we hold. Markets render us collectively stupid because there is no place in them where decisions can be reviewed and evaluated. Any decision system, de facto or otherwise, which relies upon individual action will depend heavily upon the characteristics of the actors within it.
Human beings are notoriously short term creatures.
Thus where the collective decision is simply an aggregate of individual decisions, it will produce results which no one wants. You vote for a particular candidate, not because you support her, but to give the other side a bloody nose. Unfortunately a lot of other people decide to do the same and you end up with an MP who is detested by the majority. Human societies can develop ways of counteracting this, of ensuring that most people do what they, and society, need in the long run, because human societies have cultural rules and norms to which people adhere, and institutions which structure the range of possible actions. It must be able to change decisions in response to events, it must be able to review collective decisions and ask whether they are acceptable.