Considering that the Bell Curve is able to predict action, not just describe results, we see some interesting possibilities. The bulk of action will reside in the center, while less action is found at the extremes. A classic example is found in politics, where when either of the two major parties put most of their efforts into the extremes, they cannot win an election. This was the big discussion for the Democrats, since policies discussed during the primary were to the left, some extreme left, and there was wonder how the candidates could move toward the center where the bulk of the voters were.
The center is moved right or left through pushing consistently on one extreme or the other. Pushing policies over to the left will ultimately make the bulk of the policy more left leaning. One could see this during FDR's tenure, where the whole of the government was pushed more to the left with many Federal social programs. The entire government was majorily Democratic. Currently, the Republicans have a slim majority in both Congress and Executive branches. But it is interesting that the topics which are currently under review are still centrist work: Federally funded public education, Federal Social Security, Federal health care/medication payments.
These are all as illustration for this:
If you want to get something done beyond what is simply popular, you have to move to one extreme or the other. Figure that the bulk of humanity is in the center, that what passes for popular media is the bulk of the viewers out there. Less popular stuff (the Long Tail) is at one end or the other of that Bell Curve. (One could also say that as far as intelligence, the bulk is at the average, the disadvantaged at one extreme and the extremely enabled are at the other.) If one is going to help humankind to improve in some fashion or other, one would have to push the top end, which would ultimately bring along the rest of it.
Philosophers, such as Buddha, Jesus of Nazereth, John Locke, Hammurabi, King Solomon - all of these have made incredible effects on the state of humankind. Some religious, some in justice, others in economic/governmental thought. These individuals have pushed the bell curve of humanity over to their extreme side. Criminal leaders such as Hitler, Saddam Hussein, Stalin, and others - these worked to move the equation toward their own extreme positions.
How does this work for the average person?
Be the best you can, hold your standards to almost unrealistically high levels, schedule and organize your personal production so that you achieve your goals within your own lifetime. Above all, strive for the best possible solutions and results. These efforts will then move humankind into a more positive direction, regardless. Every action does count, is measured against the whole. To do nothing except be average simply wastes the life you have been given.