Our natural state of being is in relationship, a tango, a constant state of one influencing the other. Just as the subatomic particles that compose us cannot be separated from the space and particles surrounding them, so living beings cannot be isolated from each other... By the act of observation and intention, we have the ability to extend a kind of super-radiance to the world.
If we, on our most fundamental level, are packets of quantum energy constantly exchanging information with this heaving energy sea, it means that all of us connect with each other and the world at the level of the very undercoat of our being. It also means that we have the power to access much more information about the world than we realize.
We have mirror neurons that mirror other human beings. In other words, if I'm smiling it tends to make other people with me smile also. Whether I'm happy or lonely, I will tend to have happy or lonely friends. The same thing happens with actions; if I make an act of generosity it tends to be passed on down through society. So I see small groups as being very important in having an effect on large groups.