Duhigg first became fascinated by the power of habit eight years ago, while in Baghdad as a newspaper reporter. There, he met an army major who was conducting a curious experiment in the small town of Kufa: After analyzing taped footage of riots in the area, the major identified a common sequence — first a crowd of Iraqis would gather in the plaza, drawing in spectators and food vendors, then eventually someone would throw a rock and all hell would break loose.
So the major summoned Kufa’s mayor and made a strange request: Get the food vendors out of the plaza. The next time the sequence began to unfold and a crowd started to gather, something different transpired — the crowd snowballed and people started chanting angry slogans, but by dusk, people had gotten hungry and restless. The looked for the familiar kebobs, but they weren’t there. Eventually, the spectators left and the chanters lost steam. By 8PM, everyone was gone.
Upon asking the major how he figured out the clever strategy, Duhigg got the following response: “Understanding habits is the most important thing I’ve learned in the army.”
*Courtesy Brain Pickings –http://www.brainpickings.org/index.php/2012/03/05/the-power-of-habit/
The Linchpin here as we can see were the food vendors, identify the linchpin and you can change everything.