In the 1960s, I came across a small training manual distributed by the Communist Party that showed how a small group of people – as few as four – could dominate a much larger group and sway the outcome of any action taken by that group. It was called the Diamond Technique. The principle is based on the fact that people in groups tend to be effected by mass psychology. They derive comfort and security from being aligned with the majority, especially if controversy or conflict is involved. Even if they do not like what the majority is doing, if...