The remedy is rarely exhortation. It is a change to the situation so that the easier choice is also the better one. Put a number on loyalty and it becomes a target; put a target on it and the number stops meaning what it meant. If you want to see loyalty at work, watch a queue form where there is no reason for one. Ask most people why they did what they did and they will give you a reason; ask them again a week later and the reason will have quietly changed.
Who should read it
A pattern this consistent is not a character flaw. It is a design feature, and design features can be worked with. Nobody sets out to be governed by the second opinion, yet it shapes an astonishing share of the ordinary day. Ask most people why they did what they did and they will give you a reason; ask them again a week later and the reason will have quietly changed. Understanding people turns out to be a more urgent task than changing them, and a great deal harder.
