90/30 Rule by Eric Budd
Forms of this rule are also known as the IKEA effect (Dan Ariely), Dunning-Kruger effect and self-serving bias. In her 1988 visit to EDS People Systems Division, Mary Jenkins taught us the 90/30 rule: 90% of people think they are in the top 30% of the population. For organizations that have feedback processes in place, this rule is a two-edged sword. Mary worked with Dr. Deming applying his System of Profound Knowledge to work performed by Human Resources professionals.
For most, feedback will conflict with one’s self-image. If one believes one is in the top 30% of the population, hearing a message that says otherwise will create an internal conflict. The message giver may no longer be seen as a trusted source of feedback—regardless of the “facts” surrounding the feedback. The other edge of this 90/30 sword is that feedback providers view themselves with this rule as well. This creates a perspective that most everyone else does not perform as well as the feedback provider could and thus are deserving of feedback from such a perspective. In order to maintain the 90/30 ratio in a feedback providers mind, others must fall into the 70% below the top.
Whether giving or receiving feedback, the 90/30 rule presents a powerful challenge to useful communication between people.