Let me stake out a controversial position. Humility has become a de-valued asset for business leaders, and we need to reverse this trend.

In today’s business and political environment, bluster, boasting and blather seem to be the rage, sometimes literally. The biggest, baddest, boldest claims get the most ink. The mouthiest are frequently celebrated as “disruptors,” and showered with praise, votes and investment capital.

Since I am a public relations and communications advisor, you...