Mum Effect

What is the MUM effect?

The MUM effect is reluctance to communicate undesirable news. It can appear as withholding, delaying or giving a less complete account of bad news than good news.

Tesser, Rosen and Waranch (1973) examined communicator mood and news transmission in a laboratory study. Participants transmitted good news more completely and spontaneously than bad news.

Why hold back? Fear of blame and concern for the recipient are different possibilities, and they call for different responses. The study does not establish one motive in every case or a single workplace policy that removes the reluctance.

A workplace example

A project lead learns that a delivery date will be missed but delays telling the team. The delayed report illustrates the MUM effect. To decide what to change, ask whether the lead expects blame, wants to avoid upsetting others, or has another reason for withholding the news.