We see ourselves as honest communicators. In a poll I conducted last, 97% said that they will pass on a negative news.
However, experiments and real life scenarios indicate the opposite. When it comes to delivering bad news—whether telling a colleague their presentation flopped, warning a friend about a mistake they made, or informing a customer about a problem — many hesitate, soften the truth, or avoid the message altogether.
This hesitation is called the MUM Effect.
The Original Lab Experiment
It coined by social psychologists Sidney Rosen and Abraham Tesser in 1970. They wanted to study how people handle delivering good versus bad news.
The Experiment Setup:
- Participants were told they would relay messages to another person (actually an ‘actor’ in the experiment).
- The news they had to deliver was either positive (“You passed a test”) or negative (“You failed the test”).
- Researchers observed how quickly, accurately, and enthusiastically participants passed on the message.
What They Found:
- People were significantly slower and less willing to pass bad news than good news.
- Even when they had to deliver bad news, they often used softer language, hedged their statements, or tried to avoid it entirely.
- This tendency persisted even when there was no obvious consequence for the messenger—meaning the reluctance wasn’t just about self-protection.
MUM Effect has been tested in many other field and lab experiments, every time it turned out to be true.
MUM Effect can have strong consequences. Here are three practical steps to beat it.
1️⃣ Acknowledge your discomfort—naming it helps you manage it.
2️⃣ Develop the skills – both hard and soft
3️⃣ Soften the tone, not the truth.
Have you experienced MUM effect? How have you overcome it? I invite you to build on the practical steps.
Perspectives 