The MUM Effect

The Basic Idea

When you were a kid, you might have experienced a pet passing away. Perhaps your fish had to be flushed down the toilet, but your parents explained he was going to join his friends in the ocean. Or, as you buried your hamster, your parents said she was in a better place now - somewhere she could spin on a wheel forever. The sad truth that your pet had passed was either distorted or softened by your parents. Parents always want to protect their children from sadness and anger, which is why they often minimize unpleasant news. Although their efforts helped in the short-term and stopped you from crying, sugar coating the truth can also have adverse effects. Their consolation did not help you to understand death as a natural part of life.

The Minimizing Unpleasant Message effect, commonly referred to as the MUM effect to reflect parent’s tendency to withhold unpleasant information, describes instances in which people avoid sharing bad news.1 People have a psychological aversion to delivering bad news, not only because they want to protect the person they are telling the news to, but also to protect themselves. You’ve likely heard the expression “shooting the messenger”, which describes our tendency to blame the bearer of bad news. Although the messenger rarely has anything to do with what happened, strong emotions that are brought on by unpleasant news can cause us to irrationally behave and condemn the messenger.

If everyone is averse to communicating bad news, then every time information gets passed on, it will slightly be altered to sound more positive. The MUM effect causes messages to quickly become skewed like in a game of telephone. Since it is such a common phenomenon and can distort people’s perception of reality, knowing more about the MUM effect is important.

Why do people keep mum? We consider two explanations. One explanation maintains that people anticipate discomfort from conveying bad news. They might ruminate over the victim’s plight, empathize with the victim’s distress, or feel guilty for their own good fortune. To avoid these discomforts, would-be communicators keep mum. Their silence services an internal equanimity. [...] Our second explanation for the MUM Effect is a self-presentational account: people experience no discomfort when transmitting bad news; rather, their reluctance is a public display. By affecting the reluctance, people regulate a situated image, avoid an unfavorable impression, and pay homage to a social norm. Lest they seem blithe to others’ misfortune, lest they seem callous and cruel, people keep mum.

– Social psychologists Charles F. Bond and Evan L. Anderson in their 1986 paper “The Reluctance to Transmit Bad News: Private Discomfort or Public Display?”2

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For decades, it has been a commonsense assumption that people tend to avoid delivering bad news. In the 1960s, multiple studies had shown that people tended to sugar coat negative information when they were passing it along. However, most of these studies had confounding variables that impacted the results. For example, in 1960, Keith Davis and Edward Jones conducted an experiment where participants believed they were reading a negative evaluation to the person who had been evaluated as part of a first impression management study.3 The evaluation was rather abusive. Half of the participants were told that they would be able to later meet up with the evaluee to explain and rectify the situation whereas the other half were not told they would have this opportunity. Drawing on the cognitive dissonance theory, which suggests that a feeling of discomfort leads to a change in behavior to reduce the discomfort,4 Davis and Jones predicted that those that would not have the opportunity to later remedy the situation and ensure that their impression was favorable would make more changes to the evaluation to soften the blow. Their results confirmed their hypothesis, however, there were many variables at play, including the fact that participants were focused on impression management. The study supports the MUM effect but only indirectly.

Psychologists Sidney Rosen and Abraham Tesser wanted to conduct an experiment that would rule out external variables and ensure that it was specifically the fact that news was negative that made people averse to sharing the information. They designed an experiment that would show a direct link between the two and discount other influences, including: the recipient’s prior behavior toward the communicator, specified present or anticipated role relationships, the relationship between communicator and the message, and obvious anticipated rewards and punishments as a consequence for delivering the message.5

In Rosen and Tesser’s 1970 study, participants were told they were being recruited to compare deodorant products. While working on the task, they overheard a message that stated “Glenn Lester should call home immediately. There is some very bad/good news he has to get,” depending on whether participants were in the bad news condition or the good news condition. Glenn Lester then showed up. Rosen and Tesser were examining whether the participants would pass on the information to Glenn Lester in full, partially, or not at all.5

Rosen and Tesser found that only two participants gave Glenn Lester the full information as soon as he walked in the room for the bad news condition, compared to nine participants in the good news condition. Those participants in the bad news condition were more likely to tell Glenn Lester that he had to call home for news without indicating whether it was good or bad news and took longer to pass on the information. A self-reporting questionnaire found that participants in both conditions felt equally responsible for passing on the information and were confident that they had understood the message, which diminished confounding variables. Rosen and Tesser concluded that the MUM effect occurs specifically because people avoid sharing negative information.5


Charles Bond and Evan Anderson

Social psychologists who believed the MUM effect doesn’t occur because people genuinely feel bad when passing on bad news but because they want to be perceived as caring individuals.2 They speculated that in studies when people are asked why they withheld information, they want to portray themselves as empathetic and concerned, but really, they withhold negative information to avoid an unfavorable impression. In their study, Bond and Anderson asked participants to act as test administrators who had to give the results to a confederate. They found that participants who were told that the test-taker could see them through a two-way mirror were much slower to deliver negative test results than positive results, whereas when they were told they could not see them, they delivered positive and negative test results at equal speed. Their results supported their belief that the MUM effect occurs because people avoid being perceived in a negative light.2

Penelope Brown and Stephen Levinson

Linguists who proposed the politeness theory. The politeness theory suggests that people employ two different strategies in order to ‘save face’. Negative politeness strategies, like deference, are performed to avoid offense. Positive politeness strategies like emphasizing friendliness are performed to avoid offense. Both types of politeness strategies might be employed as a result of the MUM effect.6

Fiona Lee

Psychologist who was interested in how bad news was transmitted instead of assessing whether it is transmitted. Drawing from Brown and Levinson’s politeness theory, Lee found that the MUM effect does not cause people to completely avoid passing on bad news but to find creative ways to soften the blow. She found that individuals, especially women, were more likely to use positive politeness strategies when communicating bad news.7


The MUM effect might occur for several reasons. Three main causes are identified: the self-concern factor, concern for the recipient factor, and the ambiguous norms factor.

The self-concern factor includes influences like fear that people will be angry or think of the communicator badly if they are the bearer of bad news. Individuals might feel guilty that they themselves are not experiencing hardship or want to avoid putting themselves in a somber mood to appropriately deliver the bad news.1

The concern for the recipient factor is often the self-reported reason for displaying the MUM effect. People assume that others don’t want their day ruined by being told bad news so they avoid telling them for as long as possible.1

The ambiguous norms factor describes people’s ambivalence as to whether they are the appropriate person to deliver the news. There are potential negative costs associated with delivering bad news; often individuals are unsure if it is ethical to select themselves as the messengers.1

The MUM effect is only seen when news-bearers think the information directly impacts the person they tell. Humans can be morbid, and find it hard to resist sharing general bad news - for example, telling a friend the negative COVID-19 statistics on the news. Distance between the information and the news-reciever dissipates the effect. The relationship between the two individuals can further decrease the MUM effect. A study found that people are more likely to share bad news with a bystander than good news, which may be because they are not directly impacted by the information.10

The problem with sugar coating messages is that it doesn’t just diminish the bad; it distorts the truth. Filtering the truth to avoid discomfort can have serious consequences. Imagine an organization in which each employee decides to color negative news in a slightly more positive light. As the information passes through the ranks, the message will move further and further away from the truth.

The danger of the MUM effect in organizations was studied by Physics Nobel Prize winner Richard Feynman, when he examined the steps that led to the 1986 Challenger space shuttle explosion. When Feynman asked engineers what they thought the probability of engine failure was, they reported between 1 in 200 and 1 in 300. However, when Feynman asked the head of NASA the same question, he answered 1 in 100,000. Those figures show a great discrepancy; it is likely the engineers made their estimates more favorable when they reported to their bosses, who then also embellished the estimates, and so on until the data reached the head of NASA. When negative information is continually distorted as it travels up the ranks, the highest decision-makers end up receiving inaccurate information. The MUM effect may have played a significant role in the Challenger space shuttle tragedy. Evidently, it can have devastating consequences.8


Although it is widely accepted that we favour sharing good news over bad, there is debate whether it is due to our eagerness to transmit positive news or our aversion to sharing negative news. A 2010 study by Jayson Dibble and Timothy Levine, researchers who focus on interpersonal communication, found that both influence the time it takes for individuals to pass on information.9 We may be driven not only by a desire to minimize unpleasant messages, but by a desire to maximize pleasant messages.

Additionally, it is unclear exactly why the MUM effect occurs. Rosen and Tesser were adamant that the only factor that influenced people’s willingness to transmit information was whether it was negative or positive, but Bond and Anderson found that people were only reluctant to share information if they thought it would affect people’s perception of them. The MUM effect still requires further research before we can fully understand its role in our decisions and behaviour.

The Hierarchical MUM Effect

On an individual basis, keeping mum about bad news might not often have devastating effects. However, on a grander scale, such as the Challenger explosion, the MUM effect can have negative consequences.

Distortion of messages, a result of the MUM effect, is a common problem within organizations, specifically when messages travel upwards in a hierarchy. Directions become unclear and incorrect information is passed on. Due to the severity of the potential consequences, psychologists are particularly interested in vertical dyadic messages - how to improve the communication between leaders and subordinates.

Professor of Communications Janet Fulk and expert of Customer Research & Insights Sirish Mani conducted a study in 1986 that examined the impact of the MUM effect in hierarchical organizations and sought to understand which variables influence distorted communication.11 Through a literature review, Fulk and Mani identified four different ways that messages become distorted: gatekeeping, summarization, withholding, and general distortion.11

Gatekeeping means that not all received information is passed upward. Summarization occurs when emphasis is given to various parts of the message, while other parts are kept brief. Withholding refers to the withholding of useful information, and general distortion involves actively changing the information received.11

Through their literature review, the researchers found that the superior’s power, the subordinate’s trust in their supervisor, the perception of a supervisor’s influence in the organization, and the subordinate’s aspirations for upward mobility all impact the likeness of the MUM effect.

Fulk and Mani wanted to investigate whether the stress of a subordinate’s role and their perception of their supervisor’s communication behaviors further influenced the MUM effect. They recruited over 300 clerical and managerial employees of a large public utility to participate in their study. Those participants represented 16 different job classifications and were in eight different hierarchical ranks. Participants were given questionnaires that would help to identify subordinate’s perception of their supervisors’ communication style and their stress levels. The questionnaire also asked them about their own experience with various distortion techniques. They were promised anonymity to ensure all spoke freely. 11

The results showed supervisors’ communication behaviours does influence how likely subordinates are to be impacted by the MUM effect. If they trusted their supervisor and perceived their communication behaviour as supportive, subordinates were less likely to distort information, especially through gatekeeping. If a supervisor communicated frequently with their subordinates, subordinates also followed suit.11

Fulk and Mani also found that role ambiguity led to increased distortion. This finding supports the ‘ambiguous norms factor’ - the hesitancy brought on by an individual's uncertainty whether they are the person responsible for passing on bad news.11

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  1. MUM Effect. (n.d.). Retrieved June 15, 2021, from
  2. Bond, C. F., & Anderson, E. L. (1986). The Reluctance to Transmit Bad News: Private Discomfort or Public Display? Journal of Experimental Social Psychology, 23(2), 176-187.
  3. Davis, K. E., & Jones, E. E. (1960). Changes in Interpersonal Perception as a Means of Reducing Cognitive Dissonance. The Journal of Abnormal and Social Psychology, 61(3), 402-410.
  4. McLeod, S. (2018, February 5). Cognitive Dissonance. Simply Psychology.
  5. Rosen, S., & Tesser, A. (1970). On reluctance to communicate undesirable information: The MUM effect. Sociometry, 33(3), 253.
  6. Penelope Brown and Stephen Levinson's Politeness Theory. (n.d.). ELLO. Retrieved June 15, 2021, from
  7. Lee, F. (1993). Being polite and keeping MUM: How bad news is communicated in organizational Hierarchies1. Journal of Applied Social Psychology, 23(14), 1124-1149.
  8. Sutton, R. (2010, June 5). The Mum Effect and Filtering in Organizations: The "Shoot The Messenger" Problem. Psychology Today.
  9. Dibble, J. L., & Levine, T. R. (2010). Breaking Good and Bad News: Direction of the MUM Effect and Senders’ Cognitive Representations of News Valence. Communication Research, 37(5), 703-722.
  10. MUM effect. (2016, January 27). Psychology. Retrieved June 15, 2021, from
  11. Fulk, J., & Mani, S. (1986). Distortion of communication in hierarchical relationships. Annals of the International Communication Association, 9(1), 483-510.

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