Blue Monday is total bullshit. Psychologist explains: This is the zombie theory that doesn't want to die

It is extremely difficult to remove information from memory that has already been remembered, even if we already know that it is not true – notes psychologist Prof. in an interview with PAP. Michał Białek from the University of Wrocław, discussing the popularity of the scientifically unconfirmed concept of “Blue Monday”.

Using the example of Blue Monday – the supposedly “most depressing day of the year”, the existence of which is fake news – the scientist explains how the scientific method works, and therefore what tools science has at its disposal to confirm or refute some theses. Blue Monday would fall on the third Monday of January, so this year – January 19.

PAP: Let's assume that someone comes to you and says that they have developed a formula for the worst day of the year. As a scientist, what tools do you have to check whether he is worth believing?

Prof. Michał Białek, moral psychologist from the University of Wrocław: This is a serious and – I must admit – terrible problem of our times. Even I, being a scientist with some experience, do not have the competence to verify maybe even 95%. what other researchers say. Specialization in science is now so narrow that outside my strict domain I almost feel like a layman. Without a deep understanding of the topic, I am often unable to quickly verify every piece of information. At most, I can see if it fits my general knowledge.

However, when it comes to Blue Monday, it is an extreme example of total bullshit. You don't need sophisticated knowledge to see this absurdity.

PAP: Yes, yes. Let's look at the formula by which the “most depressing day of the year” would be calculated. There are elements such as the weather (which differs all over the Earth), to which is added the debt, i.e. the lack of money. There is also the time since Christmas raised to the power of unfulfilled New Year's resolutions. Needless to say, this algorithm is constructed as a joke.

MB: It's obvious here. However, there is a lot of information around us that looks credible at first and second glance. If we want to confirm their reasonableness, it is worth looking for the source of the research – checking whether a given issue exists in academic circulation at all and whether the given content has been published in a peer-reviewed journal. For example, in Google Scholar you can only search scientific literature.

PAP: The existence of Blue Monday has never been confirmed in a peer-reviewed scientific journal. The alleged designation of the most depressing day of the year was announced by journalists – in the press. Could you explain to us what exactly a “peer-reviewed journal” is and why peer review is so important in science?

MB: Reviews are a fuse system. When a scientist writes an article for a scientific journal, the text goes to an editor who sends it to two or three independent reviewers – experts in a given, very narrow field. They check whether the text has “arms and legs”, whether the argument is logical and whether the evidence provided supports the thesis. For about a decade, reviewers have also had access to data collected as part of research.

In the case of Blue Monday, reviewers would ask, “Where are the demographics? Are there actually more psychiatric hospital admissions that day?” Since such data is not available, the article would be rejected.

In good scientific journals, on average, four out of five submitted texts are rejected. The publication process takes a year or two, and reviewers often require the authors to conduct additional research and improve the text. This is a high bar to guarantee quality.

PAP: These are a bit more fuses than in social networking sites, where everyone can come up with some nonsense in two minutes and put it out into the world. But let's get back to Blue Monday: scientific publications include a clause stating whether the author declares a conflict of interest. In the case of Blue Monday, the author of the concept was paid by a travel agency to find the best day to book a trip. Would that be a conflict of interest?

MB: A scientist employed by a company to perform a given task may even unconsciously choose methods that will confirm his hypothesis, because the next assignment depends on it.

PAP: Let's assume that a study passes the review screen, but the error is discovered later. How is erroneous content removed in science?

MB: In science, the gold standard should be replication, i.e. repeating the study by an independent team. In practice, however, only about 0.5–1.5% are replicated. hypotheses.

PAP: So little? Only 1 in 66-200 tests are confirmed? Does that mean the rest isn't true?

MB: That's not the point. Most research is of no interest to anyone, so no one repeats it. Only those results that “break through” to the mainstream are replicated. The most unreliable according to replication rates are nutrition science and sports research, where the replicability level is 15-20%.

PAP: This is less than in psychology, where 30-60% are confirmed in subsequent experiments. research. As for Blue Monday, an attempt at replication was also made – in 2024, an analysis was performed which showed that there is no specific day in January when more suicide attempts or admissions to psychiatric hospitals are made.

MB: Blue Monday can be considered one of the “zombie theories”. Zombie theories are those beliefs that no one among specialists believe in, science “killed” them a long time ago, but they are still alive in public opinion. Another such “zombie theory” is the belief that breakfast is the most important meal of the day (this is the result of an advertising campaign for breakfast cereals). The division of learning styles should also be forgotten – including: into “visual” and “auditory” learners. Science moved away from this in the 1990s, but this belief still persists.

As it is sometimes said: “Theories don't die, the people who believe in them die.” You just have to wait for a generational change, because once you learn nonsense it is almost impossible to get rid of it.

PAP: Why is it so difficult for us to “forget” wrong information?

MB: Knowledge in the head does not have a source label. Memory is not a library where I can check whether a given piece of information comes from a reliable book or from gossip. It is a network of interconnected information. So all these fake news, beliefs, rumors and stories have the same status. Once incorporated into memory, nonsense becomes an element of our understanding of the world. Pulling this information from the entire web is incredibly difficult, if not even possible. Even if we find out that Blue Monday is not true, we will not erase this concept from our brain. At most, there may be a “subtitle” saying: “this is bullshit”, but the original association remains.

I cannot forget anything voluntarily. I can reinterpret it, and I can hope that this interpreted trace will be more accessible in my memory than the original one. Convincing people that something is untrue is a bit like saying “don't think about the elephant.” This requires thinking about an elephant.

PAP: This is a very pessimistic vision. Are we defenseless against disinformation?

MB: To some extent, yes. We, people, not only do not have the tools to verify all the information that reaches us, but we are also flooded with a lot of information that has a very low status. Moreover, on the basis of this weak information that we cannot get out of our heads, we build our image of the world. The consequence of this are information bubbles, the so-called echo chambers.

PAP: So should I do this interview with you denying the existence of Blue Monday or not?

MB: Blue Monday, although it was born as a joke and a marketing trick, has been alive for 20 years and probably will not disappear. You may not write anything about Blue Monday. And then – if other journalists do it – maybe people will forget one day. Or write that it is nonsense, but then there is a risk that we will accidentally only strengthen the memory of this concept.

I would like to sow the seeds of healthy skepticism, but also make people aware of the enormous responsibility of those who communicate science and circulate information. Once nonsense has been released, it cannot be easily undone.

Interview by Ludwika Tomala (PAP)

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