What Is… the Illusion of Causality

In this series, I dig a little deeper into the meaning of psychology-related terms. This week’s term is the illusion of causality.

The illusion of causality is a cognitive bias that makes us see causal relationships between things that aren’t actually related. This often comes into play in superstitions and pseudoscience. We naturally look for causal connections in the world around us, but our intuitive assessment of such connections isn’t always reliable. Our tendency to find these connections is so strong that we’re likely to see them even when it’s logically clear that there is no mechanism that a cause and effect relationship could be based on.

The illusion of causality isn’t dependent on intelligence or personality; it’s a natural consequence of how our brains work. A more extreme version of this may play a role in psychosis, which often involves abnormal perceptions of cause and effect relationships.

The scientific method is an approach that helps to compensate for the illusion of causality and other cognitive biases. Even most research methods can’t establish cause-and-effect relationships. They may establish correlations, but correlation alone does not imply causation.

Contingencies

When we estimate causality, we evaluate several things:

• The priority principle: Does the potential cause precede the outcome?
• The contiguity principle: Do the potential cause and outcome occur close to each other in time and space?
• The contingency principle: Does the rate at which the outcome is present vary depending on whether the potential cause is present or absent?

A contingency table, shown below, represents how potential cause A and outcome B may relate to one another.

	Outcome B present	Outcome B absent
Potential cause A present	80%	20%
Potential cause A absent	80%	20%

In the contingency table above, outcome B is not contingent on potential cause A, because the presence or absence of A makes no difference in whether outcome B is present. Outcome B is present 80% of the time, and potential cause A does sweet fuck-all to change that. This is known as a null contingency (although I kind of like sweet fuck-all contingency).

The illusion of causality happens when it looks to us like outcome B is contingent on the presence of potential cause A, when in fact it’s not.

The illusion of causality is stronger the more commonly the potential cause is present. It’s also stronger the more commonly the outcome occurs. So, in the example above where outcome B is present 80% of the time, our brains are more likely to do a cause-and-effect happy dance.

Jumping to conclusions

Research published in the journal Nature showed a link between illusions of causality and the tendency to jump to conclusions.

Previous research has shown that people who tend to have paranormal beliefs or superstitions are more vulnerable to causal illusions, and they also have a tendency to jump to conclusions.

Alternative health approaches

The popularity of alternative health approaches is often supported by illusions of causality. Homeopathy, for example, isn’t supported by scientific evidence plus it’s all kinds of out there when you explore how proponents of this pseudoscience say it works. However, if someone takes a homeopathic remedy and later starts to feel better, that can look as if it’s a cause-and-effect relationship even when it’s not.

In a paper in the journal Psychology & Health, Macfarlane and colleagues used the term “irrational health behaviours” to describe the use of alternative health remedies that fly in the face of what science shows about the remedies being either unhelpful or actually harmful. They pointed out that there can be high costs in terms of both money spent on the alternative treatments themselves and costs resulting from delays in getting evidence-based treatment. In the study they conducted, they found that presenting people with full contingency table information (in a simple form) decreased their willingness to pay for multivitamin supplements.

More pseudoscience

The illusion of causality also comes into play with other kinds of pseudoscience, like astrology. Let’s take the idea that Mercury in retrograde (an optical illusion) disturbs communication on earth (the Roman Mercury was based on the Greek god Hermes, who served as a messenger for other gods).

Things go wrong in terms of communication all the time, meaning the identified outcome is frequently present. The optical illusion of Mercury in retrograde is also pretty frequently present, happening for about 3 weeks, 3-4 times per year. Even with null contingency between the two, the frequent occurrence of both the identified potential cause and the outcome both promote the illusion of causality.

The effect of thinking in a foreign language

The language in which information is presented can affect a number of cognitive biases; this has been termed the foreign language effect. When people are performing tasks in a language other than their native language, they’re actually less prone to illusions of causality. This may relate to greater psychological or emotional distance from the problem, and greater abstraction or decreased emotional resonance may make it easier to evaluate contingencies.

Another possibility is that having information presented in a foreign language decreases processing fluency, which may lead to a more deliberate and analytical manner of processing of information rather than an intuitive manner.

Managing illusions of causality

Humans are prone to the illusion of causality; it’s just the way our brains work. Avoiding it isn’t possible, but it can be useful to recognize that it does exist and that science offers ways to gather data to counter those illusions. I think one of the downsides of the anti-science bias that seems to be fairly common these days is that it’s likely to strengthen people’s beliefs in causal illusions. Having a scientific background doesn’t stop the illusion of causality, but it can serve as a reminder to look for more objective information.

Do causal illusions sound like something that you may be seeing when you interpret the world around you?

References

• Díaz-Lago, M., & Matute, H. (2019). Thinking in a Foreign language reduces the causality bias. Quarterly Journal of Experimental Psychology, 72(1), 41-51.
• MacFarlane, D., Hurlstone, M. J., & Ecker, U. K. (2018). Reducing demand for ineffective health remedies: Overcoming the illusion of causality. Psychology & Health, 33(12), 1472-1489.
• Matute, H., Blanco, F., Yarritu, I., Díaz-Lago, M., Vadillo, M. A., & Barberia, I. (2015). Illusions of causality: how they bias our everyday thinking and how they could be reduced. Frontiers in Psychology, 6, 888.
• Moreno-Fernández, M. M., Blanco, F., & Matute, H. (2021). The tendency to stop collecting information is linked to illusions of causality. Scientific Reports, 11(1), 1-15.