Have you ever heard the famous claim that our brain only uses 10% of its potential? Well as far as science knows, this is absolutely not true. At least our consciousness is very limited in nature and relies on many heuristics (mental shortcuts) to go through everyday life’s challenges. The sheer amount of information and stimuli we are exposed to is so overwhelming that this is the only way to conserve our limited processing capabilities. Unfortunately these heuristics do not always produce favourable results. Although for the most part they are very helpful, there are also quite a few situations where they lead to wrong conclusions or erroneous decisions.
This is the reason why marketing campaigns are so effective. They benefit from our processing limitations and turn those heuristics against us –  to change our behaviour in a desired way. If we were perfectly rational, we would not fall prey to such things. Unfortunately that is not the case, and while it is not possible to fight back or resist, it may be helpful to be aware of some of the heuristics that steer our mental wheels.

The availability heuristic

Which animal is more dangerous – sharks or dogs? If your initial thought was sharks, then you fell prey to the availability heuristic:

The easier it is to think of an event, the more likely it is judged to be (“if I can imagine it, it is more likely”).

Because it is much easier to think of accidents whereby sharks attacked people (simply because they are more memorable), we automatically assume that they are more dangerous than dogs. Dogs are man’s best friend, right? As it turns out, statistics show otherwise. You are far more likely to get involved in a deadly accident with a dog, as opposed to a shark. On average there are 10 persons killed by sharks every year, while the number of dog accidents is 25.000 (source). Mosquitos followed by humans are in fact the two most dangerous animals on the planet!
Another example to portrait this: are there more words starting with the letter R, or words with R as the third letter? Again, it is easier to think of many words starting with R than those with R as third letter. Therefore people are more likely to give the wrong answer – it turns out that R as the third letter is more frequent.

How can this knowledge be (ab)used? By providing information and making it more memorable (flashy ads, loud music, catchy songs, beautiful girls/boys in the background, etc.) it becomes a lot easier to recall this information. In the case of ads, this makes us choose the product they advertised far more often, when we are required to make a decision. Another example is media coverage. By repeatedly showing violent incidents involving minorities, viewers actually come to believe that minorities are more dangerous and in generally the attitude against them becomes more negative. Think of it: how many minorities do you know, who did actually hurt someone, or who did something really, really bad? The availability heuristic may play a big role as the cause of prejudice and racism.

A sub-part is the familiarity heuristic, which states that people are more likely to stick to their past, familiar choices and keep the status quo, instead of exploring novel options. Especially in situations, where somebody needs to make a choice between a large amount of options (a so called “choice overload”), people are most likely to choose something they are already familiar with. This is the reason, why there is so much bratwurst and beer at famous touristic destinations for the Germans.

The representativeness heuristic

Consider Alice: she is shy, prefers being on her own, loves reading fantasy books, does not drink alcohol, is not very sporty, and likes playing computer games. Do you think she is more likely to be single or to wear glasses and be single? If you thought she is more likely to wear glasses and be single, you fell prey to the representativeness heuristic:

The more something represents or fits into a specific group, the more likely it is to be part of the group.

The description of Alice will activate the prototype of a “nerd”. The typical nerd wears glasses and is not very popular among the other sex. Therefore the second description tends to be chosen more often over Alice simply being single. Statistically however, the chances of her only being single are far higher than her being single AND wearing glasses. The proportion of single people who wear glasses is far smaller than those who are just single. If this sounds confusing, the following picture will make it more clear.


Another example:
You toss a fair coin ten times. Which of the following results is more likely?
a) heads, heads, heads, heads, heads, heads, tails, heads, heads, heads
b) tails, heads, heads, tails, heads, tails, heads, tails, heads, tails
If you think b) is more likely, you are wrong. Usually coin tosses activate a rather random-looking prototype in our minds. Because b) looks a lot more random than a), people tend to judge it as more likely. Because the coin is fair, however, it turns out that both a) and b) have exactly the same likelihood of happening.

How is this (ab)used in daily life? Gamblers on a loosing streak are deliberately allowed to make small wins once in a while, to give them hopes. In their minds they can not keep loosing forever, and they think they will eventually get out of the loosing streak and make up for all the losses. They forget the most important rule – the house always wins. This is also called the gamblers fallacy.
Another example is that getting advice from a person with a professor or doctor title is regarded as far more credible. This is because those titles activate the prototype of smart, academic people, who are experts in their field. Consider this the next time you see a TV add, where some apparent “doctor” recommends using product X. This is known as the “authority principle“.


Anchoring occurs, when the initial information given, influences people’s decisions and estimates. For example, if you asked a group of people whether the Amazon river is longer or shorter than 1000km, they will most probably say longer. If you then let them estimate its length, they will usually come to a value close to 1000. Doing the same with another group of people, but first asking whether it is longer or shorter than 15.000km, will on average lead to estimates which are much, much higher. This is, because the initial information given (1000km vs 15.000km), although not relevant for the answer, is still being used as an anchor (starting point) for people’s estimates.
This heuristic can have an enormous impact, when it comes to negotiations and the like. Anchoring a price of a desirable product around 10.000€, as opposed to 1000€ can have tremendous effects on revenue. Therefore it is useful to know that the person in a negotiation, who first makes a proposal, usually has a big advantage, because he sets the anchor to a number in his favour.

Framing effects and prospect theory

As it turns out, our minds are set to evaluate losses much worse than equivalent gains. This means, that loosing 500€ will be perceived as much worse than the joy of winning 500€. Because of this, people are more likely to take risks to reduce their losses, as when it comes to make profit. Consider these two scenarios:

1. which would you choose?
a) a sure gain of 10.000€
b) a 50% chance of winning 20.000€ or not winning anything at all

2. which would you choose?
a) a sure loss of 10.000€
b) a 50% chance of loosing 20.000€ or not loosing anything at all

Most people tend to take the safe option a) in the first scenario. They are not willing to take unnecessary risks when it comes to gains. If however, they face loosing something, they are much more willing to take risks, thus choosing b) in the second scenario.

This can be (ab)used, by simply framing a question in terms of losses or gains. Making people aware of potential losses will make them more likely to take a risk in order to avoid them. Consider this the next time you are offered a needless insurance and reminded of all the terrible things that may happen.

The contagion heuristic

The last heuristic I would like to talk about is the contagion effect. This is pictured by people believing that properties of one object can be transferred to another object it has been in contact with. This is the reason, why you would never find toilet products, such as brushes anywhere near the food section in a store. People automatically perceive such objects to be dirty, but more importantly they also think that the dirtiness would also spread to products in close distance.
The same holds true for positive attributes. Consider this the next time you see a perfume commercial, which shows a plethora of attractive looking people using the same product.
If you are still not convinced by the effectiveness of this heuristic, think whether you would wear a perfectly looking jacket, which belonged to a serial rapist who used to torture and kill his victims.


These were just a few of the many mental shortcuts that help us navigate through different everyday situations. The human brain is by no means perfect, and knowing more about how it works can help to avoid becoming the target of manipulation strategies.

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