Did you know that by adding a strawberry to the top of a cake you can trick people into thinking that the cake has fewer calories than it actually does? It's called a cognitive bias.

Cognitive biases are psychological deviations that prevent us from rationally processing information. Usually unconscious, this form of false logic thinking influences our judgments, perceptions, and even our memory!

The amazing thing about cognitive biases is that even knowing about them, you can't help but fall for them. Take for example the anchoring effect, used systematically during sales. If you see that a jacket was worth €299 and it's on sale for €49, you'll probably buy it... even though you know for a fact that it was never worth €299!"

If you are a marketer you probably don't consider yourself to be a psychologist. Yet, understanding how the brain works can help you persuade your audience.

So here are 50 cognitive biases that might be useful to you in Marketing, divided into 6 categories: memory, social, learning, belief, fashion and politics.

Infographic on cognitive biases inspired by Titlemax

Bias #1: Fundamental attribution error

Other people's actions reflect their character but our own may depend on context.

My neighbor chose this painting because it is naive. Me, I picked it because of the promotion.

Bias #2: Self-complacency

Our failures (unlike our successes) are not our responsibility.

My marketing campaign failed because customers didn't understand anything about what was expected of them.

Bias #3: Intragroup

We view members of our group more favorably than those who are excluded.

I have interviewed my family and unlike you, we agree: this product will be a hit!

Bias #4: The hype

Aggregation of a behavior once many other people adopt it.

It's really about time I bought that last smartphone that all my friends have.

Bias #5: Groupthink

Due to a desire for harmony in the group, we make irrational decisions.

I don't want to offend my client or my boss, so I'll make it look like a computer failure.

Bias #6: The halo effect

An individual is judged positively if he or she exhibits attributes previously judged positive.

What a handsome man, that salesman! I'm sure what he's telling me is the pure truth.

Bias #7: Moral luck

An individual receives blame/praise for an act, even if it was not totally intended.

We perform better than our competitors because we have more human values.

Bias #8: False consensus effect

Tendency to overestimate the degree of agreement that others have with us.

Everyone knows that milk is good for you.

Bias #9: Curse of knowledge

Once we learn something, we assume that everyone else knows it too.

I just saw my first webinar on SEO! What do you mean, what is it?? Ignorant!"

Bias #10: Projector effect

We overestimate the attention people pay to our behavior and appearance.

I can't wear these shoes to the webinar. Everyone will see that they are not shined!

Bias #11: Heuristic availability

Our decisions are based on current information, which we always have in mind.

I just saw an ad for X, I'll probably buy it as I walk past the shelf.

Bias #12: Identifiable victim effect

We feel more empathy when we can identify with a victim.

The professional in this ad has the same problem I do. His solution should work for me too.

Bias #13: Belief in a just world

Some events are seen as intended to punish or reward a previous act.

I got lucky this morning! It was probably because of the donation I made to the red cross.

Bias #14: Naive realism

We believe we observe reality objectively but that others observe it in a biased way.

"The enemy is stupid: he believes that we are the enemy when it is he!" (Desprosges).

Bias #15: Naive cynicism

People expect more self-centeredness from others than is actually the case.

If this brand is doing a promotion now, it's probably to rip me off afterwards.

Bias #16: Barnum Effect

Consists of giving a personal meaning to a text that can be applied to anyone.

Look, I just got an email telling me I won $100 because I am a very special customer!

Bias #17: Dunning-Kruger effect

The less qualified overestimate their skills and the more qualified underestimate them.

Advertising doesn't work on me, I've seen every episode of "Pub Culture!"

Bias #18: Anchoring effect

The first information received is used as a reference to judge subsequent ones.

This product was worth 990€ but during 24H, it is reduced to 490€ [its usual price, Editor's note]. This is a great deal.

Bias #19: Automation

We favor decisions from automated systems even if they are obviously incorrect.

My spellchecker says "supposed to" not "sensible". So that's the correct wording.

Contrary to what we think, machines are not always right.

Bias #20: Digital Amnesia

We tend to forget about easily accessible information via search engines.

This woman in this commercial is my favorite actress! Her name is...uh...wait I'm checking Google.

Bias #21: Reacting

Desire to do the opposite of what is dictated by others to prove our freedom of spirit.

You all tell me that electric is the future. So I'll keep my old diesel car.

Bias #22: Hypothesis confirmation

We tend to believe and remember information confirming our perceptions.

Do you eat meat? You're crazy, it's not good for your health. They say it everywhere.

Bias #23: Backfire effect

We refute logical evidence if it would invalidate our beliefs.

The government communicates heavily about seatbelt use in cars. Probably a hoax.

Bias #24: Third person effect

People believe that mass media influences others more than themselves.

You're really naive to believe what you're told on the news!

Bias #25: Belief bias

We primarily judge an argument based on its alignment with our beliefs.

What this ad says is probably wrong, but it clearly goes along with my beliefs. So I'm relaying it!

Bias #26: Cascading availability

The more repeated a belief is, the more plausible it is considered.

I'm not going to buy this baby potty. I hear it has razor blades in it!

Bias #27: Declinism

Belief that a society or institution is inexorably moving toward decline.

I love this product. It reminds me of that time when we still knew how to make beautiful things.

Bias #28: Status quo

We prefer things to stay the same. The change is considered a loss.

This service doesn't work every other time! Still, I'll keep it, I've gotten used to it.

Bias #29: Sunk costs

We invest in a project until time that investment can be justified.

This investment has been costing me money for 5 years. I'm not going to stop it now to gain nothing!

These costs are neither refundable nor recoverable by any other means.

Bias #30: Player Sophism

We believe that past events have an incidence on future possibilities.

It's been a year since I won anything at this game of chance. Inevitably, I'm going to win in not too long!"

Bias #31: Zero risk

We would rather have small, certain profits than larger but less certain profits.

I'm going to put all my savings in gold. It's safe, gold!

Bias #32: Framing effect

We react differently to messages depending on how they are presented to us.

81% of their customers are satisfied? Must be a good brand [that has 19% unhappy customers, Editor's note].

Bias #33: Stereotype bias

Beliefs about a group that are generalized to all members of that group.

This product references Star Wars. Therefore, it is intended for children.

Bias #34: Homogeneity effect

In contrast to the members of our group, the members of other groups look the same.

I'm not going to buy this product: it's pink, so it's for women!

Bias #35: Principle of authority

We trust and are more often influenced by the ideas of authority figures.

The gentleman in the white coat talking in this commercial tells me it's good for my health so I believe it.

Bias #36: Placebo effect

Improved health not attributable to treatment.

Since I've been eating this trace element yogurt, I feel significantly better!

Bias #37: Survivor bias

We focus on the success of a process but neglect the failures preceding that success.

The private space industry is doing very well. Look at the success of SpaceX!

Bias #38: Perception of time

We perceive time differently after trauma or considerable effort.

I don't understand anything about this commercial, it seems to go on forever!

Bias #39: Parkinson's Law of Futility

We place too much emphasis on trivial matters and avoid complex problems.

I absolutely have to get my tax problem sorted out...what's new on Netflix?

Bias #40: Zeigarnik Effect

We remember unfinished tasks more than completed ones.

Three weeks I've been going to the gym and I still don't see an effect in the mirror...

Bias #41: IKEA effect

We place more value on things that we partly created ourselves.

Can I customize my mug?! Wow!"

At The Super Agency, we are not immune to the IKEA effect.

Bias #42: Benjamin Franklin Effect

After performing a service for someone, we are convinced that they are appreciative.

I took the questionnaire from this bank. I'll be happy to buy insurance there.

Bias #43: Witness effect

The more witnesses, the less likely they are to help the victim.

This product seems dangerous to me for children and nothing is marked. Surely someone will respond!"

Bias #44: Suggestibility

We fill in the gaps in some memories with information suggested beforehand.

A two-year warranty extension as I committed to? Oh yeah, okay, if you say so.

Bias #45: False memories

We mistake our imagination for real memories.

I am twenty years old and remember Y2K perfectly.

Bias #46: Cryptomnesia

We think we are producing an original idea without remembering having read it before.

I just had a great idea! I'm going to have our meal delivered directly from our restaurant.

Bias #47: Series Illusion

Tendency to falsely perceive coincidences in random data.

An 8% reduction? Great, 8 just happens to be my lucky number. I was born on 08/08/1988!"

Bias #48: Pessimism

Tendency to overestimate the probability of getting unfavorable outcomes.

I'm sure I'll get robbed. I'll buy a security system.

Bias #49: Optimism

Tendency to overestimate the likelihood of getting favorable outcomes.

By registering on this dating site, I am sure that I will finally meet my soulmate.

Bias #50: Blind spot

We think we are impartial, unlike others.

Everyone is wrong about the quality of this product. Me, I know it's reliable. Besides, my cousin does it.

So, will you add a strawberry to your cake?