What is Cognitive Bias?
Cognitive bias is a systematic thinking error that happens when our brain tries to simplify how we process information. Because our brains receive huge amounts of information every day, we often rely on mental shortcuts to make quick decisions.
These shortcuts are helpful, but they can also lead us to misjudge situations, ignore important facts, or make irrational decisions.
Example of Cognitive Bias
For example, imagine you see many posts on social media showing people becoming successful entrepreneurs or making huge profits from cryptocurrency.
After seeing these stories repeatedly, you might start believing that becoming rich through business or crypto is very common.
In reality, these stories often highlight the few successes, while many failures are rarely shared online. Your brain tends to remember the most striking stories, which can distort your perception of how common success really is.
Why do you need to understand these biases?
Cognitive biases affect many areas of life, including money decisions, career choices, relationships, and even how we judge other people. Understanding them can help us think more clearly and avoid common mental traps.
Below are 10 common cognitive bias traps that influence how people think and make decisions. 
TLDR:
Ten (10) common Cognitive Bias (认知偏差):
1. Survivorship Bias（幸存者偏差）
2. Sunk Cost Fallacy（沉没成本谬误）
3. Confirmation Bias（确认偏差）
4. Anchoring Effect（锚定效应）
5. Framing Effect（框架效应）
6. Availability Heuristic（可得性偏差）
7. Dunning–Kruger Effect（达克效应）
8. Belief in a Just World (BJW)（公正世界假设）
9. Bandwagon Effect（从众效应）
10. Self-Serving Bias（自利归因偏差）
1. Survivorship Bias
Survivorship bias happens when we only look at the successful examples and ignore all the failures that disappeared.
Because of this, we might think something is easier or more effective than it actually is.
Example:
You see many stories about successful startup founders like Elon Musk or Mark Zuckerberg, and think starting a company is a great path to success.
But we rarely hear about the thousands of startups that failed. Looking only at survivors gives a misleading picture.
2. Sunk Cost Fallacy
This happens when people continue doing something just because they have already invested time, money, or effort, even when it’s no longer a good decision.
Example:
You bought a movie ticket, but the movie is terrible after 20 minutes. Instead of leaving, you stay because you think:
“I already paid for it.”
But the money is already gone. Staying doesn’t bring it back.
3. Confirmation Bias
People tend to seek out information that supports what they already believe and ignore information that contradicts it.
Example:
Someone believes that cryptocurrency is always a scam.
They will:
Read news about crypto fraud or crypto scam
Share stories of people losing money
But they might ignore positive developments or successful projects.
4. Anchoring Effect
The first number or piece of information we see becomes an “anchor” that influences our later judgment.
Example:
A jacket is labeled:
“Was $200 — Now $90”
Even if $90 is still expensive, the $200 anchor makes the discount look more attractive.
Retailers often use this trick in pricing.
5. Framing Effect
People make different decisions depending on how information is presented, even when the facts are the same.
Example:
Two ways to describe the same medical treatment:
“This treatment has a 90% success rate.”
“This treatment has a 10% failure rate.”
Both statements describe the same outcome; most people feel more confident about the first one. This is an example of the Framing Effect.
6. Availability Heuristic
People judge how common something is based on how easily examples come to mind.
If we hear about something often, we think it happens a lot.
Example:
After seeing several news stories about plane crashes, someone might think flying is very dangerous.
In reality, flying is much safer than driving, but dramatic events are easier to remember.
7. Dunning–Kruger Effect
People with low knowledge or skill often overestimate their ability, because they don’t know enough to recognize their mistakes.
Meanwhile, experts may underestimate themselves.
Example:
A beginner learns a little about investing and suddenly believes they can beat the market easily.
But experienced investors know that investing is complex and risky.
8. Belief in a Just World (BJW)
People want to believe that the world is fair, where good actions lead to rewards and bad actions lead to punishment.
Because of this, people sometimes assume victims must have done something wrong.
Example:
When someone loses their job, others might say:
“They must not have worked hard enough.”
Even though layoffs often happen due to economic conditions, not merely personal failure.
9. Bandwagon Effect
People tend to follow what many others are doing, simply because it appears popular.
Example:
A product on an e-commerce site shows:
“10,000 people bought this item”
Many customers will buy it too because they assume:
“If everyone is buying it, it must be good.”
This is why social proof is widely used in marketing.
10. Self-Serving Bias
People tend to attribute success to their own ability, but blame failures on external factors.
Example:
If a student gets a good exam result, they might say:
“I’m smart.”
If they get a bad result, they might say:
“The exam was unfair.”
This bias helps protect self-esteem.
In politics, self-serving bias can also appear in how politicians explain success and failure. For example, when policies succeed, political leaders may credit their own leadership or strategy.
But when problems occur, they may blame opposing parties or external factors instead. In Malaysia, political debates sometimes include phrases like “ini semua salah DAP” (“this is all DAP’s fault”), where responsibility is shifted to another party rather than acknowledging internal mistakes.
Blaming others can be an easier way to protect one’s reputation and gain political support.