0day streak
Well-established
Logical & Reasoning
Appeal to Probability
Social-cognitive biasDefinition
The logical fallacy of assuming that because something is possible or probable, it is therefore certain or inevitable.
Why it happens
Our brains struggle with gradations of probability. It's easier to think in binary (will happen/won't happen) than to maintain nuanced probabilistic thinking.
Real-life examples
- Assuming that because there's a chance of rain, it will definitely rain — and canceling plans.
- Worrying that because accidents can happen, one will happen to you.
- Believing that because a business idea could work, it will work.
How to counter it
- Assign a rough probability (percentage) to the outcome.
- Distinguish between possible, probable, and certain.
- Make decisions based on expected value, not extreme scenarios alone.
- Ask: "What is the actual likelihood, not just the possibility?"
Quick tips
- Distinguish between possible, probable, and certain.
- Assign rough probabilities to outcomes instead of thinking in absolutes.
- Make decisions based on expected value, not worst-case or best-case alone.
- Ask: 'What is the actual likelihood, not just the possibility?'
Sources and further reading
- The Appeal to Probability Fallacy
Informal Logic