Confirmation Bias, explained.
Confirmation bias is favoring information or tests that support an existing belief while giving less attention to evidence that could challenge it.
Why it happens
A result compatible with your theory may also be compatible with several rivals. A useful test separates the explanations. In the sequence game, examples that fit a narrower guessed rule can all fit a broader hidden rule too.
Confirming examples can fit several explanations at once. A useful test is one on which competing hypotheses disagree.
Read the result
Try a sequence your theory rejects, not just another one it accepts. The feedback becomes informative when competing rules predict different answers. A single positive test rarely identifies the only possible rule.
A worked example
Guessing a sequence rule
You see 2, 4, 6 and guess that the rule is increasing even numbers.
Testing 8, 10, 12 supports that guess but also fits many broader rules. Testing 3, 5, 9 distinguishes the even-number guess from a strictly increasing rule.
Design a test that could make you revise your explanation, then use the result to compare alternatives.
OPTIONAL DEEPER DETAILGo deeper: inside the model
Inside this model
The hidden rule accepts any three strictly increasing numbers. Each submitted triple receives truthful yes/no feedback. The tally records tests and rejections; the rule can be revealed when you are ready.
Where this idea is useful
A practical use
A product team convinced that discounts cause purchases should also seek situations that could contradict that explanation, rather than collecting only successful campaigns.
A common misconception
“Finding supporting evidence proves my explanation.”
Support is useful only in relation to what other explanations would predict. Several theories can explain the same observation.
What this explanation leaves out
- This recreates the structure of a classic reasoning task, not an assessment of your personality. In real research, evidence is noisy and hypotheses may be much harder to distinguish.
Does confirmation bias mean my belief is false?
No. A correct belief can be tested poorly too. The bias concerns how evidence is sought and interpreted, not whether the initial conclusion happens to be right.
What observation would make you change your mind, and have you looked for it?
Further reading
Explore the original research or the teaching reference behind this experiment.