Glossary
Cognitive bias
What is a Cognitive Bias?
A cognitive bias is a systematic pattern in judgment that departs from a specified standard, such as a probability rule. Identifying a bias requires a clear task and comparison standard. Its size and prevalence can vary across people and contexts.
How it works
Some biases arise from using mental shortcuts, or heuristics, that work well in one setting and poorly in another. A bias label does not establish a single cause, an evolutionary explanation, or a tendency shared equally by everyone.
Tversky and Kahneman’s foundational paper gives task-specific examples. Research on heuristic decision making also shows why performance must be judged in context.
Cognitive Bias Example: Hiring
Imagine a hiring manager who gives candidates extra credit for attending the same university, despite equal job-relevant evidence. The shared affiliation is influencing the judgment beyond that evidence. Believing oneself objective does not establish that the comparison is fair.
Why it matters
A bias can help describe a specific error. A long list of labels is not a diagnosis of why a customer, employee, or voter behaved as they did. Start with the task, evidence, and comparison standard; then ask whether the proposed explanation survives testing.