A driver follows the GPS onto a closed road despite the barrier in front of them. A loan officer approves every application the scoring tool flags green without reading the file. A developer merges AI-written code because the tests passed and the explanation sounded confident. Each is automation bias: the system’s answer gets more trust than the evidence supports, and errors slip past the person who was meant to catch them.
Research on clinical decision support and aviation found the pattern long before chatbots. It includes errors of commission, following a wrong suggestion, and errors of omission, missing a problem because the system didn’t flag it. It tends to get worse when people are busy, when the system is usually right, and when its output looks authoritative.
That matters for any plan that relies on a person reviewing AI output. A human-in-the-loop step only adds safety if the reviewer has the time, information and authority to disagree. The EU AI Act names the risk directly: Article 14 requires that people overseeing high-risk AI systems be able to stay aware of automation bias and to override or ignore the system. Practical countermeasures include showing sources and confidence, asking reviewers to decide before seeing the AI’s suggestion in high-stakes cases, auditing a sample of approved outputs, and tracking how often reviewers actually change anything. Automation bias is a human-factors problem, distinct from bias in a model’s training data, such as selection bias.
Sources
- Goddard, Roudsari and Wyatt: Automation bias: a systematic review of frequency, effect mediators, and mitigators (JAMIA, 2012) — Defines automation bias as the tendency to over-rely on automation and reviews evidence from clinical decision support and other fields; checked October 24, 2026.
- EU AI Act, Article 14: Human oversight — Requires that people overseeing high-risk AI systems be enabled to remain aware of the tendency to over-rely on the system's output, which the Act calls automation bias; checked October 24, 2026.
- Google Machine Learning Crash Course: Types of bias — Lists automation bias among the human biases that affect machine learning systems, with definitions and examples; checked October 24, 2026.