AI Bias
AI bias and fairness failures in agent decision-making, from training data to output
25 patterns
AI bias and fairness failures in agent decision-making, from training data to output. We've tracked 25 distinct AI Bias patterns across production AI agent deployments — most commonly in Healthcare, Financial Services, Accuracy systems.
Each pattern below documents the specific failure mode, why it happens, and how teams have mitigated it in practice — use this page as a reference when building guardrails, writing evals, or debugging an agent that's already misbehaving in this way.
Accent and Dialect Bias
ASR Performs Significantly Worse on Non-Standard Accents
Age Bias in Symptom Interpretation
Model Misinterprets Symptoms Differently Based on Patient Age; Younger Patients Undertreated, Older Patients Overtreated
Algorithmic Discrimination
AI System Systematically Discriminates Against Protected Groups
Anchoring Bias on First Diagnosis
Agent Fixates on the First Plausible Diagnosis Suggested Early in the Conversation and Discounts Later Contradictory Evidence
Best-Case Projection Bias
Sales forecasting model uses deal probability from salesperson input, which is inherently optimistic; projects deals that salesperson hopes will close rather than actual likelihood
Bias Amplification
Agent Amplifies and Reinforces User Biases
Confirmation Bias from Prior Clinical Notes
Agent Anchors on a Prior Visit's Diagnosis and Discounts New Evidence Contradicting It
AI Agent Consensus Illusion: Causes and Fixes
Agents appear to agree, but only because they were all seeded from the same flawed context or bias -- not because they independently verified the answer.
Demographic Bias in Diagnosis & Treatment Recommendations
Model Biased Toward/Against Certain Demographics (Race, Gender, Age); Different Accuracy for Different Groups
Look-Ahead Bias in Backtests
Model Uses Future Information in Backtest That Wouldn't Be Available in Real-Time Trading
Missing Data Mishandling in Financial Models
Model Handles Missing Data Incorrectly (Mean Imputation, Deletion); Introduces Bias or Information Loss
Model Context Length Behavior Change
As an agent's conversation or retrieved context grows toward the model's context window limit, the model's behavior shifts in ways that are never announced: recall of early-turn facts degrades, instruction-following becomes less reliable, and the model increasingly favors recently-seen tokens over earlier ones ("recency bias"). Because the API returns a normal, well-formed response at every context length, the agent has no signal that it just crossed into a degraded-quality regime.
Model Fairness Bias
The underlying model exhibits systematic differences in its outputs correlated with demographic or protected attributes — name-implied ethnicity, gender-coded pronouns, geography, or dialect — that leak into agent decisions the model wasn't explicitly asked to make on that basis. Because the bias is statistical rather than an explicit rule, it survives even when the agent's prompt contains no discriminatory instruction, and it recurs consistently enough to produce a measurable disparate pattern across many decisions.
Positional Bias Omits Mid-Document Admission in Deposition Summary
Agent Summarizing a Long Deposition Transcript or Produced Document Systematically Under-Weights Content in the Middle of the Document, Omitting a Material Admission That Was Fully Within the Model's Context Window and Correctly Classified as Relevant
Recency Bias in Portfolio Recommendations
Model Overweights Recent Performance; Recommends Assets That Performed Well Recently but Are Mean-Reverting
Resume Keyword Matching Bias
AI resume screener uses exact keyword matching; rejects qualified candidates with industry synonyms or relevant but non-exact terminology (e.g., "web development" vs "frontend engineering")
Resume Keyword Overfit Bias
Candidate-Screening Agent Over-Weights Surface Keyword Matches Against the Job Description, Systematically Filtering Out Qualified Candidates Who Describe Equivalent Experience Differently
Salience Bias
Model Overemphasizes Visually Salient Features, Ignoring Context
Self-Verification Bias
Same model judges its own flawed output.
Spatial Attention Bias
Model Fixates on Image Center or Edges; Misses Objects in Peripheral Regions
Survivorship Bias in Training Data
Model Trained Only on Survived Assets; Ignores Assets That Failed or Were Delisted
Symptom Attribution Bias (Wrong Diagnosis Due to Anchoring)
Model Anchors on Initial Symptom; Misses True Diagnosis Because Anchored to Wrong Hypothesis
Training Data Leakage & Memorization
Model Hallucinates Training Data Artifacts, Overfitting to Dataset Biases
User Feedback Bias
The mechanism used to collect quality signal — thumbs-up/down buttons, post-chat surveys, star ratings — is only used by a non-representative subset of users, typically those with strongly positive or strongly negative experiences, while the much larger group with a mediocre-but-tolerable experience stays silent. Teams then treat the collected feedback as representative of overall quality, when it's actually a bimodal sample that systematically misses the median experience, leading to miscalibrated confidence in how the agent is actually performing.