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The Incentives Lab
HBT-COG-0100 · Dimension COG · Cognition

Birthday-Number Effect

Subconscious preference for numbers (and letters) that appear in our own name or birthday.

Social·Mental Model·Grade B·draft· enriching…

Scientific Definition

Subconscious preference for numbers (and letters) that appear in our own name or birthday.

Plain-English Definition

Subconscious preference for numbers (and letters) that appear in our own name or birthday.

Feynman Explanation

Implicit egotism, hiding in plain sight.

Core Principle

Subconscious preference for numbers (and letters) that appear in our own name or birthday.

Mechanisms

Psychological

Pending editorial review.

Behavioral Economic

Subconscious preference for numbers (and letters) that appear in our own name or birthday.

Neurological

Pending editorial review.

Evolutionary

Pending editorial review.

Sociological

Pending editorial review.

Computational

Pending editorial review.

Systems

Tiny biases compound in high-volume decisions like hiring or pricing.

Inputs (Triggers)

Pending editorial review.

Outputs (Behaviors)

Pending editorial review.

Behavioral Signature

Implicit egotism, hiding in plain sight.

Examples

Everyday
  • Investors mildly preferring tickers that share initials with them.
Modern (Organizational)
  • Tiny biases compound in high-volume decisions like hiring or pricing.
Historical

Pending editorial review.

Famous Experiments

Pending editorial review.

Design Principles

  • Strip identifying numbers from option sets when possible.

Measurement Approaches

Pending editorial review.

Evidence

Evidence Grade
B (A strongest → E speculative)
Replication
★★★☆☆
Intervention Confidence
3 / 5
Consensus
Pending editorial review (HBT v1.0 auto-seed).
Limitations
Pending editorial review (HBT v1.0 auto-seed).
Open Research Questions

Pending editorial review.

Primary References

Pending editorial review.

Signature Section

The Perverse Incentive Lens™

How this behavior is exploited — and how to redesign around it.

Exploitation
Tiny biases compound in high-volume decisions like hiring or pricing.
Amplifying Incentives
Tiny biases compound in high-volume decisions like hiring or pricing.
Org Failure Modes
Tiny biases compound in high-volume decisions like hiring or pricing.
Societal Failure Modes
Pending editorial review (HBT v1.0 auto-seed).
Ethical Considerations
Pending editorial review (HBT v1.0 auto-seed).
Redesign Strategies
Strip identifying numbers from option sets when possible.
Diagnostic Questions
  • Strip identifying numbers from option sets when possible.
Warning Signs

Pending editorial review.

Red Flags

Pending editorial review.

Intervention Playbook
Individual
Strip identifying numbers from option sets when possible.
Team
Pending editorial review (HBT v1.0 auto-seed).
Organization
Pending editorial review (HBT v1.0 auto-seed).
Policy
Pending editorial review (HBT v1.0 auto-seed).
AI Implications
Detection
Pending editorial review (HBT v1.0 auto-seed).
Measurement
Pending editorial review (HBT v1.0 auto-seed).
Mitigation
Pending editorial review (HBT v1.0 auto-seed).
Responsible Use
Pending editorial review (HBT v1.0 auto-seed).

Interactive Mini Network

Click any neighbor to re-center the graph and follow the threads of connection.

HBT-COG-0100 · COG
Birthday-Number Effect
BEAPAbilene ParadoxADActon's DictumABActor-Observer BiasALAffinity / Liking BiasAlAltruismAsAstroturfingAPAttitude PolarizationABAttribution BiasBEBarnum EffectBJBecause Justification

Knowledge Graph Neighbors

Version History

v1.1.0 · 2026-06-28Initial auto-seed from corpus.