Decision Fatigue is decision quality degrades over the course of a day. It sits in the Biology dimension (BIO) of the Human Behavior Taxonomy™ as element HBT-BIO-0022, within the Decision family. The core principle: decision quality degrades over the course of a day. In incentive terms, it matters because it changes the payoff people perceive before they choose — which means it can be designed for, or exploited.
Scientific Definition
Decision quality degrades over the course of a day.
Plain-English Definition
Decision quality degrades over the course of a day.
Feynman Explanation
Schedule your worst decisions for after lunch. Or skip them.
Core Principle
Decision quality degrades over the course of a day.
Mechanisms
Pending editorial review.
Pending editorial review.
Decision quality degrades over the course of a day.
Pending editorial review.
Pending editorial review.
Pending editorial review.
Pending editorial review.
Inputs (Triggers)
Pending editorial review.
Outputs (Behaviors)
Pending editorial review.
Behavioral Signature
Schedule your worst decisions for after lunch. Or skip them.
Examples
- Judge parole decisions correlate with time-since-meal.
- Executive calendar design as decision quality design.
Pending editorial review.
Original analysis from The Incentives Lab — how this element behaves inside real payoff structures.
Why this element matters to incentive design
The mistake with this element is treating it as irrationality. It is almost always a rational response to a payoff nobody wrote down. The mechanism underneath it operates in the Biology dimension — what does the body contribute?. You can recognize it in the field by its signature: schedule your worst decisions for after lunch. Or skip them. Every element in the Biology dimension changes the perceived payoff of an action before the action happens, which is exactly where incentive design has leverage.
How it gets exploited
Left undesigned, executive calendar design as decision quality design. It is amplified whenever executive calendar design as decision quality design. Inside organizations that shows up as executive calendar design as decision quality design. The pattern is the same one Goodhart's Law describes: the measurable proxy attracts the effort, and the purpose behind it quietly loses funding.
How the Lab designs around it
The redesign move is to protect mornings for hard decisions. Eliminate trivial ones. Watch for it at the boundaries: handoffs, promotions, incident reviews, and budget cycles are where this element gets its power.
Famous Experiments
Pending editorial review.
Design Principles
- Protect mornings for hard decisions. Eliminate trivial ones.
Measurement Approaches
Pending editorial review.
Evidence
Pending editorial review.
Pending editorial review.
The Perverse Incentive Lens™
How this behavior is exploited — and how to redesign around it.
- Protect mornings for hard decisions. Eliminate trivial ones.
Pending editorial review.
Pending editorial review.
Interactive Mini Network
Click any neighbor to re-center the graph and follow the threads of connection.
Knowledge Graph Neighbors
Auto-linked to the rest of the Human Behavior Taxonomy by family, domain, dimension, and shared keywords.
How options are presented changes which ones get chosen.
Too many options produces worse decisions and less satisfaction.
Defaults bypass active cognition.
Two ways of thinking, both real, both useful, often mis-deployed.
Brain weights existing state heavily.
Fast intuitive vs. slow deliberative thinking.
Glucose, omega-3s, sleep, and hydration each influence decision quality.
Naming an emotion reduces its intensity.
Cumulative physiological wear from chronic stress.
Emotional override of rational processing.
Brain region tracking conflict, error, and effort.
We treat AI as more humanlike than it is.
Where Decision Fatigue is cited in the corpus
Essays, field guides, and diagnostics from The Incentives Lab that apply this element.
Questions about Decision Fatigue
- What is Decision Fatigue?
- Decision Fatigue is decision quality degrades over the course of a day. It sits in the Biology dimension (BIO) of the Human Behavior Taxonomy™ as element HBT-BIO-0022, within the Decision family. The core principle: decision quality degrades over the course of a day. In incentive terms, it matters because it changes the payoff people perceive before they choose — which means it can be designed for, or exploited.
- What is an example of Decision Fatigue?
- Executive calendar design as decision quality design. The Incentives Lab catalogs everyday, organizational, and historical instances of this element on its Human Behavior Taxonomy™ page (HBT-BIO-0022).
- How is Decision Fatigue exploited?
- Executive calendar design as decision quality design.
- How do you design around Decision Fatigue?
- Protect mornings for hard decisions. Eliminate trivial ones.
- Which behavioral dimension does Decision Fatigue belong to?
- Decision Fatigue is classified in the Biology dimension (BIO) of the Human Behavior Taxonomy™, family "Decision", class "Neural Mechanism". Its permanent identifier is HBT-BIO-0022 and its evidence grade is B.