Ego Depletion Slides THE EGO DEPLETION
EXPERIMENT
Willpower, Fatigue, and Decision Making
AP/Undergraduate Psychology
Learning Objectives
01
Define Ego Depletion and identify its core assumptions regarding cognitive resources.
02
Analyze the relationship between decision fatigue and high-stakes outcomes (e.g., the Parole Study).
03
Apply experimental design principles to construct a study measuring decision fatigue.
Warm-Up: The Stroop Test
THE CHALLENGE:
Say the COLOR of the word as quickly as you can.
1
Focus
2
Speak
3
Resist
BLUE
GREEN
RED
YELLOW
ORANGE
PURPLE
BLUE
GREEN
YELLOW
RED
BLUE
PURPLE
GREEN
ORANGE
YELLOW
BLUE
Watch: Decision Fatigue
Embedded media
Pay attention to the Parole Study findings.
5:16 mins
Ego
Depletion
The theory that willpower is a limited mental resource that functions like a battery or a muscle.
"Cognitive Exhaustion"
"Daily Threshold"
The Parole Study (2011)
Researchers followed judges deciding on parole. The biggest variable in the decision?
TIME OF DAY
Morning cases = More favorable rulings
What Drains the Battery?
Frequency
Making many small choices in a row.
Complexity
High-stakes decisions with many outcomes.
Novelty
Choices in unfamiliar situations.
Fighting Decision Fatigue
Reduce Frequency: Create routines to automate trivial choices.
Advise a Friend: Gain psychological distance to lower cognitive load.
Don't Sweat Small Stuff: Recognize low-stakes vs. high-stakes.
Design Your Study
Duration: 30 Minutes
The Prompt
In groups, design a psychological experiment to test decision fatigue in a school setting.
Must target a specific school population.
Must involve a fatigue-inducing task.
Must have measurable quality metrics.
Key Questions
How do you measure "fatigue"?
What is your IV and DV?
What is the "Control" group?
The Replication Crisis
Ego depletion is one of the most famous theories currently facing the Replication Crisis.
Criticisms:
Publication bias (favoring "exciting" results).
Small sample sizes in early studies.
Inconsistent definitions of "fatigue."
"Is willpower really a muscle, or just a belief?"
Recent meta-analyses suggest that belief in willpower might be more important than actual biological limits.
Decision Fatigue Worksheet THE EGO DEPLETION EXPERIMENT
Experimental Design Challenge
Name:
Date:
Group Members: _________________________
Time: 30 Minutes
Lab Focus: Cognitive Psychology
Mission Objective
According to the Ego Depletion Theory, making decisions uses up a limited resource of mental energy. Once this battery is low, people experience decision fatigue, leading to impulsivity or a tendency to take the "easiest" path rather than the "best" path.
Your Task: Design a controlled experiment to test decision fatigue in a real-world school setting.
Recall: The Variables
IV: Frequency/Complexity
DV: Decision Quality
Potential Confounds: Hunger, Sleep
Step 1: The Research Question & Hypothesis
Research Question
Hypothesis (If/Then/Because)
Step 2: Operational Definitions
Independent Variable (The Fatigue Induction)
How will you make one group "exhausted"? (e.g., 50 trivial choices vs 0 choices)
Dependent Variable (The Measurement)
How will you measure "quality"? (e.g., math accuracy, impulse control test)
Experimental Groups
EXPERIMENTAL GROUP:
CONTROL GROUP:
Step 3: Procedure Sketch
Briefly describe the 5-step process from participant arrival to data collection.
1
2
3
4
5
Step 4: Ethics & Extraneous Variables
Confounds (Extraneous Variables)
What factors outside your IV might influence the results?
Debriefing & Ethics
How will you ensure participants are not overly stressed?
Critical Analysis
1. How does your experiment address the "Belief vs. Biology" debate? (Does it matter if the participant believes willpower is limited?)
2. If you found "no effect" (null results), how would this connect to the Replication Crisis in psychology?
Ego Depletion Teacher Guide TEACHER GUIDE
The Ego Depletion Experiment
Subject
AP Psychology / Intro Psych
Concept Summary
This lesson introduces students to Ego Depletion, the psychological theory that willpower and cognitive control are finite resources. Students will observe the real-world consequences of decision fatigue through a judicial case study and apply experimental methodology to design their own fatigue tests. Crucially, the lesson ends with a discussion on the Replication Crisis, teaching students that psychological science is a self-correcting, evolving field.
Core Psychological Standards (APA/AP):
Experimental Method & Scientific Inquiry
Motivation & Emotion (Willpower)
Social Psychology (Situational Factors in Rulings)
Lesson Flow
05m Stroop Test (Warm-up)
10m Video & Key Concepts
30m Design Challenge
10m Extension: Replication
Part 1: The Stroop Test (Inducing Fatigue)
Execution: Use the slide provided. Tell students they have 20 seconds to get through the grid. Most will struggle and feel a "pull" toward reading the text.
Discussion Prompt: "Why was that hard? What was your brain fighting against?" (Focus on the effort required to suppress the dominant response—reading—and how that effort 'feels' like physical work.)
Part 2: Video & The Parole Study
Video Link: https://www.youtube.com/watch?v=X7j8F16eSqs
Critical Pause Point (0:52): Ask students why time of day mattered before the video reveals it. Many will guess hunger; explain that while hunger plays a role (glucose), the sheer number of decisions is the variable being studied.
Key Vocabulary to Emphasize:
Part 3: The Design Challenge
Facilitation: Group students (3-4). Distribute the "Decision Fatigue Worksheet".
Common Pitfalls to Watch For:
The Replication Crisis Extension
This is the "Hidden Lesson." In 2016, a massive multi-lab replication project failed to find a significant effect for ego depletion.
