Overview
The Monkey Business Illusion demonstrates selective attention and inattentional blindness through a basketball passing task that reveals how focused attention causes viewers to miss unexpected events.
The Experiment Setup
- Participants watch players in white and black shirts passing a basketball
- Primary task: count how many times white team players pass the ball
- Correct answer is 16 passes
- Multiple unexpected events occur during the video
- Experiment designed by Daniel S. Simons
Results & Findings
| Event Type | Description | Detection Rate |
|---|
| Primary Task | Counting white team passes | Most viewers complete accurately (16 passes) |
| Gorilla | Person in gorilla suit walks through scene | ~50% of first-time viewers miss it |
| Curtain Color | Background curtain changes color | Frequently missed even by those who spot gorilla |
| Player Departure | Black team member leaves the game | Frequently missed even by those who spot gorilla |
- First-time viewers unaware of the gorilla miss it about half the time
- Viewers who know about the gorilla typically spot it
- Even gorilla-aware viewers often miss the curtain color change and player leaving
The Phenomenon Explained
- Demonstrates the concept of inattentional blindness
- Focused attention on one task reduces awareness of other stimuli
- When actively searching for one unexpected element, others remain unnoticed
- Shows limitations of human visual attention and perception
Key Terms & Definitions
- Monkey Business Illusion: cognitive experiment revealing selective attention failures through unexpected events during a counting task
- Inattentional Blindness: failure to notice visible but unexpected stimuli when attention is focused elsewhere
Action Items / Next Steps
- Visit theinvisiblegorilla.com for more information about this and the original gorilla experiment
- Explore additional research on selective attention and perception