The `Conjunction Fallacy' is a fallacy or error in decision making where people judge that a conjunction of two possible events is more likely than one or both of the conjuncts. Here are some examples. EXAMPLE ONE: Doc went to the store and bought tofu, eggplant, broccoli, and frozen meatless lasagna. Is it more likely that Doc is a man or a man who is a vegetarian? EXAMPLE TWO: Doc has a PhD or Doc has a PhD and reads the Wall Street Journal. EXAMPLE THREE: Aaron drove to a party in South Dakota in a Rolls Royce or Aaron drove to a party in South Dakota in a Rolls Royce as is a millionaire. In each example, the former is the correct answer. CONJUNCTION FALLACY: MR. F. HAD A HEART ATTACK. Excerpt from pages 51-52 of the book The Velocity of Information: Human Thinking During Chaotic Times (2022). In 1983, world-renowned psychologists Amos Tversky and Daniel Kahneman published a ground-breaking study on intuitive human cognitive bias (cite 1). They showed that when subjects are asked the likelihood of several alternatives, including single and joint events, they often make a conjunction fallacy. That is, they rate the conjunction of two events as being more likely, or more plausible, than only one of the constituent events. They presented the following fabricated scenarios to 115 undergraduates at Stanford University and the University of British Columbia: A health survey was conducted in a representative sample of adult males in British Columbia of all ages and occupations. Mr. F. was included in the sample. He was selected by chance from a list of participants. Which of the following statements is more probable? (A) Mr. F. has had one or more heart attacks. (B) Mr. F. has had one or more heart attacks and he is over 55 years old. This seemingly transparent problem elicited a substantial proportion (58% selected option B) of conjunction errors among statistically naive respondents (cite 2). WE ARE PRONE TO BELIEVE VIVID STORIES. This example, and countless like it, reveal that we are all subject to the conjunction fallacy, where we regularly violate the laws of probability due to a vivid story. This error in decision-making happens when people judge that a conjunction of two possible events is more likely than one or both of the conjuncts. Innate human reasoning infers that the addition of more details increases the probability of two events occurring simultaneously. (It is also an explanation for why liars tend to add additional or even excessive detail to a given lie in order to predispose the recipient to accepting the lie as truth.) However, the more detailed outcome is just that, more detailed. It is not more plausible or more likely. In fact, the probability of the two events occurring together (in conjunction) is always less than or equal to the probability of either one occurring alone. In other words, a conjunction cannot be more probable than one of its constituents. CONJUNCTION FALLACY DURING THE PANDEMIC. Which of these statements might you have deemed to be most probable on March 25, 2020? (A) The governor has ordered people to stay home. (B) The governor has ordered people to stay home, and state highways are closed. Previous studies of conjunction statements imply that the majority of people presented with these statements would select B. Fortunately, conjunction bias collapses in on itself when too many conditions are stated. Most people are able to identify the mental trickery of a statement with a dozen conjunctions. It no longer makes sense from a face validity standpoint. CITATIONS: (1) Tversky, Amos and Daniel Kahneman. “Extensional Versus Intuitive Reasoning: The Conjunction Fallacy in Probability Judgment.” Psychological Review, 90 (1983): 293–315. (2) Tversky and Kahneman, Extensional Versus Intuitive Reasoning, 293–315. FOLLOW DR. PERRODIN: Twitter @SafetyPhD and subscribe to The Safety Doc YouTube channel & Apple Podcasts. SAFETY DOC WEBSITE, BLOG & BOOKS: www.safetyphd.com. The Safety Doc Podcast is hosted & produced by David P. Perrodin, PhD. This podcast and blog post represent the opinions of David P. Perrodin and his guests to the show. The content here is for informational purposes only. Please consult with your safety professional regarding the unique needs of yourself or your organization.This is episode 172 of The Safety Doc Podcast published on 03-08-2022. GET DOC’S BOOKS. Purchase the preeminent book of scholarship for an uncertain epoch from your favorite bookstore or online retailer and recommend it as a purchase for your local library! The Velocity of Information: Human Thinking During Chaotic Times (2022) by David P. Perrodin.
Purchase Dr. Perrodin’s Books:
Top Ten Questions About Working At The School For The Blind | SDP162
Life Pivot After Traumatic Brain Injury | Behind The Media Curtain | Guest Sassed1 2Many | SDP161
Why Words Matter | The Lexicon of Crisis Communication | Lost Lives and Crashes | SDP160
Entropy of Structures and Systems | The New Fire Engine Effect | SDP159
Teacher Burnout Crisis | Short-Staffed Schools Closing | 5 Ways to Solve It Right Now | SDP158
COVID Chaos | Update on Parents Suing School Districts | Special Guest Attorney Lisa Linney | SDP157
JIT Manufacturing Ceding To 3D Printing | Supply Chain Experiencing Disruptive Transition | SDP156
FBI Planning To Investigate Parents | NASB and AG Garland Memo | What You Need to Know | SDP155
School Mask Mandates and Parents Filing Lawsuits Against Schools | What You Need To Know | SDP154 | Livestream 10-12-2021
Intellectual Property for the Everyday Internet User | Lee Jarvis | SDP153 | Livestream 12-27-2020
Carl Hopf: EHS in the time of COVID | Bluetooth, PPE, and Biological Best Practices | SDP152 | Livestream 11-24-2020
New First Amendment Playbook | The Rules Have Changed | Big Tech Censorship | Livestream 11-12-2020
Rogue Birthday Episode | Election Impact on Chaos | De-Platforming Survivalists | LIvestream 11-7-2020
Failure to Regress to the Mean | Why Things Aren't Returning to Normal | Livestream 10-29-2020
Matthew Hoover | Four Waves of Chaos | Where is All the Ammunition? LIVESTREAM 9-3-2020
SDP147 | CPA Chad Elkins | Finance in Chaos | Money Behaviors of Panicked People | Livestream 8-13-2020
SDP146: Survival Expert Morgan Rogue | Subtle Signs of Chaos | Livestream 8-7-2020
SDP145: The Most Dangerous Job in the World: Alaskan Crab Boater Robert Travis | Livestream 8-3-20
Untold Stories From Former Soviet Cyclist Nikolai Razouvaev
Clay Martin | Author of Concrete Jungle: A Green Beret’s Guide to Urban Survival | LIVESTREAM 7-18-2020
Create your
podcast in
minutes
It is Free
Positive Thinking Mind
In the Great Khan’s Tent
Visualize Meditations
The Mel Robbins Podcast
The Jordan B. Peterson Podcast