Describe the negative impact of confirmation bias on problem solving and decision making.
Identify an example of confirmation bias in thinking.
Review
Select the NEXT button to continue with the Review.
1. When people are faced with a problem or decision, they often gather information to help them evaluate the situation. There are many sources of facts and opinions about almost every topic, and sometimes the information from one source contradicts information from another source. Good decision making requires gathering relevant information from accurate sources that are representative of knowledge about the topic.
Review
Select the NEXT button to continue with the Review.
2. Unfortunately, as psychologist Peter Wason has demonstrated, the search for information is weakened by confirmation bias—the tendency to look for information that matches what one already believes.
Review
Select the NEXT button to continue with the Review.
3. For example, politicians who oppose gun control legislation are more likely to read a newspaper article on the rights of individuals to bear arms than an article on the dangers of handguns in the home.
Review
Select the NEXT button to continue with the Review.
4. By restricting the amount and quality of the information considered, confirmation bias leads to poor decision making—when buying a car, investing in the stock market, or investigating a crime. For example, Indiana State Trooper David Camm was convicted of murdering his wife and children, and served 13 years in prison before a retrial acquitted him. The prosecutors were so sure Camm had committed the murders that they overlooked crucial evidence: 1) Camm was at a different location at the time of the murders, and 2) DNA from a known criminal was at the crime scene.
Practice: Demonstrating Confirmation Bias
Roll over each card to see the other side. After all the cards are turned over, select the “Decision task” button to continue.
Where do we look for information that will help us make a decision? How do we decide which information will be most relevant?
That is the question that was investigated by researcher Peter Wason in the 1960s. Now, we will simulate one of his experiments. You will see four cards like the ones here, each with a number on one side and a letter on the other.
Your task: Decide which cards need to be turned over to test whether a statement is True or False.
Your task: Decide which cards need to be turned over to test whether the statement below is True or False.
Think about this problem for a few moments and plan your strategy. Then, select the card or cards that you think must be turned over to prove or disprove the statement. Don't select any extra cards! When finished, select the RESULTS button.
STATEMENT: If the card has an odd number on one side, it must always have a vowel on the other side.
You decided to turn the cards over in this order: .
The correct answer was Card 1 and Card 4. To confirm the rule, you must turn over Card 1 to see if there is a vowel on the back of the 3 (there is an A). However, you must also look for disconfirming evidence. For that, you must turn over Card 4 to see if there is an odd number on the reverse side (there is a 7). Because Card 4 breaks the rule, your task is finished.
Most people turn over Card 2, which gives them no useful information, because the statement doesn't say, "If the card has a vowel on one side, it must have an odd number on the other side." Turning over Card 2 (to find a 5) simply confirms their expectations without testing the rule. Peter Wason found that less than 10 percent of the people he tested made the correct decisions. This demonstrates the power of confirmation bias to interfere with our search strategies.
STATEMENT: If the card has an odd number on one side, it must always have a vowel on the other side.
Quiz
Drag the padlock to the gray area in front of the scenario that illustrates the principle of confirmation bias. When you have placed the padlock, select the CHECK ANSWER button.
