Confirmation Bias
When System 2 goes rogue
You may have heard of confirmation bias. Let’s say you like a certain politician1. You might give this person credit for all kinds of things they have very little control over (like the economy or a war). But if you hear that this same person took a bribe, you might be inclined to look for evidence that explains his behavior away (“he was simply following the customs of a foreign country!”).
Sports fans act this way too. Every call against my team is evidence of officiating bias. But if players for the other team complain about missed calls, they’re whiners.
Confirmation bias is not just seeing what you want to see – it's actively gathering pieces of evidence that support the conclusion you like. In the worst form of confirmation bias, our System 2, the one we didn’t want to activate in order to solve a math problem or hunt for evidence in a passage, works against us.
You might think that confirmation bias wouldn’t come up in test prep very much. After all, politics and sports are highly emotional. Does anyone care that much about math, grammar, reading, and science? Yes! Students cry tears of joy upon receiving their test scores. Middle-aged adults recount nightmares they still have about taking their tests.
The emotional current is even fairly strong during practice tests. As I mentioned in an earlier post, as much as students want high scores, they usually want two things even more: 1) They want to feel right. 2) They want to be done. If you’ve done a little work, reached a conclusion, and now see that conclusion validated in an answer, thus taking another step towards victory…it gets emotional. You don’t want to give up the answer you’ve already got (your completion trophy), and you very much want to be done.
Errors usually occur when you settle on an answer before you’ve factored in all of the relevant information. Here’s a quick math example:
If you are moving too fast, you might assume the question is asking for the missing dimension. When you see “6” as an answer choice, it will confirm the answer you have in mind, thereby locking in the wrong answer.
In the more extreme form of confirmation bias, students actually do extra work to support a bad decision. I’ll return here to my buddy Alhazen from the ISEE reading passage:
Suppose you did not really understand this paragraph the first time. To answer this question, you should really go back and read the paragraph again. But this is what often happens instead:
“I could go back…sounds like a lot of work. Let’s see if any of the answers look good. Literature? No…CAMERA! I remember that! Let’s keep that. Respect? No. Stressing? No. Okay, it’s B. But let’s double-check…Yup, there it is: “...like a primitive camera, creating a picture…”
Interestingly, if I ask students at this point why they think it’s B, they will actually invent material: “I remember it said that he built a camera.”
So, to recap: The student didn’t want to use System 2 when reading the passage the first time (reading more carefully, taking notes, taking a moment to synthesize). He didn’t want to use it when it was time to answer the question (he skipped straight to the answer instead of going back). But then, once he’d latched on to an answer, then he was willing to use System 2 to go back and support his opinion, and to use it a little more when I asked how he got that answer.
It could happen to anybody, and it does happen to everybody, in some form. But it can also be avoided. In future posts, I’ll talk more about how, but for now, I’ll highlight one key takeaway: gather information before you make your decision.
Because once you make that decision, even System 2 might not help you.
I don’t have anyone in particular in mind. You could come up with examples for almost any candidate from any party.