Confirmation bias is where you notice facts that support a belief of yours while tending to overlook those that go against it. It is a logical fallacy: you should consider both kinds of facts. Despite that, it is a extremely common mistake people make. It is why stereotypes seem true to those who hold them.
Before I knew what it was called, I called it the Texas Cowboy Hat Effect. Texans are stereotyped as wearing cowboy hats even though few of them do. Yet if you drove across Texas you would remember the few who did wear cowboy hats and forget the many who did not. That is confirmation bias.
In science more progress is made by looking at the facts that do not quite fit the ruling ideas than by looking at those that do. Yet this is almost always done by newcomers to the field – partly because the old-timers do not take those facts seriously due to confirmation bias.
Confirmation bias has been shown by a ton of studies.
In one American study nine-year-old schoolchildren were given a one-on-one placement test. Those who did not watch the test being given thought whites would do 3% better. But those who watched reported that whites did 12% better. True, 80% of those onlookers were white or Asian, but surely no one who sees something with his own eyes is going to be fooled by whatever stereotypes he might hold. Right?
Wrong: as it turns out whites did better not by 3% or by 12% but by 0%! The thing was staged: the nine-year-olds were secretly being fed right and wrong answers so that they all got the same score.
The onlookers were fooled by their stereotypes. Because of confirmation bias they tended to remember when blacks gave wrong answers and when whites gave right ones. So even though blacks did just as well as whites, it seemed like they did worse!
Confirmation bias is why those who believe in stereotypes say they are true. Even some who know plenty of blacks will still believe the stereotypes about them – even if they are black themselves! The few cases that confirm a stereotype are given more weight in their minds than the many cases that do not.
In America stereotypes against blacks are supported by more than just confirmation bias. There is the self-interest of whites and the constant stream of racist messages. There is also out-group homogeneity bias, the idea that people in an out-group are pretty much all the same. That is why whites say they are individuals but then reduce 40 millions blacks to a half dozen Hollywood stereotypes. Or talk about black culture but say there is no such thing as white culture.
By using an MRI machine we now know which part of the brain confirmation bias takes place in: a part that deals not with thought but with feelings! It causes you to discount or overlook facts that go against dearly held beliefs, often without you even knowing it.
Thanks to commenter Jasmin for her help with this post. All mistakes, of course, are mine alone.
- whites are individuals
- Thomas Kuhn – on how science progresses
- Zora Neale Hurston: What White Publishers Won’t Print – Hurston also argues that whites think stereotypes are true to life.