Hey all,
Welcome to Human Nature, the illustrated psychology newsletter.
We are continuing on the theme of cognitive biases. This week’s topic is the confirmation bias.
Confirmation bias
What it is: Perhaps the most ubiquitous of all cognitive biases, the confirmation bias refers to our tendency to seek out or interpret information in a way that confirms our existing beliefs. On the other hand, we tend to discount information that goes against our views.
How its was discovered: Although this phenomenon had been observed throughout history, the first experimental test of the confirmation bias was conducted in 1960 by Peter Wason.
In his experiment, Wason showed participants a sequence of numbers (2,4,6) and told them that they followed a logical rule. He then asked participants to discover what the rule is by suggesting different number sequences. The majority of participants failed as they overestimated the rule’s complexity, such as “the middle number is the average of the first and last”, when in reality the rule was simply “ascending numbers”. Moreover, they kept trying to confirm their hypothesis even after being told it was wrong.
Although this experiment was later considered to be flawed, numerous studies have lent support to the existence the confirmation bias since.
How it works: There are several explanations for the confirmation bias, but it’s generally thought to be due to a combination of cognitive and motivational factors. One explanation is that we want our beliefs to be consistent with evidence in order to protect our ego. Another is that cognitive limitations such as the availability heuristic (we think evidence that comes to mind more readily is more reliable), or our inability to focus on more than one thought (and therefore consider more than one hypothesis) at a time cause us to make errors in judgement.
Thank you for reading, see you next time!
Sources:
https://www.donchristoff.com/wp-content/uploads/2022/11/nickerson1998.pdf
https://bear.warrington.ufl.edu/brenner/mar7588/Papers/wason-qjep1960.pdf
Cognitive biases are systematic errors in thinking that we all make and that affect our judgement and behaviours. We humans like to believe we’re rational thinkers, but our brains aren’t quite wired that way. Cognitive biases are just one of the ways in which our thinking is flawed, so it’s good to be aware of them.