You're not as rational as you think

We all succumb to cognitive biases. The sooner we admit it, the better.

Raise your hand if you think that your beliefs and choices are rational. Me too! In reality, none of us are perfectly data-driven (even yours truly). Our judgment and choices are distorted by cognitive biases - predictable patterns in the way humans reason. These hard-wired biases can mislead us in many areas of our lives, from health, to investing, to parenting and more. It pays to know what they are and learn to catch yourself in the act - the sooner the better!

Cognitive biases are “systematic cognitive dispositions or inclinations in human thinking and reasoning that often do not comply with the tenets of logic, probability reasoning, and plausibility.” (Encyclopedia of Behavioral Neuroscience, 2022)

I remember learning about cognitive biases back in Psych 101, and my mind was blown. As someone who prides herself on thinking logically, I was initially appalled by the suggestion that I wasn’t perfectly rational. Before long, I realized that I was just as guilty as everyone of cognitive biases. I’m now grateful to have these biases on my radar, so that I can actively watch for them.

A recent scientific review describes 221 cognitive biases and 11 countermeasures. It’s beyond the scope of this review to cover this vast territory, but I wanted to give you a flavour for cognitive biases by sharing a few of my favourites - those I commonly encounter and police in myself:

• Confirmation bias is when we pay attention to information that confirms our beliefs and ignore information that conflicts with them. The example that sticks in my head from my Psych 101 class involves bad drivers. If we believe that a certain type of person (race, sex, hair colour) is a bad driver, we will make a mental note of every bad driver that fits our stereotype, but conveniently ignore all the good drivers with the same characteristics.

  • Note to self: Be extra critical of information that confirms your beliefs.

• The framing effect refers to the fact that people respond differently to the same information depending on how it’s presented or “framed”. Consider how you feel about a diagnostic test that it detects 90% of cases (positive framing) compared to a test that misses 10% of cases (negative framing).

  • Note to self: Make a point of viewing new information through both positive and negative frames.

• The bandwagon effect is when we adopt beliefs, attitudes or behaviours just because others around us are doing so. Jumping on a skinny-jeans bandwagon is harmless, but other bandwagons can be seriously harmful (e.g. a vaccine hesitancy bandwagon). It pays to consciously take a data-driven approach when it comes to health.

  • Note to self: Notice when you’re making a choice because of those around you. Is it time to check with evidence-based choices?

• Anchoring bias refers to our tendency to rely more heavily on the first information that we receive on a given topic - and less attention to information that we receive later (even if it’s more scientifically vetted!). For example, if you heard that kids who watch a lot of YouTube are twice as likely to be depressed (I’m making this up!), you are likely to cling tight to this estimate even if you later learn of another study that showed a different result. This bias reared its head in a big way during the pandemic, with constantly evolving data (see article).

  • Note to self: When you hear something that conflicts with your “anchor” (the first information you encountered), ask yourself: am I unfairly dismissing it? Try to prioritize the quality of the information above all.

These cognitive biases, and many others that I didn’t discuss today, can affect the way we think on a daily basis, in every area of our lives. We can’t stop these biases from rearing their head, but we can fight back. Awareness and humility are key.

Cognitive bias codex - zoom in to see them all! (Wikipedia)

Nerd Note: Cognitive biases were first described in the 1970s by Amos Tversky and Daniel Kahneman, in their seminal paper: “Judgment under Uncertainty: Heuristics and Biases” (full text here). To date, there have been over 28,000 academic articles on PubMed about cognitive biases, spanning a vast array of fields, from health, to economics, to climate change and more.

Thanks for joining me to understand why we’re not as rational as we think and what we can do about it. I’d love to hear what resonated with you as well as any fun stories you have about cognitive biases in your life.

Best,

Chana Davis @FueledbyScience

Resources

• What is cognitive bias? Types and Examples (by Simply Psychology) 

• Overview of cognitive biases (by Scribbr)

• Difference between cognitive biases and logical fallacies (by Scribbr)

• Cognitive Biases in Fact-Checking and Their Countermeasures: A Review (Soprano et al, 2024)

• Mistakes Were Made but Not by Me (book by Carol Tavris and Elliot Aronson) 

Related articles by Those Nerdy Girls

• Confirmation bias (by Those Nerdy Girls, Amanda Simanek)

• Framing effect (by Those Nerdy Girls, Sarah Coles)

• Bandwagon effect (by Those Nerdy Girls, Sarah Coles)

• Check out #dataliteracy for other related posts from TNG