We like to think we’re rational human beings.
In fact, we are prone to hundreds of proven biases that cause us to think and act irrationally, and even thinking we’re rational despite evidence of irrationality in others is known as blind spot bias.
The study of how often human beings do irrational things was enough for psychologists Daniel Kahneman to win the Nobel Prize in Economics, and it opened the rapidly expanding field of behavioral economics. Similar insights are also reshaping everything from marketing to criminology.
Hoping to clue you — and ourselves — into the biases that frame our decisions, we’ve collected a long list of the most notable ones.
People are overreliant on the first piece of information they hear.
In a salary negotiation, for instance, whoever makes the first offer establishes a range of reasonable possibilities in each person’s mind. Any counteroffer will naturally react to or be anchored by that opening offer.
“Most people come with the very strong belief they should never make an opening offer,” says Leigh Thompson, a professor at Northwestern University’s Kellogg School of Management. “Our research and lots of corroborating research shows that’s completely backwards. The guy or gal who makes a first offer is better off.”
We tend to listen only to the information that confirms our preconceptions — one of the many reasons it’s so hard to have an intelligent conversation about climate change.
A cousin of confirmation bias, here our expectations unconsciously influence how we perceive an outcome. Researchers looking for a certain result in an experiment, for example, may inadvertently manipulate or interpret the results to reveal their expectations. That’s why the “double-blind” experimental design was created for the field of scientific research.
Bias blind spots
Failing to recognize your cognitive biases is a bias in itself.
Notably, Princeton psychologist Emily Pronin has found that “individuals see the existence and operation of cognitive and motivational biases much more in others than in themselves.”
This is the tendency to see patterns in random events. It is central to various gambling fallacies, like the idea that red is more or less likely to turn up on a roulette table after a string of reds.