Irrationality Book Summary - Irrationality Book explained in key points
Listen to the Intro
00:00

Irrationality summary

Stuart Sutherland

The Enemy Within

4.3 (61 ratings)
23 mins

What is Irrationality about?

Irrationality (1991) is a guide to illogical decisions, unreasonable actions and irrational behavior as a whole. These blinks reveal how people tend to be more irrational than rational, examines several reasons why and offers solutions as to how we can become a little more logical in our decision making.

Table of Contents

    Irrationality
    summarized in 10 key ideas

    Audio & text in the Blinkist app
    Key idea 1 of 10

    Irrationality is more common than people think, and it’s the result of ignoring knowledge.

    We tend to think that human beings are deeply rational beings, and the basis for this idea can be traced back thousands of years. From Aristotle’s claim that man is a “rational animal,” to Descartes’ famous statement, “I think, therefore I am,” to Kant’s “have the courage to use your own reason,” a common belief throughout history has been that humans are fundamentally rational.

    But this might not be true after all.

    When we meet a new person, we often judge them in an instant, based solely on their looks. This is both exceedingly common and totally irrational, as people often turn out to behave very differently than they appear.

    So, clearly we’re prone to irrationality – but what does that word actually mean?

    In a nutshell, irrationality means deliberately forming conclusions that aren’t based on knowledge. So, it might be rational for a young boy to climb a tree to try to touch the moon. But the same action would be absolutely irrational if performed by an adult astronomer who knows how far away the moon is.

    Basically, the breadth of our knowledge plays a role in determining the rationality of our actions. But, while rational thinking is based on knowledge, rational conclusions can also be false. For example, people long believed that all swans were white; this was a completely rational assumption until the Australian continent was discovered, where black swans are common.

    This is an example of how insufficient or false knowledge can produce false conclusions, despite rational thinking. But false rationality is not to be confused with irrationality. Irrational thinking differs in the sense that it’s deliberate.

    Inadvertently forgetting to carry the one when doing math will produce an error – but it wouldn’t be the result of irrationality. Irrationality would be to ignore knowledge despite its ample presence, such as by thinking someone is unsuited for a job despite her résumé being a perfect fit for the requirements.

    So, making an irrational decision requires deliberate action. But why do humans do this?

    Want to see all full key ideas from Irrationality?

    Key ideas in Irrationality

    More knowledge in less time
    Read or listen
    Read or listen
    Get the key ideas from nonfiction bestsellers in minutes, not hours.
    Find your next read
    Find your next read
    Get book lists curated by experts and personalized recommendations.
    Shortcasts
    Shortcasts New
    We’ve teamed up with podcast creators to bring you key insights from podcasts.

    Best quote from Irrationality

    Everybody is irrational some of the time, and the more complex the decisions to be taken, the more irrational they are.

    —Stuart Sutherland
    example alt text

    About the Author

    Stuart Sutherland was a renowned psychologist and writer who taught at Oxford University and the University of Sussex. He is best known for his book Irrationality and a personal account of his struggle with manic depression, titled Breakdown.

    Who should read Irrationality?

    • People who think of themselves as entirely rational beings
    • Anyone who struggles to make decisions, especially rational ones

    Categories with Irrationality

    Books like Irrationality

    People ❤️ Blinkist
    Sven O.

    It's highly addictive to get core insights on personally relevant topics without repetition or triviality. Added to that the apps ability to suggest kindred interests opens up a foundation of knowledge.

    Thi Viet Quynh N.

    Great app. Good selection of book summaries you can read or listen to while commuting. Instead of scrolling through your social media news feed, this is a much better way to spend your spare time in my opinion.

    Jonathan A.

    Life changing. The concept of being able to grasp a book's main point in such a short time truly opens multiple opportunities to grow every area of your life at a faster rate.

    Renee D.

    Great app. Addicting. Perfect for wait times, morning coffee, evening before bed. Extremely well written, thorough, easy to use.

    People also liked

    Start growing with Blinkist now
    26 Million
    Downloads on all platforms
    4.7 Stars
    Average ratings on iOS and Google Play
    91%
    Of Blinkist members create a better reading habit*
    *Based on survey data from Blinkist customers
    Powerful ideas from top nonfiction

    Try Blinkist to get the key ideas from 5,500+ bestselling nonfiction titles and podcasts. Listen or read in just 15 minutes.

    Start your free trial