Calling bullshit: The Art of Skepticism in a Data-Driven World (book)

In his 1996 book The Demon Haunted World, Carl Sagan wrote the chapter The Fine Art of Baloney Detection. A recently published book by Carl Bergstrom and Jevin West, Calling Bullshit. The Art of Skepticism in a Data-Driven World, can be seen as an extension and update of that chapter. The book is about bullshit, or nonsense claims.

Bullshit is as old as humanity and even older. Many other animal species also employ all kinds of deception. Some animals sound the alarm to suggest that a predator is coming to lure other animals away from food in order to get to it themselves. But besides humans, there are only a few animal species that deliberately mislead. This is because deliberately misleading others requires a fairly complex brain.

Bullshit elevated to a form of art

Conscious deception requires a brain capable of developing a theory of mind. That is, a brain that is able to imagine the effects of its own behavior on other animals. In addition to some monkeys and raven-like species, only humans are capable of this. And how. Reading this book, it is hard to believe the degree to which some people have turned bullshit production into a true art.

Easier to deceive than to fight deception

One of the problems with bullshit is that it is much easier to produce than to fight. A second problem is that bullshit is often sensational and therefore easier to spread than correct information. An example of this is the bullshit story that vaccines are said to cause autism. While these claims, introduced by faulty research by Andrew Wakefield, have often been debunked, many continue to believe in them and this fact has cost countless human lives.

Media and technology

Modern media and technology worsen the harmful effects of bullshit. Traditional media are increasingly driven by sales figures, which, in practice, means that they are well rewarded for posting or broadcasting sensational bullshit. The problem may be even greater with social media such as Facebook, YouTube and Twitter. Algorithms determine what you see.

How algorithms spread bullshit

Two problems with these algorithms are that they create echo chambers and they promote bullshit. As for the first, they show you more and more of what they think you want to see. As for the second, if you search for something on YouTube about, say, the moon landing, you will soon be bombarded with all kinds of videos claiming that it never happened. YouTube's algorithm is indifferent to what is true. Its sole purpose is to hold your attention for as long as possible with whatever content.

New forms of bullshit

The book examines all kinds of relatively new forms of bullshit. For example, have you heard of a 2016 study claiming that they had developed a computer system that allowed them to predict whether someone was a criminal purely based on photos of faces? In the book you can read why this is nonsense.

Correlation vs. causality

The authors pay a lot of attention to correlation versus causality. That things are interrelated does not mean that one predicts the other. But we are constantly confronted with information pretending that correlation does imply causation.

Based on what data?

Bullshit can often also be exposed by looking at the data on the basis of which conclusions are drawn. An important phenomenon to know is that of selection bias, also known as restriction of range. The authors illustrate the importance of this phenomenon in the so-called Berkson's paradox. This paradox explains an observation which many people (apparently) have made while dating: that cute guys are often unkind. Actually, kindness and cuteness are hardly or not at all correlated. But through two choices that we make ourselves while searching for dates, we create a (negative) correlation between the two characteristics. Read the book for the explanation.


The book explores many ways in which people can deceive through graphs, tables and other visualizations, as well as how science is by no means free from bullshit.

The fight against bullshit

The authors say it is extremely important to keep fighting bullshit. Democracy is of great value and it cannot exist without well-informed citizens. As citizens are bombarded with unreliable information which they cannot properly evaluate, democracy is endangered.

Government regulation and technology can play important roles in fighting bullshit, but education is most important. We need to teach children the skills to analyze critically and to reason logically early on in their lives. There is still a world to gain here.