Health Team

How to be a human lie detector of fake news, according to the latest science

Fake news existed long before the internet.

Posted Updated

David Robson
CNN — Fake news existed long before the internet.

In an essay on political lying in the early 18th century, the writer Jonathan Swift noted that "Falsehood flies and the truth comes limping after it." You have to hire a train to pull the truth, explained English pastor Charles Spurgeon in the 19th century, while a lie is "light as a feather ... a breath will carry it."

Clearly, humans have always been susceptible to mistruths. And social networks simply provide another way to propel falsehoods.

MIT researchers recently studied more than 10 years' worth of data on the most shared stories on Facebook. Their study covered conspiracy theories about the Boston bombings, misleading reports on natural disasters, unfounded business rumors and incorrect scientific claims. There is an inundation of false medical advice online, for example, that encourages people to avoid life-saving treatments such as vaccines and promotes unproven therapies. (Gwyneth Paltrow's Goop is just one example.)

The researchers concluded that "falsehood diffused significantly farther, faster, deeper, and more broadly than the truth in all categories of information."

And it's not necessarily the young that are more gullible either. A separate study found that those over age 65 shared nearly seven times as many fake news articles as 18- to 29-year-olds. Older is not always wiser.

The psychological research does, however, offer us a silver lining to this storm cloud, with various experiments demonstrating that people can learn to be better lie detectors with a little training in critical thinking.

Inoculating yourself from lies

These efforts are often called "inoculations," since they use a real-life example in one domain to teach people about the strategies used to spread lies and therefore equipping people to spot them more easily. Educating people about the tobacco industry's attempts to question the medical consensus on smoking, for example, led people to be more skeptical of articles denying climate change, according to one study.

Another project aimed to inoculate students at North Carolina State University in Raleigh, involved a course on misinformation throughout history. The class was taught about everything from the myth that aliens somehow built the Egyptian pyramids to the theories that NASA's moon landings were faked. Along the way, the students had to identify the erroneous logic that helped create the arguments, and the motivations that may lead some people to spread those ideas.

Following the course, the students were less likely to believe in a range of false beliefs that were not even covered in the course, such as the idea that 9/11 was an inside job. The inoculation appeared to be equipping them with a general skepticism that seems to escape traditional education.

If you would like to improve your own lie detection, a good first step is to learn the common logical fallacies -- red herrings, appeals to ignorance, straw men and "ad populum" appeals to the bandwagon -- that purveyors of misinformation may use to create the illusion of truth.

The Book of Bad Arguments is a free online resource that provides a good introduction to those terms, according to Alicia McGill, who taught the "inoculation" course on misinformation throughout history at North Carolina State University.

Questions to ask yourself when confronted with possible fake news

When examining a new claim, you would do well to ask yourself the following questions:

• Who is making the claim? What are their credentials? And what might be their motives to make me think this?

• What are the premises of the claim? And how might they be flawed?

• What are my own initial assumptions? And how might they be flawed?

• What are the alternative explanations for their claim?

• What is the evidence of their claim and how well do they fit with the opposing explanations?

• What further information do you need before you can make a judgment?

You could also try basic strategies such as cross-checking different outlets and finding the original source of a claim. You might also look at independent fact-checking websites used in the MIT study such as Snopes, PolitiFact and

And pay particular attention to the way the information is presented. We tend to show more faith in a claim if it is accompanied by a photo, for instance -- even if it adds no additional evidence to the particular claim at hand. (A headline about a celebrity death is more believable, for example, if it appears next to a generic stock image of the person.)

It is also important to be aware of our own partisan biases. We are more likely to believe something if it confirms our existing world view, while we will happily dismiss anything that disagrees with our pre-existing beliefs.

The psychological literature offers us one good strategy against bias, called the "consider the opposite" method. This involves asking yourself whether you would have been so credulous of a claim if its opinions had differed from your own. And if not, what kind of additional scrutiny might you have applied? This should help you to identify the weaknesses in your own thinking.

Honing these skills will not just reduce embarrassment when discussing the news with your friends or co-workers. Studies have found that someone's critical thinking skills can protect them from flawed decisions in all areas of life, from being misled by a fad diet, to falling for scams, getting in debt and even landing in jail.

By appraising evidence more rationally, you will avoid being duped by others -- and yourself.

Falsehoods may fly, but with this lie detection kit, you can better ensure your actions and beliefs remain grounded in the truth.

Copyright 2023 by Cable News Network, Inc., a Time Warner Company. All rights reserved.