There is no clear origin story of the April Fool’s joke. Anthropologist Gunter Hirschflender from the University of Regensburg relays a widely held theory: The French monarch Charles IX moved the time change from April 1st to January 1st in 1564. From then on everyone who continued to celebrate the new year on April 1st became recipients of teasing, mockery and various jokes.

Theory of mind

But when do we start lying? Certain conditions are required for this to happen, explains Philipp Gerlach, professor of general and social psychology at the Fresenius University of Applied Sciences in Hamburg. “It is not enough that I intend to lie. I must know what I know. And also to know what my opponent knows.” This is called “Theory of Mind”: It describes the ability to put yourself in another person’s shoes and see things from their point of view.

Once a year lies are acceptable

Black and white lies

The process of lying is different. The difference lies in the intent: “There are countless lies. In English they are divided into ‘white’ and ‘black’ lies,” says Professor of Anthropology Philip Gerlach and explains: “Black lies are the malicious lies, those with which they are made at the expense of another person. In contrast, white lies are essentially commonly accepted untruths. For example: After a hard day at the office my wife goes to the hairdresser and then comes home. Of course I won’t tell her that I don’t like the hairstyle. So, you tell a little lie to help a person.”

April Fool’s Day or Fake News?

On the internet lies give and take. Psychologist Tilo Hartmann puts April Fools’ Day in a cultural context, which exceptionally justifies conscious lying: “If we don’t lie constantly and every day and agree that one day of the year we can make a joke and laugh at someone’s expense without hurt him then we think we can accept this condition.” The German scientist, however, warns that: “anyone who systematically lies is no longer believed. In other words: You put your reputation and credibility in doubt in order to achieve something in the short term.”

The April Fool’s joke was popular until the beginning of the 21st century. But in the age of social media, these jokes seem somewhat dated. Anthropologist Gunter Hirschflender predicts that “April Fools’ jokes will either change over the years, or they will die out. What is certain, however, is that, like everything else in culture, it cannot remain as it is.”