4 min read

Happy epistemic vigilance day!

Happy epistemic vigilance day!

The University of Amsterdam will be deploying drones to hunt down people who smoke on-campus, its website reported. Using face recognition technology, students and employees who break the rules can be identified and dealt with appropriately:

'Linked to a database of profiles, the drone determines how often targets break the rules. For multiple violations, the drone can switch to a more violent nozzle on its own.' For a first offence, it targets a cigarette lying in the hand, for the second a cigarette lying in the mouth, and for a third offence, it deploys a nozzle with a wider beam so that mouth, hand and intermediate target areas are hit. Academic punitive measures are currently being explored. For repeated offences (four offences or more), credits (ECTS) will then be deducted.
‘Cigarette drones’ should solve UvA smoking problem
The UvA is starting a trial in which intelligent drones will be used to enforce the smoking ban on campus. The drones detect cigarette smoke and, based on actual wind measurements, geo-fencing technology and facial recognition, can determine exactly where and at which target the smoke is coming from…

This is all, of course, ludicrous and a quick glance at the drone's launch date – April 1 – should make it clear to anyone that the story was entirely fabricated. It's April Fools and in many countries, people are deceiving and pranking each other for the fun of it.

But why is it fun to deceive or (perhaps to a lesser extent) to be deceived? Since social learning is pretty much the brand of our species, you would expect us to value signals of trustworthiness. When we learn about the world through the statements of others, even young children are very receptive to signals of reliability (Poulin-Dubois & Brosseau-Liard, 2016). Nurturing those signals gives us the ability to persuade and influence others, so why endanger that by intentional deception? And why laugh about it?

One way to think about this is to consider the deception as play. The psychological motive for play may just be fun, but the biological reason why this motive exists in the first place can be different. We play because we develop ourselves that way and because it positions us in the group. For example, rough-and-tumble play among children might develop their body coordination and emotion regulation, while it simultaneously shows them and others what they are capable of. In addition, play offers a shared experience that can improve social cohesion.

Deception can do something similar. In the classical fool's errand, someone new to a workplace is given an impossible task – usually picking up some non-existing tool, such as as cable stretcher. If the newcomer falls for this prank, this reinforces his position as someone who has a lot to learn, but it is also a shared experience. In many cases, going on the fool's errand also means meeting various people at the workplace. In this sense, you could also consider it a deceptive on-boarding practice.

In retrospect, the duped newcomer is likely to understand that getting the cable stretcher, the bucket of steam or the wireless cord were nonsensical tasks to begin with. They will realize they should have thought a bit better about the tasks and should have checked their plausibility. This might another role for the ritual, which is keeping each other sharp or, more technically, epistemically vigilant.

April Fool's can serve a similar purpose. There may be some form of dominance display in pranks, but it's also a good moment for people to reconsider why they fall for them and to reset their cognitive defences. This is a useful exercise, which does not erode trust as long as the deception is kept within specific boundaries. Perhaps this is why people are supposed to come clean about the pranks they pull and why their deception is limited to roughly one day – I've understood that in some portions of the world, you're not even supposed to prank after noon.

Now using the lens of play obscures a key issue. In play, all participants are aware they are, in fact, in a game of sorts. This is not the case for pranks – the person who is being duped is by definition not 'in on it'. This is why some scholars prefer to consider the April Fools' pranks as rites of passage, which are often associated with pranks and which are centred on unknowing individuals (Dundes, 1988). They note that in Europe, April 1 is the natural transition into a new year and so it makes sense to have rites of passage with each other.

Perhaps this is indeed a better way to look at the ritual, yet it cannot be denied that a day of deception is a cognitive rite of passage, separating the credulous from the critical and perhaps prompting the more gullible to not take testimonials by others for granted. I do not doubt the full picture is more complicated than that. The ritual also feature role reversals (e.g. children fooling adults or the powerless mocking the powerful) and has its own traditions for specific pranks. But at its centre lies the practice in deception. Regardless of how you look at it, April Fools remains a moment at which individuals practice their plausibility checking and persuasion skills in a relatively safe – if not exactly playful – environment. This makes it a functional ritual for a society that wants to maintain a healthy infosphere.


Dundes, A. (1988). April Fool and April Fish: Towards a theory of ritual pranks. Etnofoor, (1), 4-14.

Poulin-Dubois, D., & Brosseau-Liard, P. (2016). The developmental origins of selective social learning. Current directions in psychological science, 25(1), 60-64.