March 24, 2022
Michael Merzenich, PhD

Mark Twain noted that “[t]he first of April is the day we remember what we are the other 364 days of the year.” It’s also one of my favorite days of the year.

I’ll admit that I revel in hearing about — or even falling for — a good harmless prank. And, as a grandfather, I confess that I especially enjoy pulling a grandchild’s string, in a genial, grandfatherly way — and perhaps not just on April Fools’ Day.

Surprises keep you on your toes and engage the brain in ways that generate new neural connections and learning. Surprises also stimulate the brain chemistry that keeps your brain cells and systems healthy — regardless of whether the surprise is one that brings you joy or one that creates challenges for you.

Naturally, I hope any surprises in your life — and on the special day of April Fools’ — will be delightful ones!

Your Amazingly Fast Brain

Our brains are masters at making quick decisions on the basis of what can be very sparse information. In our native human state, any surprise turns our brain onto “alert;” rapidly responding in the face of the unexpected can obviously be critical for our survival.

Sometimes, however, the brain is a little too quick and a little too decisive — and that’s when the trap can be sprung and you can be outwitted, tricked, bamboozled!

If it’s done in good spirits, the discovery of being led down that garden path can be almost as much fun for the “victim” as for the “perpetrator.”

The Chemistry of Being Fooled

Your brain releases several neuromodulators (chemicals that change your brain) whenever something unexpected or novel occurs in your world.

For example, noradrenaline “turns up the lights” to sharpen your attention and to amplify the brain’s response to the unexpected event.

The release of another chemical, acetylcholine, increases the strength and fidelity that support your long remembering the details and the meaning of that unexpected experience.

If the surprise is positive or delightful — as it is when you discover that you’ve been the successful perpetrator or the recipient of a clever and warm-spirited prank — your brain also releases dopamine and serotonin, which still further embeds the memory of the surprise; engenders your happy and elevated good spirits; and triggers associated physical responses in facial expression, body movements, and laughter.

The enjoyment and memories that we associate with these hijinks, and the great good spirits for all concerned, helps explain why this peculiar little holiday — neither religious nor historic — has been celebrated for a very long time worldwide (it dates back to at least the sixth century BC in Persia). In France, there’s a tradition of taping a paper fish onto someone’s back on “poisson d’avril” — literally, “April Fish.” In Scotland, they love a prank so much they extend the holiday to include April 2nd. In Germany and England, they’re more efficient; all pranks must be completed by noon. No matter what the specific local traditions, April Fools’ is all about that special form of tomfoolery that can result in “You got me!” laughter.

Why You Fall for It

So why is it so darn easy to fool our brains?

We humans have lots of tricks to convince others that something false is true. You may not be convinced by me saying something is so, but if I can compound enough evidence to build credibility, I often succeed in my deception.

For example, maybe I get Mom to come in on the trick. Now, you’re caught off-guard because Mom is a well-known truth-teller. Perhaps I back up my story with half-truths or adopt a tone of voice (or a turn of phrase) that captures your imagination in a way that leads to your swallowing my blather. Researchers have conducted studies in which they’ve deployed these and other strategies to teach unsuspecting experimental subjects to believe all kinds of completely ridiculous things.

Marketers can be masters of using such strategies to promote regrettable decisions. Politicians can be especially adept at the art of deception, which is perhaps what led Will Rogers to observe that “the problem with practical jokes is they often get elected.”

Magicians may be the best example of people whom we respect for their ability to deceive. They are lauded and paid for misleading us and have quite a bag of tricks. Your brain is sampling information moment by moment, and in the intervals between those moments — as a magician deflects your attention, so you don’t see it — they can trick you into believing that the elephant vanished into thin air.

A Mistake Induced by Others

It’s actually pretty easy to fool — or be fooled by — another person.

Of course, we all make mistakes — all the time. Sometimes, we can even believe strongly in things that are false. People may witness a crime and be sure about what they saw, but studies show that eyewitness testimony is not terribly reliable.

I once wrote an autobiography (self-published) to share the stories of my childhood with my grandchildren and was more than a little surprised to discover that my five siblings had substantially different recollections of the details of events that I vividly remembered. I shouldn’t have been surprised, because I knew that scientists have documented the unreliability of long-term memory many times over. We’re all capable of fooling ourselves, of unwittingly changing our stories as the years go by, and of holding onto strong beliefs that are (to be polite) inaccurate.

Of course, when it came to those different recollections of childhood put forth by my brothers and sisters, I had to tell all of them to go write their own damn book.

A Foolproof Future Awaits

Owing to advances in brain science — notably the discovery of neuroplasticity — our brains can be exercised to sharpen and strengthen its chemical and physical machinery and increase its performance abilities throughout life. This has led to the development of computerized brain exercises, which have been shown to greatly reduce our brains’ immediate and long-term error rates.

As a result, we’re now on the cusp of an extraordinary epoch in which we understand how to sharpen our human abilities to distinguish fact from fiction. As people make increasing use of this new form of brain training, one can envision a future era in which most citizens will hardly ever make foolish errors and, just a little sadly, will be much less likely to fall for someone’s prank on the first of April.

And if you were beginning to believe that for just a moment…

…April fool!