Try This At Home: The Hollow Face Effect

Education Featured GeekMom
Make this little pet dragon who follows your every move. Image by Lisa Kay Tate
Make this little pet dragon who follows your every move.
Image by Lisa Kay Tate

We like to call it the Haunted Mansion Effect in our house.

This is the eerily fun illusion of having the seemingly inanimate facial features on a statue or bust follow your movements across the room; up and down, side-to-side, or pretty much everywhere.

One common term for this is the Hollow Face Effect, and even though its most famous usage can be seen by millions of Disney Park visitors each year from the hallway busts in the Haunted Mansion, this effect has been used for several years in cathedrals, galleries, and science centers.

One reason it is so fascinating is it is an extremely easy concept, and it’s all about perspective.

Here’s how it works. The moving face in the hollow face effect is merely a concave sculpture, like a mold or bowl. When looked at in the right lighting, and at the right angles, it appears to be a normal, convex bust or statue. Your brain wants to see a regular statue, so it tricks your mind into thinking it is.

dragon shots
How a concave “hollow face” is (left) and how it appears (right) is all a matter of perspective. Images by Lisa Kay Tate

This is coupled with another slightly more difficult concept, called pareidolia, which is, in simple terms, the mind’s ability to see faces in patterns.  A face, of course, is normally convex. For example, the tip of the nose is closer to the viewer than it’s ears and cheekbones.

When you look at a hollow face sculpture, the outer edges of the mold become hidden as you move your own head, causing your mind and eye to think the head is turning towards you, rather than being slightly covered up. A simple diagram and more detailed explanation of how the effect works can be found on

sagrada familia
Even architect Antoni Gaudí used the hollow face effect in one of the many sculptures in Spain’s famous Sagrada Familia.
Public Domain image.

Now, here’s the best part; you can make your own moving sculpture in a matter of minutes. Thanks to a recent viral video of a T-Rex illusion that has gathered more than 3.5 million views, people have rediscovered something called the “Gathering for Gardner” dragon, created for an event celebrating the late scientist and mathematician Martin Gardner. The pattern for this dragon can be found on several educational and science sites, such as Grand Illusion.

It works fantastically, too. We made a video of our own dragon mugging for the camera.

It’s easy, all ages can participate, and it can be a quick after-school or lunchtime project.  Plus, who doesn’t want their own very, very attentive pet dragon.

Liked it? Take a second to support GeekMom and GeekDad on Patreon!
Become a patron at Patreon!

10 thoughts on “Try This At Home: The Hollow Face Effect

  1. I remember this illusion extremely well, from when I wrote a report on Disney’s Haunted Mansion attraction (I’m also a former cast member from WDW). Another added bonus with this particular illusion is that, even when you know how it works, you still can’t correct your brain into seeing it otherwise: you might KNOW that the face is convex, but your brain refuses to BELIEVE that it is.

    1. Click on my post where it says Grand Illusion. That should take you right to it. If not, try Googling “Gatherning for Gardner dragon” and you’ll find several cute designs. I know there are green and red dragons out there, too for a little variety. I would just print it out on regular card stock.

  2. Hi Lisa,

    LOVE that you picked up the Dragon Illusion to share with your readers – this illusion has been near and dear to our hearts since we distributed it at the Gathering for Gardner years ago! I wanted to point you to a fantastic free download we offer on our site that your community is welcome to download, print, fold, and stare at endlessly – enjoy 🙂

    We’ve got more illusions and loads of mind challenging games and puzzles that GeekMoms and Dads can’t get enough of, happy to share the fun if you’re interested in seeing the latest and greatest from ThinkFun – just shoot me an email at cfixler at thinkfun dot com!


Comments are closed.