We can instantly judge whether a face is male, female, happy, angry, older or younger.
But strangely, when a face is turned upside down (inverted), we seem to lose the ability to judge even the simplest things such as facial expressions.
If you don’t believe that inverted faces are harder to judge, we’re going to test you.
Here’s a quick pre-test to give you the general idea before you try the real test!
Does this face look ‘normal’ or ‘abnormal’?
If you cover up the photo on the right, the upside down one almost looks normal even though we’ve inverted the eyes, eyebrows, and mouth. When you look at the two of them side-by-side though, it’s obvious something isn’t right.
If you thought that was fairly easy, click the button and see how you do with the next three inverted faces.
At the end, we’ll see how well you and other people could pick the normal and abnormal faces.
Why was it so hard to judge whether a smiling mouth had been turned into a pout when the face was inverted?
Scientists are unsure why these strange faces look so normal when they’re upside down (or inverted).
When faces are the right way up, we ‘understand’ faces as a whole based on their internal components. This is called judging the face holistically.
But when you look at an inverted face, you seem to lose the ability to process it holistically. Instead, you analyse individual features (eyes, nose and a mouth), which makes it harder to detect that something is wrong with the inverted face.
This is often called The Thatcher Illusion or Effect, because a photo of former British Prime Minister Margaret Thatcher was manipulated by Peter Thompson of the University of York in England.
This effect may not cause a problem in every day life because really, how often do you need to judge upside down faces?!
The area of your brain that’s active when you analyse upright faces is the fusiform facial area, which borders your brain’s temporal and occipital lobes.