TikTok users are seriously creeped out after discovering the ‘Thatcher Effect’

A psychologist is going viral on TikTok after explaining an illusion that has users seriously creeped out.

Dr. Julie Smith is a clinical psychologist based in Hampshire, England. In addition to her day-to-day work, she also has a popular TikTok page where she shares little-known facts about her field.

In a recent clip, Smith explained the Thatcher Effect, a phenomenon that explains some pretty crazy details about how our brains work.

The video features upside-down photos of celebrities — such as Kanye West and Adele — which appear completely normal when they’re inverted. However, if you flip your screen and view them right side up, they look … very scary.


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♬ Dr Julie Smith The Thatcher Effect – Dr Julie Smith – Psychologist

Confused? Freaked out? That’s the Thatcher Effect.

Here’s what’s going on: The eyes and mouths of the subjects in the photos have been flipped upside down. Because our brains aren’t as used to recognizing facial features when they’re inverted, we perceive the upside-down photos as being totally normal.

But, when the photos are changed back to normal, our brains can notice what’s wrong. Here’s another example, featuring Justin Bieber — because why not (courtesy of http://thatchereffect.com)?

Credit: Getty Images/http://thatchereffect.com

The phenomenon has been around since the ’80s and is named after Margaret Thatcher, the former British prime minister whose photo was used in the original experiment.

Still, plenty of TikTok users seemed unaware of the illusion until Smith’s video. Many called the celebrity photos “horrifying” and “scary.”

“I was not prepared for that,” one user wrote.


“What in the world?” another asked.

The In The Know staff, most of whom had also not heard of the Thatcher Effect, had a similar response. Plenty of our co-workers were freaked out by the illusion, so, of course, we had to try it ourselves.

To start, I used Photoshop to (poorly) flip my own eyes and mouth, then flipped that entire image upside down. You don’t have to tell me: I know I look like a monster.

Credit: ITK

A few of my brave co-workers also agreed to have their faces flipped, which was probably a poor decision. First up, my co-worker Mark. Sadly, his mustache didn’t fully survive the transformation.

Below, you’ll see three versions of Mark’s face — the original, his “Thatchered” face flipped over and then his “Thatchered” face right side up.

Credit: ITK

Even with the mustache error, Mark’s second photo seemingly looks more like the first image than the third one. That’s despite the fact that the second and third photos are totally identical.

To demonstrate this point further, I tried the effect on my co-worker Alex. This time, I flipped just her eyes and left her mouth normal (you’re welcome, Alex).

Credit: ITK

So, which image really looks different? Obviously, these Photoshop jobs are beyond amateur, but they do show just how creepy the effect can be.

If you liked this story, check out In The Know’s article on why millennials are scared of teenage girls.

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