June 20, 2017   |   4min read

Caveman UX: Designing for Humans’ Prehistoric Baggage

Damn. I’ve accidently switched to video mode. Again.

Apple knows that quick access to your iPhone’s camera is critical. We don’t want be fumbling with UI while trying to capture those fleeting moments like a baby’s first smile or, in my case, when the cat has wedged herself into a cereal box.

With iOS 10, a simple right-to-left swipe across the lock screen opens the camera. Nice. But my gripe is not with how I enter the camera. The problem lies in how I exit the camera. To exit and return to the lock screen, I must press the home button. In isolation, neither of these interactions are bad or wrong. But as a pair (enter and exit), they are broken. Why? Because I do not exit the way I came in. And for my human brain, conditioned over millennia in the physical world, this just does not compute.

And here’s the worst part. If I go with my intuition and try to exit by reversing the motion I used to enter (swiping left-to-right), I switch my camera to video mode.


To add insult to injury, when the 2% of my brain that is being allocated to managing this situation recalls that I need to press a big round button at the bottom of the device, I’ll often press the wrong big round button at start taking a video of my sandwich.

Consider the full loop of the interaction

If turning the key to the right locks the door, then turning the key the left will unlock the door. If moving the the handle up turns the faucet on, then moving the handle down will turn the faucet off. In general, the physical world is nicely predictable like this. But, when we enter digital spaces and use digital tools, the laws of physics are no longer at play. Designers can disconnect the on from the off and the in from the out. And because they can, they do. They do it at Apple; they do it at Google; you or your designers might be doing it on a project right now.

We need some design rules for caveman brains

Designers need to remember our caveman roots and all the baggage that comes with being creatures who evolved in the unfortunate constraints of physical space.

But isn’t the very best thing about pixels the freedom from all of those petty rules of physics? In digital space, you can teleport with hyperlinks! A million people can read the same article without killing one tree! You can be in three places at once! You can autocorrect your terrible spelling! You can undo, unsend, and even unfriend! Digital spaces make magic possible. (Queue the sparkles and rainbows.)

But here’s the real talk. If not done right, magic is scary, confusing, and disorienting. Even though our digital world can be 100% liberated from physical constraints, that doesn’t mean they should be. Sure, let’s ditch the annoying things about meatspace, but let’s keep what works. Mainly, let’s respect what our users’ poor lizard brains are always going to assume about any space — physical or digital—and stop dumping them into state-fair “fun” houses like we’re a bunch of evil carnies.

We’ve already covered one anti-evil-carnie rule: an opposite interaction should have an opposite effect. If I lock to the left, I should unlock to the right.

Here’s a second one: when I return to where I came from, I expect to end up in the space I was in previously.

In the physical world, when I walk from my living room into the bathroom, I assume that when I exit the bathroom through the same door I will end up back in my living room. Not the kitchen. Not the backyard. This sounds painfully obvious. But designers of digital environments often drop users into the proverbial backyard. For an example, let’s look at Google Photos.

Below, I am innocently scanning through “All Photos” trying to get organized.


I select a few photos to move into a new album:


Next, I create a new album from my selection.


And then I am taken to that new album, where I can add a name and rearrange photos. When I am ready, I’ll click the check in the upper left corner to tell Google Photos that I’m done playing. So far, so good.


On saving my new Kraków album, a “back” arrow appears in the upper left (my highlight).


Where would you guess that this little arrow might take me? Do you think that maybe, just perhaps, the back arrow should take me BACK? Back to the “room” I was in a moment ago? Back to my stream of “All Photos,” scrolled to the place I left before detouring to my new album? NOPE! Instead, Google takes “back” to All Albums, a screen I have not once visited in this session. I’m in the backyard and I’m not happy.


UPDATE: Good news! As of September 2017, the back button described above is now behaving properly. After creating an album, the left-pointing arrow takes the user back to their photo stream, right where they left off.

I’ll repeat anti-carnie rule two: when I return to where I came from, I expect to end up in the space I was in previously.

There are countless examples of these broken mental models. Turn on by flipping a toggle up; turn off by pressing a button in the upper right corner. Leave your profile to edit your picture; save the changes; end up on your dashboard.

Our brains come with some serious baggage from all those hundreds of thousands working with mainly rocks and dirt. We have some really deep-seeded beliefs about how things should operate. Digital-thing designers need to remember: humans are not just going to drop all their assumptions about objects and space when hopping on a computer. We’ll bring that baggage with us. So design for it.

An article by Sophia Voychehovski, MCE 2017 speaker

portrait sophia

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