"Your app makes me fat" - by Kathy Sierra is one of my favorite articles. Sometime mid-2023 her site, Serious Pony, went down and the article is no longer available.

I was able to retrieve it on the Wayback Machine, but since I reference it often I wanted to also preserve it here. All the brilliant credit goes to Kathy - you can support her by checking out her book: Badass: Making Users Awesome

Your app makes me fat

By Kathy Sierra

Originally published: July 24, 2013

In 1999, Professor Baba Shiv (currently at Stanford) and his co-author Alex Fedorikhin did a simple experiment on 165 grad students.They asked half to memorize a seven-digit number and the other half to memorize a two-digit number. After completing the memorization task, participants were told the experiment was over, and then offered a snack choice of either chocolate cake or a fruit bowl.

The participants who memorized the seven-digit number were nearly 50% more likely than the other group to choose cake over fruit.

Researchers were astonished by a pile of experiments that led to one bizarre conclusion:

Willpower and cognitive processing draw from the same pool of resources.

Spend hours at work on a tricky design problem? You’re more likely to stop at Burger King on the drive home. Hold back from saying what you really think during one of those long-ass, painful meetings? You’ll struggle with the code you write later that day.

Since both willpower/self-control and cognitive tasks drain the same tank, deplete it over here, pay the price over there. One pool. One pool of scarce, precious, easily-depleted resources. If you spend the day exercising self-control (angry customers, clueless co-workers), by the time you get home your cog resource tank is flashing E.

The tank is empty.

And even if you loved solving tough puzzles at work, the drain on your self-control still happens. One pool. Whether the drain was from something you love or hate doesn’t matter.

Cognitive resource tank don’t care.

You snap at the kids or dog over the tiniest thing.

Or the dog snaps at you.

An experiment asked one group of dogs to sit, just sit, nothing else, for a few minutes before being released to play with their favorite treat “puzzle” toy (the ones where the dog has to work at getting the treats out of it). The other group of dogs were allowed to just hang out in their crates before getting the treat puzzle.

You know where this goes: the dogs that had to sit — exercising self-control — gave up on the puzzle much earlier than the dogs that were just hanging out in their crate.The dogs that were NOT burning cognitive resources being obedient had more determination and mental/emotional energy for solving the puzzle. Think about that next time you ask Sparky to be patient. His cognitive resources are easily-depleted too.

Now think about what we're doing to our users.

If your UX asks the user to make choices, for example, even if those choices are both clear and useful, the act of deciding is a cognitive drain. And not just while they're deciding... even after we choose, an unconscious cognitive background thread is slowly consuming/leaking resources, "Was that the right choice?"

If your app is confusing and your tech support / FAQ isn't helpful, you’re drawing down my scarce, precious, cognitive resources. If your app behaves counter-intuitively – even just once – I'll leak cog resources every time I use it, forever, wondering, "wait, did that do what I expected?". Or let's say your app is super easy to use, but designed and tuned for persuasive brain hacks ("nudges", gamification, behavioral tricks, etc.) to keep me "engaged" for your benefit, not mine (lookin' at you, Zynga)... you've still drained my cognitive resources.

And when I back away from the screen and walk to the kitchen...

Your app makes me fat.

If our work drains a user’s cognitive resources, what does he lose? What else could he have done with those scarce, precious, easily-depleted resources? Maybe he’s trying to stick with that diet. Or practice guitar. Or play with his kids.

That one new feature you added? That sparkly, Techcrunchable, awesome feature? What did it cost your user? If the result of your work consumes someone’s cognitive resources, they can’t use those resources for other things that truly, deeply matter. This is NOT about consuming their time and attention while they're using your app. This is about draining their ability for logical thinking, problem-solving, and willpower after the clicking/swiping/gesturing is done.

Of course it's not implicitly bad if our work burns a user's cog resources.Your app might be the one place your user wants to spend those resources. But knowing that interacting with our product comes at a precious cost, maybe we’ll make different choices.

Maybe we’ll think more about what our users really care about. Maybe we’ll ask ourselves at each design meeting, “is this a Fruit-choosing feature or a Cake-choosing feature?” and we’ll try to limit Cake-choosing features—the ones that really drain them — to that which supports the thing they're using our app for in the first place.

(Yes, cognitive resources can be partly replenished throughout the day by getting glucose to the brain, but be careful with that. A high-protein snack combined with small infrequent sips on a sports drink can help, a lot.)

But even if we can justify consuming our user's cognitive resources while they're using our product, what about our marketing? Can we honestly believe that our "content marketing" is a good use of their resources? "Yes, because it adds value." we tell ourselves. But what does that even mean? Can we honestly say that "engaging with our brand" is a healthy, ethical use of their scarce, precious, limited cognitive resources? "Yes, because our content is useful."

And that's all awesome and fabulous and social and 3.0ish except for one, small, inconvenient fact: zero sum. What you consume here, you take from there. Not just their attention, not just their time, but their ability to be the person they are when they are at their best. When they have ample cognitive resources. When they can think, solve-problems, and exercise self-control. When they can create, make connections, and stay focused.

Is that "content" worth it? Maybe. But instead of "Is this useful?" perhaps we should raise the bar and ask "Will they use it?" (and so, yeah, I'm more than a little self-conscious about typing that as I consume your cognitive resources. But I didn't start Serious Pony to save your cognitive resources; I want to help save the cognitive resources of your users).

I'm not against "content marketing". On the contrary, it's nearly the only form of cog-resource-draining marketing that can be "worth it". It's the one form of marketing that can help people become better at something they care about. It's one form of marketing with the potential to deliver the user-learning so few companies care about. Content marketing can (and should) be "the missing manual." It can (and should be) the inspiration for our users to learn, get better (at the thing they care about), and connect with other users.

But if it's "content" designed solely to suck people in ("7 ways to be OMG awesome!!") for the chance to "convert", we're hurting people. If we're pumping out "content" because frequency, we're hurting people. I'm hurting some of you now. That's on me. It's why I try to use graphics to make the key point, so you don't have to read the post (also because I'm really rambly-aroundy, I know, workin' on it.)

My father died unexpectedly last week, and as happens when one close to us dies, I had the "on their deathbed, nobody thinks..." moment. Over the past 20 years of my work, I've created interactive marketing games, gamified sites (before it was called that), and dozens of other projects carefully, artfully, scientifically designed to slurp (gulp) cognitive resources for... very little that was "worth it". Did people willingly choose to engage with them? Of course. And by "of course" I mean, not really, no. Not according to psychology, neuroscience, and behavioral economics research of the past 50 years. They were nudged/seduced/tricked. And I was pretty good at it. I am so very, very sorry.

My goal for Serious Pony is to help all of us take better care of our users. Not just while they are interacting with our app, site, product, but after. Not just because they are our users, but because they are people.

Because on their deathbed, our users won't be thinking,"If only I'd spent more time engaging with brands."

Help them conserve and manage their scarce, precious, easily-depleted cognitive resources for what really matters. To them. And don't forget to take care of your own. Think of the kids. Think of Sparky.