The Diderot Effect: Why We Buy Things We Don’t Need
5 min read

The Diderot Effect: Why We Buy Things We Don’t Need

The Diderot Effect: Why We Buy Things We Don’t Need

Denis Diderot was a famous French philosopher who lived nearly his entire life in poverty. His fortune would change in 1765.

At the time, Diderot was 52 years old and his daughter was about to be married. He wanted to help pay for the wedding but couldn’t afford to do much due to his lack of wealth. Despite this, Diderot was well-known in Europe because he was a major writer of Encyclopédie, a defacto encyclopedia of the time.

When the Empress of Russia, Catherine the Great, heard of Diderot’s financial troubles she offered to buy his library from him for £1000 GBP, which is about £35,609.58 in 2020. This gave Diderot the money he needed to pay for his daughter’s wedding. In fact, Diderot even set aside some money and bought himself a new scarlet robe.

That’s when everything went wrong for him.

The Diderot Effect

Diderot’s new robe was beautiful. He was never able to afford such a robe himself before, so this was quite the stroke of good fortune. He found the robe so beautiful, that he immediately noticed how out of place it looked when put next to the rest of his clothes and “commoner” possessions. Almost on a whim, he felt the urge to upgrade his home in order to match his new fancy robe.

“No more coordination, no more unity, no more beauty!”
— Denis Diderot

He bought a fancy new rug from Damascus to replace his old, bland one, upgraded his kitchen table, and decorated his home with extravagant sculptures and statues. His uncomfortable straw chair was replaced by a new top-of-the-line leather chair.

What happened here?

Before receiving the large payment from the Russian Empress, Diderot would have never bought such a fancy rug, or extravagant sculptures, or upgraded to a leather chair. Diderot’s purchases were completely reactive, a direct result of emotions caused by his new wealth.

Such reactive purchases have become known as the Diderot Effect. It sits on two core ideas.

The first is that we form an identity from our possessions. If we buy many books then we see ourselves as a reader, many suits or dresses and we see ourselves as high-class.

The second is that if we buy something new, and that new item does not align with our current identity, then we will be more inclined to purchase more new things that align with our new identity. This creates a spiral of consumption which leads us to buy more and more things, to make sure everything is matching and up to the same level.

Why We Buy Things We Don’t Need

Many of us have fallen victim to the Diderot effect — I know I certainly have. Every time I buy a new shirt I feel like I need a new pair of pants to go with it. If I have a new shirt and pants, well might as well throw in the tie. And if I have all of those, I mean I definitely need to upgrade my shoes.

This spiral of consumption can happen with just about everything. With a new phone, you might get new headphones or a new charger even if you have ones that work perfectly fine already. A new car and you feel like you need a car charger for your cell phone, a tire pressure gauge, and an emergency flashlight. Get a new pan for cooking and now for some reason, you feel like you need a new spatula — oh and might as well grab a new salt shaker while we’re at it.

Did you really need all of those other things? Getting a gym membership doesn’t necessarily mean you need a personal trainer and a foam roller and knee sleeves. A new shirt doesn’t mean you need matching shoes. But hey, they go together right? RIGHT?….

We have a natural tendency to make sure our lives are full. We are never looking to downgrade or reduce what we have, quite the opposite in fact. As soon as we get something new, we have our eyes set on the next thing. And if we upgrade one part of our lives, we’re very much inclined to upgrade all of the other parts, just to maintain consistency.

“The purchase of a new home is the impetus for replacing old furniture; a new jacket makes little sense without the right skirt to match; an upgrade in china can’t really be enjoyed without a corresponding upgrade in glassware. This need for unity and conformity in our lifestyle choices is part of what keeps the consumer escalator moving ever upward. And ‘escalator’ is the operative metaphor: when the acquisition of each item on a wish list adds another item, and more, to our ‘must-have’ list, the pressure to upgrade our stock of stuff is relentlessly unidirectional, always ascending.”
— Juliet Schor

How to Overcome Spiralling Consumption

We’ve learned about the Diderot Effect and how things can spiral out of control. Now it’s time to grab the steering wheel again and get ourselves back on track. While constant upgrading and ascending consumption are our natural inclinations, we don’t have to follow those paths. We can take a more conscious and healthier approach.

Reduce exposure

Most of the actions we take are triggered by some subconscious habit. For example, we’re quick to buy things on sale, somehow feeling that because it’s on sale we HAVE to buy it now. The trick is of course that we might have never bought that thing if it wasn’t on sale — it’s the psychological trigger that the item is on sale that go us interested.

One of the quickest ways to reduce the power of the Diderot Effect is to reduce the occurrence of those triggers in our daily lives. Unsubscribe from commercial emails that send you the latest deals — you can check out the website when you actually need something. Or even better, block out certain websites from your computer by using browser extensions like WasteNoTime. In general, try to reduce the amount of exposure you have to advertising and people trying to sell you things.

Automate to optimize

It’s hard to limit your spending at the mall or online shopping if every time you get a paycheck your money is sitting right there, just waiting to be spent.

Instead, you can automate a portion of your paychecks to go straight to a savings or investment accounts. Plenty of banks offer this kind of service. With the spending money out of sight (and put in a better place), it’ll be a lot easier to control your spending.

Ask yourself

One trick I like to use is to go through a quick personal survey every time I’m about to buy something:

  • Do I have anything else like this or that serves the same purpose?
  • If I buy this, what else can I not buy after I’ve spent the money? (since now I have less money to spend on other things)
  • Do I actually need this? Or do I just want it? How much will it actually benefit me?
  • If I do need this item, can I get it at a cheaper price or borrow it from someone?

It’s a short survey, but it helps tremendously in avoiding buying things I don’t need. Usually, the answer to at least one of those questions stops me from buying.

Break from buying

Take a break for one month from buying anything new. No new clothes, tech stuff, equipment, or anything you’d classify as things. Try to live without any of those new things for a month. Then try two months. Pretty soon, you’ll see that you didn’t need those new things after all. All it took was time.

Our natural tendency is to consume more, to fill up space, and make sure everything fits. But this spiralling consumption can often leave us dissatisfied, as we’re always looking for the next best thing.

But life really doesn’t have to be that way. We don’t have to constantly consume. Instead, we can optimize our life, filling it only with what makes us truly more productive, fulfilled, and happy.

“The secret of happiness, you see, is not found in seeking more, but in developing the capacity to enjoy less.”
— Socrates

For more reading related to the Diderot Effect and how to form good habits, here are a couple of books:

The Overspent American by Juliet Schor

Atomic Habits by James Clear