The Diderot Effect is used to describe the fact that when we buy something new, we’ll sometimes end up replacing our old possessions with things that match the new item.
For instance, if you buy a cool new shirt, you may feel the need to buy some cool new trousers to match. And perhaps a new pair of shoes, a jacket and before you realise it, you have a whole new wardrobe.
New clothes, new you. And maybe an empty bank account.
The Diderot Effect is often mentioned alongside reasons people overspend and it’s not hard to see why: a single item can trigger a string of purchases that could make the ‘new you’ someone who has to take up a few night time Deliveroo shifts in addition to their regular job.
The Diderot Effect tells us two things about ourselves:
1. We buy goods that complement each other and build towards a unified image we have of our own identity.
2. If we obtain an item that doesn’t fit in that identity, we’ll be tempted to either disregard it or we’ll make it the centrepiece of our new identity (the ‘new you’).
This means we care about buying things that make sense together (at least to ourselves) and that we believe fit with who we are.
However, sometimes a strange item that we just really, really like might float in and because it feels so out of place, we’ll start replacing the other things we own so the new item won’t be out of place anymore.
Denis Diderot, an 18th century French philosopher who this Effect was named after, ran into that issue when he was gifted a fancy new bathrobe.
All of his other possessions simply didn’t live up to the pristine nature of the new robe. He ended up replacing his shabby possessions to suit his new bathrobe.
In a regular day-to-day, the Diderot Effect could mean that, just like Monsieur Denis Diderot, you’ll go out and buy whatever you feel matches that classy new bathrobe.
For most people this may not pose a serious problem. Sure, they’ll feel a dent in their wallet that month, but they’ll recover.
Many, however, could use up any savings they had and even go into debt to satisfy their need for the new. Here are two pitfalls to look out for:
1. Seeing options is enough to trigger the Diderot Effect – window-shopping is not always as innocent as it seems. You don’t need to own something new to feel the urge to switch your possessions, even just seeing options of different ‘new you’s’ can do it.
2. Beware the snowball effect – it might start with new clothes, but suddenly, the wardrobe doesn’t seem right for the new clothes and then the bedroom furniture doesn’t seem right with the new wardrobe and then the rest of the house doesn’t seem right with the new bedroom, and on it can go. Your key defence against these traps is awareness. If you are aware that your purchases are being driven by the Diderot Effect, you might be able to stop it.
A wider view
The term Diderot Effect was coined in 1988 by Grant McCracken, who explained that people’s purchases don’t depend solely on an item’s functionality or practicality.
The traditional belief that people made purely rational decisions would assume they would only replace or upgrade something once it no longer worked.
However, McCracken said that people’s purchases are tied more closely to their identity than to pure practicality.
This is an idea that companies have been playing with for a long time to convince people to buy not just one product, but a whole series of products.
We can see it very clearly with smart home devices. You could just buy an Apple speaker, but you won’t be able to access all its features unless you also have an Apple TV, an iPhone, iWatch and maybe even more peripherals.
A great example is also mentioned in this video on the Diderot Effect by the BBC: IKEA. Anyone who has been to an IKEA is familiar with their display rooms.
These fully designed rooms are meant to give you a sense of the type of person who would live there and if you think that person is you, then buying that new sofa might also mean buying the TV furniture and the coffee table, and so on.
You’re no longer being sold on a single product, but on an entire new lifestyle, a ‘new you'.