The Diderot Effect is what happens when the upgrade of one personal possession causes a cascade of additional desired upgrades. It was named after a French philosopher (and co-founder of Encyclopédie) "Denis Diderot", who was broke, came across some money, got a nice fancy silk robe, then replaced basically everything else he owned to match the "quality" of his robe, and was broke again.

The Diderot Effect is an example of Lifestyle Creep and leads to no real overall increase in happiness or satisfaction due to the Hedonic Treadmill.

Examples

• You buy a new phone - which needs a new case & charging stand, and suddenly your computer seems a bit out of date, and your watch starts to feel old
• You get a new couch - which makes your living room feel weird, so you get a new rug & end tables, then new chairs

Obtaining a new possession often creates a spiral of consumption which leads you to acquire more new things. As a result, we end up buying things that our previous selves never needed to feel happy or fulfilled. - James Clear

Other Sources

The Diderot Effect: Why We Want Things We Don't Need

Related Notes

Lifestyle Creep

Hedonic Treadmill