The Diderot Effect

Buying a new road bike can lead to a cascade of new purchases: water bottles, biking shorts, jerseys, gloves, shoes, tools, energy bars and gels...it goes on and on and purchasing the next thing might feel like an obsession. Assembling a collection of bike products enhances the idea of being a cyclist and being part of that world. It’s a satisfying pursuit of being fully immersed into an activity. This phenomenon has been coined the Diderot Effect by cultural anthropologist Grant McCracken.

McCracken turned a story about a French philosopher into a useful tool for thinking about consumer psychology. The story goes like this: in 1765, Denis Diderot, who lived modestly, bought a new robe after coming upon a big sum of money. The beautiful new garment revealed the deficiencies of his other possessions. Diderot wrote that there was “no more coordination, no more unity, no more beauty” among his possessions which started a slew of new purchases.

The Diderot Effect has been widely viewed as negative—an evil force of consumerism that makes us buy things we don’t need. But in many cases, it has a positive effect on people’s lives by reinforcing identity and providing a sense of belonging. For product designers, it’s a useful ideation approach. It invites a thorough exploration of context and meaning, leading designers to imagine “what goes with what?” Or, “how can we help people feel that they’re fully participating in an activity?”