The core lesson: people value what they help build — but only when it actually works The IKEA effect captures a simple but powerful truth: we tend to value things more when we’ve had a hand in making them. In the original research by Norton, Mochon, and Ariely, people valued self-assembled products more highly than identical pre-built ones. But there was an important catch: the effect weakened—or even disappeared—when the work was unsuccessful, incomplete, or undone. Put simp