Experiment 1A: Participants either inspected an IKEA pre-built box or assembled it themselves. Afterward, they were asked to bid on the box they had either seen or built. If their bid was above a random number, they would pay that amount to keep the box; if it was lower, they couldn’t keep it. Participants were also asked to self-report on the value of the box. An effect was found in both cases; on average, participants bid 62% more when they built the box versus when they simply inspected it. On average, participants also self-reported liking the self-built box more than the inspected boxes.
Other experiments used origami creations and LEGO sets, and the same effect was noted. Read more about it at NeoAcademic. Link -via Boing Boing
I'd like to see the data normalized to dollars to per hour to see exactly how much value they placed on their time.
Future intelligent species (speculation) will probably be looking at the moon and wondering; how the f*ck did that get on there???