All work and no play may just be a result of “mindless accumulation.”

So say scholars behind research, published in the journal Psychological Science in June, that shows a deeply rooted instinct to earn more than can possibly be consumed, even when this imbalance makes us unhappy.

Given how many people struggle to make ends meet, this may seem a frivolous problem. Nonetheless, the researchers note that productivity rates have risen, which theoretically lets many people be just as comfortable as previous generations while working less. Yet they choose not to.

To explore the powerful lure of material accumulation, the researchers constructed an experiment in two phases. In the first phase, subjects sat for five minutes in front of a computer wearing a headset, and had the choice of listening to pleasant music or to obnoxious-sounding white noise.

They were told they could earn pieces of Dove chocolate when they listened to the white noise a certain number of times. Some participants had to listen fewer times to get each piece of chocolate, making them “high earners”; some had to listen more times, making them “low earners.”