The expression hedonic treadmill was coined in 1971 by psychologists P. Brickman and D. Campbell, and the concept is also sometimes known as the hedonistic treadmill or hedonic adaptation. The adjectives hedonic/hedonistic relate to the idea of (continually pursuing) pleasure, and are often associated with temporary sources of happiness like new purchases, which initially give you a sense of well-being but then lose their appeal over time. The word treadmill dates back to the early 1800s and in its literal sense describes a piece of equipment that you walk or run on whilst staying in the same position. Though today the word treadmill usually conjures up images of high-tech machines for improving fitness, treadmills were originally used as disciplinary instruments in prisons. The word’s use in hedonic treadmill is based on its common metaphorical reference to a situation which is frustratingly boring, repetitive and has no long-term benefits.