Modern neuroscience has strongly suggested that optimism might benefit physical health, and researchers are now confirming that psychoemotional stress might actually trigger physical inflammation in the body. Even back in 1934, they knew that the key to mastering life was the elimination of worries. F. Scott Fitzgerald set out to immunize his daughter Scottie against stress with an itemized list of the things in life to worry and not worry about. But what, exactly, is stress — and how did we come to think of it the way we do?

In One Nation Under Stress: The Trouble with Stress as an Idea (public library), Dana Becker investigates the origins of our stress metaphors:

Stress has had many different meanings over the centuries, and because of this, the way we talk about ‘stress’ now bears only a shadow of a resemblance to the way people talked about stress long ago. At one time, stress was a name for ‘what was hard and had to be endured,’ as Robert Kugelmann has noted. Stress demanded strength and fortitude. The image that was often invoked was that of a ship tossed about by the stress of bad weather, and in that image Kugelmann sees the difference between the stress of then and the stress of now. The storm-tossed ship represented something that neither challenged the forces outside it nor was wholly separate from these forces. Stress was what ‘proved the strength, power, and virtue of the ship and crew.’ It was occasional, like wintery blasts that assailed that metaphorical ship; stress signified hardship, and endurance was needed to deal with it. Now, particularly in the middle class, we ‘work’ to overcome stress; we don’t suffer it. And stress is not considered a sometime thing in contemporary Western societies; it is believed to be constant.

Much like our early metaphors for memory, which likened the mind to the recording technologies of yore, Becker traces the metaphor for stress to yesteryear’s depictions of the body as a machine and an industrial apparatus:

Early engineering gave us the ideas of stress and strain, and from these followed the metaphor of the body as a machine with a finite store of energy and with parts that life could grind down. The 1949 edition of the Merriam Webster Collegiate Dictionary defined stress completely without reference to human beings, as the ‘action of external forces; especially to overstrain.’; Today, the definition reads like this: ‘a physical, chemical, or emotional factor that causes bodily or mental tensions and may be a factor in disease causation’ and ‘a state from a stress; especially one of bodily or mental tension resulting from factors that tend to alter an existent equilibrium.’ Stress now derives from physics, where it refers to the force that can transform material in ways that cause it to change its form or to break. In our vernacular, stress can be both a cause (‘It was stress that caused his heart attack’) and effect (‘When the plane was late I was so stressed out’). But although we refer to stress as both a force outside the person and an inner state, recently it is the inner state that has been getting the primary emphasis.

This inward reorientation of the stress metaphor, Becker argues, is largely the result of the rising monoculture of liberal individualism, which places individual freedom and self-actualization at the heart of what it means to be human, all the while preserving and honoring the fluid self and negating the myth of fixed personality:

The ‘self’ has become something we can think and talk about — something we can even remake, if necessary. But individualism or no, the self is not separate from social expectations and norms; it can’t be considered apart from the way it is talked about and judged, as British psychologist Nikolas Rose has pointed out. Many of the events in our lives (marriage, unemployment, combat) are open to judgments about how we have coped with or adjusted to them, and these judgements are steeped in a psychological language that has slipped its middle-class moorings to become the currency of our time. … [At] other times in our history, when the stress concept didn’t exist, we couldn’t experience ourselves in the way that stress both describes and delimits.

In the rest of One Nation Under Stress: The Trouble with Stress as an Idea, Becker, a professor of social work at Bryn Mawr College, goes on to argue that the concept of stress has become inflated to a deleterious degree over the past 40 years, critiquing our cultural tendency to approach stress management and the preservation of sanity as a matter of perpetual bandaging of symptoms rather than a deeper concern with understanding and healing the underlying causes.