You could make a very good case for why stress is entirely subjective. The answer all comes down to a basic question: How do you measure stress? Almost ALL stress is measured based on self-reporting. In other words, whether someone says an event is stressful or not. And obviously, that’s entirely subjective.

There are some very official sounding organizations that conduct surveys like the The American Psychological Association (APA) and the Harris Poll, that essentially codify this information making it sound very objective. So, for example, you can go on the APA website and look up statistics on what people find most stressful and you’ll see their annual “Stress in America Survey.”

The APA has been tracking stress in the US for about ten years now and during that entire time job stress and financial stress have ranked 1 and 2 on the list. But this data is entirely based on people’s opinions of what they find to be most stressful.

In her TED TALK, “How to Make Stress Your Friend,” Dr. Kelly McGonigal, a health psychology professor at Stanford, raised quite a stir when she quoted a study that said stress isn't harmful to your health: Only having the belief that stress is harmful is what makes it harmful.

How the researchers that conducted this (retrospective) study arrived at that startling conclusion was a data crunching exercise in parsing out people’s opinions about stress from the 1990’s and then looking up death records from then until now. Of all the people interviewed and self-reported that they were experiencing a lot of stress in their lives - without exception - and we’re talking about thousands of respondents, the only people who died were the ones who also answered YES to the question: Do you believe that stress has had an effect on your health?

So here you have a study - that runs contrary to pretty much everything that has ever been written about stress - that is based on a combination of people’s very subjective opinions about stress PLUS very objective lists of whether they died or not. Dr. McGonigal, who wrote a book entitled THE UPSIDE OF STRESS, built her whole thesis for the book around the idea that subjectivity is the very root cause of the problem we call stress.

But there are some fairly objective ways we can measure stress as well. Biofeedback devices measure all kinds of internal states including: skin temperature, perspiration, heart rate and brainwave frequencies. You can show someone a scary scene from a film and monitor their heart rate or skin temperature, or perspiration and most people’s internal states will change in a predictable way that correlates with their stress.

Cortisol levels are probably the most objective way to measure stress. Cortisol, which is a hormone released into the body during a stressful event, can be measured by taking saliva samples. But there’s one small problem with this mostly reliable way to measure stress. People’s cortisol levels vary throughout the day and the only way to get an approximation of where they should be, is to test them for several days prior to running the experiment.

Sarah Damaske, a professor at Penn State, conducted just such a study. She wanted to find out if work was really more stressful than being at home as most people would surmise if asked. She checked her study participant’s cortisol levels for several days before conducting the experiment.

After establishing a baseline, Dr. Damaske compared levels of cortisol for these subjects when they were home and at work. (Each subject took their own saliva samples at certain times during the day.) Across the board she found that people’s cortisol levels (for the most part) went down when they were at work and were elevated when they got home.

So this last test tells us something very interesting. While most people would subjectively say that work was more stressful than home, in this OBJECTIVE measure of cortisol levels, home turned out to be more stressful than work.

To answer your question. I’d have to say, that for the most part (but not ALWAYS), stress is subjective.

James Porter is CEO of StressStop and author of The Stress Profiler and Stop Stress This Minute. He also has presented seminars on stress management for The CIA, The FBI, Time Life, Blue Cross Blue Shield and The American Heart Association.