What Is Stress?

THE PREVALENCE OF STRESS

Stress is everywhere and, as shown in Figure, it has been on the rise over the last several years. Each of us is acquainted with stress—some are more familiar than others. In many ways, stress feels like a load you just can’t carry—a feeling you experience when, for example, you have to drive somewhere in a crippling blizzard, when you wake up late the morning of an important job interview, when you run out of money before the next pay period, and before taking an important exam for which you realize you are not fully prepared.

A pie chart is labeled “Change in Stress Levels Over Past 5 Years” and split into three sections. The largest section is labeled “Increased” and accounts for 44% of the pie chart. The second largest section is labeled “Stayed the same” and accounts for 31% of the pie chart. The smallest section is labeled “Decreased” and accounts for 25% of the pie chart.
Nearly half of U.S. adults indicated that their stress levels have increased over the last five years (Neelakantan, 2013).

Stress is an experience that evokes a variety of responses, including those that are physiological (e.g., accelerated heart rate, headaches, or gastrointestinal problems), cognitive (e.g., difficulty concentrating or making decisions), and behavioral (e.g., drinking alcohol, smoking, or taking actions directed at eliminating the cause of the stress). Although stress can be positive at times, it can have deleterious health implications, contributing to the onset and progression of a variety of physical illnesses and diseases (Cohen & Herbert, 1996).

The scientific study of how stress and other psychological factors impact health falls within the realm of health psychology, a subfield of psychology devoted to understanding the importance of psychological influences on health, illness, and how people respond when they become ill (Taylor, 1999). Health psychology emerged as a discipline in the 1970s, a time during which there was increasing awareness of the role behavioral and lifestyle factors play in the development of illnesses and diseases (Straub, 2007). In addition to studying the connection between stress and illness, health psychologists investigate issues such as why people make certain lifestyle choices (e.g., smoking or eating unhealthy food despite knowing the potential adverse health implications of such behaviors). Health psychologists also design and investigate the effectiveness of interventions aimed at changing unhealthy behaviors. Perhaps one of the more fundamental tasks of health psychologists is to identify which groups of people are especially at risk for negative health outcomes, based on psychological or behavioral factors. For example, measuring differences in stress levels among demographic groups and how these levels change over time can help identify populations who may have an increased risk for illness or disease.

Figure depicts the results of three national surveys in which several thousand individuals from different demographic groups completed a brief stress questionnaire; the surveys were administered in 1983, 2006, and 2009 (Cohen & Janicki-Deverts, 2012). All three surveys demonstrated higher stress in women than in men. Unemployed individuals reported high levels of stress in all three surveys, as did those with less education and income; retired persons reported the lowest stress levels. However, from 2006 to 2009 the greatest increase in stress levels occurred among men, Whites, people aged 45–64, college graduates, and those with full-time employment. One interpretation of these findings is that concerns surrounding the 2008–2009 economic downturn (e.g., threat of or actual job loss and substantial loss of retirement savings) may have been especially stressful to White, college-educated, employed men with limited time remaining in their working careers.

Graphs a through f show mean stress scores in 1983, 2006, and 2009, and how they have been impacted by different factors. Graph a shows the relationship between mean stress score and sex. The mean stress score for men steadily increased from 12 in 1983 to a little over 14 in 2006 to a little over 15 in 2009. The mean stress score for women increased rapidly from a little under 13 in 1983 to 16 in 2006 and remained the same in 2009. The graph indicates that the mean stress score for women is higher than the mean stress score for men overall. Graph b shows the relationship between mean stress score and age. The mean stress scores for people under 25 years old increased from a little over 14 in 1983 to a little over 18 in 2006, and then decreased to 17 in 2009. The mean stress scores for people 25 to 34 years old increased from a little under 14 in 1983 to 18 in 2006, then decreased to a little over 16 in 2009. The mean stress scores for people 35–44 years old increased from 13 in 1983 to a little under 17 in 2006, then decreased to a little over 16 in 2009. The mean stress scores for people 45–54 years old from a little under 13 in 1983 to 15 in 2006, then increased to a little under 17 in 2009. The mean stress scores for people 55–64 years old steadily increased from 12 in 1983 to a little over 13 in 2006 to a little over 14 in 2009. The mean stress scores for people 65 years old or older decreased from 12 in 1983 to a little under 11 in 2006, then slightly increased to 11 in 2009.  Graph c shows the relationship between mean stress score and race. The mean stress scores for White people steadily increased from a little under 13 in 1983 to 15 in 2006 to a little over 15 in 2009. The mean stress scores for Black people increased from a little over 15 in 1983 to a little over 16 in 2006, then slightly decreased to a little over 15 in 2009. The mean stress scores for Hispanic people steadily increased from 14 in 1983 to a little under 16 in 2006 to 17 in 2009. The mean stress score for people classified as “Other” increased from 14 in 1983 to a little over 17 in 2006 where it remained. Graph d shows the relationship between mean stress scores and education. The mean stress scores for those with less than a high school education steadily increased from a little over 14 in 1983 to a little over 17 in 2006 to 19 in 2009. The mean stress scores for those with a high school education increased from 12 in 1983 to a little over 16 in 2006 and remained the same in 2009. The mean stress scores for those with some college education increased from 12 in 1983 to a little over 15 in 2006, then slightly increased to a little under 16 in 2009. The mean stress scores for those with a bachelor’s degree steadily increased from 12 in 1983 to a little over 13 in 2006 to 15 in 2009. The mean stress scores for those with advanced degrees also steadily increased, from a little over 11 in 1983 to 13 in 2006 to a little under 15 in 2009. Graph e shows the relationship between mean stress scores and employment status. The mean stress scores for those with full time employment status steadily increased from a little over 12 in 1983 to 15 in 2006 to 16 in 2009. The mean stress scores for those with part time employment status increased from 14 in 1983 to 16 in 2006, then decreased to 15 in 2009.The mean stress scores for those who were unemployed rapidly increased from a little over 16 in 1983 to 20 in 2006, then decreased back to a little over 16 in 2009. The mean stress scores for those who were retired remained lower than the other groups, remaining at a little under 12 in 1983 and 2006, then slightly increasing to a little over 12 in 2009. Graph f shows the relationship between the mean stress score and income in U.S. dollars. The mean stress scores for those with an income of $25,000 or lower steadily increased from a little over 15 in 1983 to 17 in 2006 to a little under 18 in 2009. The mean stress scores for those with an income of  $25,001 to $35,000 steadily increased from 14 in 1983 to 16 in 2006 to a little under 17 in 2009. The mean stress scores for those with an income of $35,001–$50,000 steadily increased from a little under 13 in 1983 to a little over 15 in 2006 to a little over 16 in 2009. The mean stress scores for those with an income of $50,001–$75,000 increased rapidly from 12 in 1983 to a little under 15 in 2006, then slightly increased to a little over 15 in 2009. The mean stress scores for those with an income of $75,001 or more steadily increased from 12 in 1983 to a little under 13 in 2006 to a little over 14 in 2009.
The charts above, adapted from Cohen & Janicki-Deverts (2012), depict the mean stress level scores among different demographic groups during the years 1983, 2006, and 2009. Across categories of sex, age, race, education level, employment status, and income, stress levels generally show a marked increase over this quarter-century time span.