Kobasa's Hardiness Theory: Stress, Personality, and Health

Introduction and Research Context

Suzanne Kobasa's Personality and Social Psychology article, "Stressful Life Events, Personality, and Health: An Inquiry into Hardiness," builds upon past research to examine individual and group differences in responses to stressful life events. The author provides extensive reviews of prior literature, pointing out the limitations that led her to conduct the current study. Much of this literature had already established a correlation between stressful life events and physical illness — specifically, that "stressful life events precipitate somatic and psychological disease" (Kobasa 1979, p. 1). Because prior research had shown that "the recent life histories of hospitalized persons contain significantly more frequent and serious stressful events than do histories of matched controls from the general population," Kobasa designed her study to discover which personality factors were most significant in determining how a person reacts to stressful events.

Kobasa clearly defines her terms and her hypotheses. Based on findings from prior researchers, she chose to study one variable in particular — personality — as it relates to the relationship between stress and physical illness. Studies had shown that many highly stressed individuals do not exhibit physical illness, and Kobasa concluded that subjects who do not get ill are the ones most often overlooked. She discovered that the research suggests individuals who demonstrate a personality defined by hardiness are less likely to develop illnesses following stressful life events. Hardiness is defined by three key characteristics: an internal locus of control, a strong sense of commitment, and an appreciation of change as a positive force.

Defining Hardiness and the Study Hypothesis

In accordance with the existing research, Kobasa defines stress as a life event that "causes changes in, and demands readjustment of, an average person's normal routine" (p. 2). Stressful events can be "positive," such as marriage, or "negative," such as the death of a loved one. Kobasa's hypothesis is divided into three key components:

a) "Among persons under stress, those who have a greater sense of control over what occurs in their lives will remain healthier than those who feel powerless in the face of external forces" (Kobasa 1979, p. 3);

b) "Among persons under stress, those who feel committed to the various areas of their lives will remain healthier than those who are alienated" (Kobasa 1979, pp. 3–4);

Methodology and Sample Population

c) "Among persons under stress, those who view change as a challenge will remain healthier than those who view it as a threat" (Kobasa 1979, p. 4).

The population of interest for Kobasa's study is limited to individuals who report a high number of stressful life events occurring over the previous three years. Kobasa used the Schedule of Recent Life Events, designed by Holmes and Rahe in 1967. This instrument asks whether subjects have experienced events of major consequence — both positive and negative — such as marriage, illness, death, divorce, and childbirth. The researcher then administered a second questionnaire to measure illness severity. Only those subjects whose illnesses followed the stressful events were categorized as high stress/high illness.

Following the intake questionnaires, Kobasa narrowed her population to include only male executives working for a particular corporation who had experienced significant stress over their recent life histories. These highly stressed individuals were then divided into two groups: high illness and low illness. The purpose of the study was to explore the differences between high stress/high illness and high stress/low illness persons. The three variables used to determine hardiness — control, commitment, and challenge — were measured by self-report questionnaires. Kobasa employed discriminant function analysis as the primary statistical technique and also used test and cross-validation procedures to improve the reliability of her results.