Measuring Stress (AQA A-Level Psychology): Revision Notes

Measuring Stress

Psychologists need reliable and valid methods to measure stress before they can understand its relationship with illness. There are substantial real-life benefits from understanding this connection, which has led to the development of two main categories of measurement: self-report methods and physiological methods.

Self-report measures

Self-report measures allow participants to describe their own stress levels through questionnaires and checklists. These methods rely on individuals' subjective experiences and interpretations of stressful events.

Social readjustment rating scale (SRRS)

The Social Readjustment Rating Scale was developed by Holmes and Rahe (1967) as a checklist to measure stress from major life changes. The researchers examined medical records of thousands of hospital patients and identified 43 life events that commonly occurred before people became ill.

The scale works by asking participants to indicate which life changes they have experienced over a specific time period (typically 12 months). Each event is assigned a numerical value called Life Change Units (LCUs), which reflects the degree of readjustment needed to cope with that change.

To create these values, Holmes and Rahe asked several hundred participants to rate how much readjustment each life change would require, using marriage as a reference point of 500 units. They then calculated average scores and divided by ten to create the final LCU values. Participants' individual scores are calculated by adding up the LCUs for all events they have experienced.

Hassles and uplifts scale

Kanner et al. (1981) argued that daily hassles and uplifts might be better indicators of stress than major life events. They developed the Hassles and Uplifts Scale to measure these everyday experiences.

The Hassles Scale contains 117 items covering everyday irritations across seven categories: work, health, family, friends, environment, practical considerations, and chance occurrences. Examples include troublesome neighbours, too much responsibility, disliking work colleagues, and planning meals. Participants rate the severity of each hassle on a three-point scale.

The Uplifts Scale was constructed similarly, containing 135 items measuring small everyday pleasures from the same categories. Examples include getting enough sleep, liking fellow workers, and meeting responsibilities. Participants indicate which uplifts they have experienced and how often over a specified time period.

Physiological measures

Physiological measures record the body's biological responses to stress, providing objective data about stress levels without relying on self-reporting.

Skin conductance response (SCR)

The skin conductance response measures stress through the body's electrical conductivity. This method is based on the fight-or-flight response - when we experience stress, the autonomic nervous system becomes aroused, causing increased sweating. Since human skin conducts electricity well, more sweating leads to greater electrical conductance.

To measure SCR, electrodes are attached to the index and middle fingers of one hand. A tiny electrical current is applied and the conductance is measured in microSiemens, then amplified and displayed on a screen.

SCR is often used alongside other physiological measures like heart rate and blood pressure to create a polygraph. On television programmes like the Jeremy Kyle Show, this is commonly known as a "lie detector test."

Evaluation

Validity issues

Self-report stress measures face problems with validity because many items are general categories rather than specific events. Research by Dohrenwend et al. (1990) showed that participants interpret items very differently.

This intracategory variability creates validity problems because people experiencing high stress tend to place the most negative interpretations on items. This makes it difficult to assess the true relationship between stress, life events, and illness.

The contamination effect

Both the SRRS and Hassles Scale were designed to predict stress-related illness, but many items overlap with symptoms of physical and psychological disorders. Items like 'personal injury or illness' on the SRRS and 'hospitalisation' on the Hassles Scale may reflect illness rather than predict it.

Individual differences in SCRs

SCR measurement accounts for individual differences in baseline skin conductance by taking a tonic conductance measure before presenting any stimulus. However, individual differences extend beyond this basic consideration.

Some people are stabiles - their SCRs vary little when at rest and are not heavily influenced by internal thoughts or external events. Labiles, however, produce many SCRs even when resting. This means SCR measurement is not simply a matter of comparing baseline against stimulated responses. Failure to account for these participant differences threatens the validity of research studies using SCRs to measure stress.

Global versus specific measures

The SRRS and Hassles and Uplifts Scale are global measures that provide a single score combining many different aspects of stressors. The assumption is that one stress measure can predict any kind of illness. However, it makes more sense to assume there are specific types of life changes or hassles that may predict particular illnesses.

Controllable versus uncontrollable events

Research by Stern et al. (1982) found that when participants completed the SRRS and indicated which items they believed were controllable versus uncontrollable life changes, only the uncontrollable life changes were reliable predictors of later physical illness. The controllable changes were not predictive.