Revise Measures of stress for Cambridge 9990 (3.4.2)

Measuring stress is fundamental to understanding its impact on health and behaviour. Psychologists use two primary categories of measurement: self-report scales and physiological indicators. Self-report measures capture an individual's subjective experience, asking them to reflect on their feelings and the events they perceive as stressful. In contrast, physiological measures provide objective data by recording the body's automatic biological responses to a stressor, such as changes in heart rate or hormone levels. As stress is a complex psychophysiological phenomenon, neither method is perfect on its own. Researchers often employ a combination of both approaches, a practice known as triangulation, to achieve a more valid and comprehensive assessment of an individual's stress levels and their effects.

A classic self-report tool is the Social Readjustment Rating Scale (SRRS), developed by Holmes and Rahe (1967). It is based on the hypothesis that major life events requiring significant social readjustment are a primary source of stress. The scale consists of 43 life events, each assigned a 'Life Change Unit' (LCU) score based on the perceived level of adjustment required. Participants tick the events they have experienced over a set period (e.g., 12 months), and their LCU scores are totalled. A high score is positively correlated with an increased likelihood of future illness. However, the scale is criticised for being correlational, not causal, and for failing to account for individual differences in how an event is perceived and managed.

As a counterpoint to the focus on major life events, Kanner et al. (1981) proposed that the cumulative effect of minor, everyday stressors—or 'daily hassles'—is a more significant predictor of poor health. They developed the Hassles and Uplifts Scale. The Hassles Scale lists common irritants like 'losing things' or 'traffic jams', which participants rate for severity. The Uplifts Scale measures positive daily events, such as 'getting on well with colleagues', which may buffer the negative effects of stress. Kanner's research found that the severity of daily hassles was a better predictor of psychological symptoms, like anxiety and depression, than the LCU scores from the SRRS, highlighting the importance of chronic, low-level stress.

Physiological measures assess the body's involuntary response to stress, providing objective data. These methods target the two main stress pathways. The Sympathomedullary (SAM) pathway, responsible for the 'fight or flight' response, can be measured via heart rate, blood pressure, and the Galvanic Skin Response (GSR). The GSR measures changes in the skin's electrical conductivity caused by sweating. The Hypothalamic-Pituitary-Adrenal (HPA) axis, associated with chronic stress, is assessed by measuring levels of the hormone cortisol. This can be done through samples of saliva, blood, or urine. While these measures are scientific and avoid subjective bias, they can be invasive, expensive, and the results can be confounded by other factors like caffeine, exercise, or the stress of the measurement procedure itself.