Workplace Stress

Personality and Stress: Type A Behaviour Pattern

Individual differences in personality are associated with differences in both the appraisal of stressors and the physiological stress response, with significant consequences for long-term health. The Type A behaviour pattern is the most extensively studied personality-stress-health link.

Type A and Type B Behaviour Patterns

Friedman and Rosenman (1959, 1974), two cardiologists, observed that many of their heart disease patients shared a distinctive behaviour pattern. They described two contrasting types:

Type A behaviour pattern (TABP): characterised by competitive drive, time urgency (constantly feeling pressed for time, impatient), hostility and irritability, tendency to engage in multiple tasks simultaneously, rapid speech, and intense achievement motivation. Type A individuals create their own stress — they set demanding goals, interpret situations as competitive, and respond to obstacles with hostility and frustration.

Type B behaviour pattern: characterised by a more relaxed, easy-going approach — non-competitive, patient, able to work without time pressure or distress. Type B individuals are not less ambitious but do not exhibit the urgency, hostility, or competitive anxiety of Type A.

The classification was originally made using a Structured Interview — a standardised, mildly confrontational interview designed to elicit competitive and hostile responses — with assessment of speech style, latency, and content.

The Western Collaborative Group Study (WCGS)

Rosenman et al. (1975) conducted the landmark Western Collaborative Group Study — a prospective study of approximately 3,000 healthy California men aged 35–59, assessed at baseline for Type A/B classification using the Structured Interview. Participants were followed for 8.5 years and monitored for coronary heart disease (CHD). Men classified as Type A at baseline were approximately twice as likely to develop CHD during the follow-up period as Type B men, even after controlling for established cardiovascular risk factors (blood pressure, cholesterol, smoking). This landmark finding established Type A as an independent risk factor for CHD.

Physiological Mechanism

Type A individuals show greater cardiovascular reactivity to stressors — more pronounced elevations in blood pressure, heart rate, and cortisol in response to competitive or frustrating situations. Chronically elevated adrenaline and cortisol, repeated across many stressful encounters, contribute to atherosclerosis (arterial plaque formation), hypertension, and endothelial damage — the physiological mechanisms underlying CHD. Type A individuals also exhibit elevated fibrinogen levels (a clotting factor), increasing thrombosis risk.

The 'Toxic Component': Hostility

Subsequent research questioned whether the entire Type A pattern was pathogenic, or only specific components. Booth-Kewley and Friedman (1987) conducted a meta-analysis and found that hostility and anger — rather than time urgency or competitiveness per se — were the most consistent predictors of CHD. Miller et al. (1996) confirmed that cynical hostility specifically (distrust and resentment of others' motives) is the 'toxic component' of the Type A pattern. This has been important for both theoretical understanding and intervention — reducing hostility is a more specific and achievable treatment target than the broad Type A pattern.

Evaluation

The WCGS was a large, prospective, well-controlled study. However, later large-scale studies (MRFIT; Multiple Risk Factor Intervention Trial) failed to replicate the Type A-CHD relationship, and some re-analyses of WCGS data using independent raters also failed to confirm it. This inconsistency suggests that the relationship may be weaker or more conditional than initially claimed — moderated by the specific assessment method used (Structured Interview vs questionnaire) and by which component of Type A (particularly hostility) is measured.