As recently as the 1950s, there was little research to suggest that illnesses like CHD could be affected by psychological factors. Friedman and Rosenman (1959) carried out research in this area, considering two different personality types: Type A competitive, hostile, restless, pressured, Type B
Opposite to Type A, relaxed and laid back.
Longitudinal Study, Self Selected Sample, 3,200 Californian men, All aged between 39 and 59, All healthy to begin with, 8.5 years assessment period, Structured interview & observing.
In addition, interviews and observations were used to assess personality type and health status
Personality type in particular was interesting, as to assess whether someone was Type A required the interviewer to:
Interrupt participants deliberately
Look for signs of impatience (like finger tapping)
On the basis of this interview, participants were assessed as: A1 – Type A, A2 – Not fully Type A, X – Equal amounts of A/B, B – Type B.
Part 2 of the study was to follow up 8.5 years later to see if CHD had developed. 3,200 > 257 > 70% > x2 > Even when accounted for Adrenaline, Noradrenaline and Cholesterol.