One individual difference as an explanation for stress is personality type: type A, B or C. Type A personality
describes someone who is competitive, time urgent (impatient) and hostile in most situations. Research has
linked this personality type to incidences of coronary heart disease (CHD). Type B personality describes
someone who is laid back, relaxed and tolerant of others in most situations (i.e the opposite of type A
personality). And type C personality describes someone who is compliant, avoids conflict and suppresses their
emotions in most situations. Friedman and Rosenman researched the link between stress related illness and
personality in his study of 3000 men in California. They were assessed as being free of CHD at the beginning
of the study, and they were also assessed for their personality type by asking 25 questions in a structured
interview. The questions concerned their responses to everyday irritations such as having to wait in queues.
The interviews were conducted in a way to incite type A related behaviour in participants e.g the interviewer
would be aggressive and frequently interrupt. Behaviour such as speed talking was observed and measured
which allowed the researcher to class participants as type A or B. The researchers found 8 and a half years
later that twice as many type A’s had died or had cardiovascular problems than type B. Type A’s also had
higher blood pressure and cholesterol than type Bs.
One limitation of research into personality as an individual difference in response to stress is that it is
correlational. Research suggests a relationship between personality and illness but this e.g CVD but this does
not indicate causality. We are not justified in drawing the conclusion that stress causes illness based on
correlational analysis. There may be other causal factors in ilness/ CVD such as diet or exercise. This reduces
the explanatory power of individual differences affecting stress as we cannot establish a cause and effect
relationship. However it could be argued that correlational research is more ethical than conducting an
experiment as studying a relationship between personality and stress is more ethical than purposefully placing
participants under stress.
Another limitation of research is that there are methodological issues. Much of the research uses self report
techniques such as interviews which are subjective and open to interpretation. So the results will not
accurately represent personality type as an individual difference in stress as participants may not consider the
meaning of the questions to be the same which means their answers vary. Participants may demonstrate
social desirability bias by changing their behaving and not answering questions in an entirely truthful way to be
viewed favourably by others and present themselves in a better light e.g type A individuals may appear more
‘laid back’ in front of the interviewer to appear more socially desirable which means personality type cannot be
assessed accurately. This reduces the validity of research into personality types as an individual difference in
stress as it may be measuring the participants willingness to answer questions rather than their personality
type.
A strength of personality types as an individual difference in stress is that there is research support. For
example, Edigo et al studied 150 spanish men and women, under 65 years old, who had a stroke and
compared them with a matched control group. They found that the stroke sufferers were significantly more
likely to have type A personalities, and could not be explained by lifestyle associated risks such as smoking or
diet. This supports personality type as it suggests that type A personality plays a role in cardiovascular
diseases, increasing the validity of personality type as an individual difference in stress.
Discuss Hardiness as an individual difference in stress
One individual difference as an explanation for stress is hardiness, proposed by Kobasa, and it is a set of
personality traits that protect us from stress. Maddi argued that hardiness gives us ‘existential courage’- will
and determination to keep going despite setbacks. There are 3 dimensions to hardiness: commitment,
challenge, and control. Concerning commitment, hardy people are deeply involved in relationships, activities
and themselves. They throw themselves wholeheartedly into life and are optimistic they will learn something
valuable. Challenge is when hardy people are resilient and welcome change as an opportunity or challenge