Individual Differences in Stress

The Physical Effects of Stress

The negative health outcomes of stress are due to the physiological processes that the stress response involves. Two physiological responses are triggered in response to a stressor; these consist of the activation of:

• The Sympathomedullary pathway and,
• The Hypothalamic Pituitary Adrenal (HPA) Axis.

This response involves a release of adrenaline and noradrenaline, which increases breathing, heart rate, blood pressure and glucose concentration in the bloodstream to quickly deliver energy to our muscles.

Functions unrelated to fighting or fleeing from a predator, including digestion, immune and reproductive functions, are put on hold.

Cortisol has similar effects to adrenaline but acts for longer. It increases the amount of glucose in the bloodstream and blood pressure and puts digestion, immune and reproductive functions on hold.

Individual Differences in Stress Response

Researchers have observed that some people respond to stress differently than others. Early work in this domain was conducted by cardiologists Friedman and Rosenman, who investigated individual predisposition towards Coronary Heart Disease (CHD) in the 1960s. The researchers established two main personality types: A and B, with type A personality identified as predisposing people to greater CHD risk.

Kissen & Eyesneck (1962) also suggested Type C personality, which was further explored by Temoshok (1987) as part of her integrative model of traits related to cancer.

Below are three personality types with their associated behaviours.

The Different Reactions to Stress

People with Type A personalities might put a lot of pressure on themselves regarding work and success. They might work around the clock and feel like they are always running out of time; they prioritise work over other social activities or hobbies. They are likely to feel more threatened by change, get irritated quickly, and have a hostile or mistrustful attitude towards others.

Type B has a more flexible attitude to work, success and change. Work is not prioritised above all else for them, so it's not the end of the world for them if they don't reach their goals. Their attitude to others allows them to cultivate supportive relationships.

Type C's combine the passion and motivation of Type A without the urgency and hostility. They might feel helpless when faced with stressful situations, struggle to reach for support, suppress their emotions and focus on the needs of others instead of their needs.

Fig. 2 - Type A's are competitive and determined; they tend to have a hostile and mistrustful attitude towards others.

Personality and Stress: Individual Differences in the Stress Process

Early evidence suggests that type A personality is at a greater risk of developing Coronary Heart Disease when exposed to stress compared to type B personality. While type C personality was linked to a greater risk of cancer.

Individual Differences in Stress: Type A Personality Health Outcomes

Friedman and Rosenman (1974) examined the relationship between stress-related illness and personality types. They conducted a longitudinal study with 3200 male participants from San Francisco, aged 39 to 59. All participants were healthy at the beginning of the study.

Participants were categorised as Type A or B based on their behaviour during an interview. These interviews were designed to capture the trait of hostility associated with Type A's. Researchers performed scripted actions during the interview, such as interrupting the participant or being aggressive towards them.

When researchers followed up with participants after eight years, they found 257 participants suffered from coronary heart disease, 70% of whom were personality type A. High blood pressure and high cholesterol levels were more likely to be observed in type A than B.

Individual Differences in Stress: Type C Personality Health Outcomes

Dattore et al. (1980) examined the relationship between personality types and stress-related illness. The participants included 200 retired army personnel who had served in the Vietnam War. They completed a questionnaire measuring depression symptoms and suppression of feelings.

At follow-up, 75 participants developed cancer. These participants showed fewer depression symptoms but greater repression of feelings.

To conclude, this study supports an association between Type C stress response (repression of feelings) and cancer.

Individual Differences in Stress: Hardiness in Psychology

So, traits like hostility and emotional suppression can increase one's risk of diseases, but are there any traits that protect people from negative health outcomes related to stress?

Kobasa and Maddi (1979) proposed the three C's associated with hardiness. These traits act as a defence system against the adverse effects of stress.

Hardy people strive for growth in the face of difficult times and view stressful situations as a challenge to overcome a difficult situation rather than an obstacle.

Fig. 3 - Hardiness can make people more resilient to the negative effects of stress.

Individual Differences in Stress: Kobasa and Maddi's (1979) Research Study

Kobasa et al. (1979) conducted a longitudinal study of 800 male American executives. They aimed to study the effects of stress on a sample of executives who face highly stressful events at work.

They used the SRRS (Social Readjustment Rating Scale) to measure stress levels and asked subjects about previous episodes of illness or disease.

Approximately 150 participants had high SRRS scores, indicating a history of high stress. Of these participants, 75 reported more illness, while 86 reported less illness.

Researchers followed up with participants after three months and administered personality tests, including a measure of hardiness.

• The participants with low levels of illness scored high on all three hardiness traits.

• The participants with high levels of illness scored low on all three hardiness traits.

These results suggest that hardiness could buffer the effects of stress in the low-illness group.

Researchers suggested that people can learn hardiness through therapy and hardiness training that change people's outlook on stress and life's challenges. This is an example of practical applications of hardiness research.

However, the findings might not generalise to women, non-American samples and people from other socio-economic classes.

Individual and Cultural Differences in Stress

Cultural differences can also influence the extent to which stress affects us. Firstly, across cultures, people are exposed to different types of stressors.

Depending on one's culture, we also perceive and appraise stressors differently.

Culture affects how we cope with stressors. In some cultures, individuals may rely on their social support or spirituality to cope with stress, while in others, independent and problem-oriented coping may be preferred.

Some evidence also points to the fact that some cultures are more prone to stress-related illness due to physiological factors. We see much higher levels of high blood pressure and coronary heart disease in African Americans than in European Americans. This could be both due to environmental and biological differences.