Stress, Health & Disease - Why Zebras Don't Get Ulcers (ch15)

Chapter 15: Personality, Temperament, and Their Stress-Related Consequences

People differ in their ways of modulating stress-responses with psychological variables:

• Style, temperament and personality determine whether you regularly perceive opportunities for control   or safety signals, whether you interpret ambiguous circumstances as implying good news or bad, whether you typically seek out social support etc.

Primates are strongly individualistic and there are astonishing differences in their personalities, temperaments,  and coping styles.

• The lessons learned from some of these animals can be highly relevant to humans
• Baboons:
  • If a male could tell the difference between a threatening and a neutral interaction with a rival, his glucocorticoid levels were twice as low as those who couldn’t tell the difference
  • If the situation is really threatening, those who actively do something about it have less stress than those passively waiting for the enemy’s next move
  • The baboon who can’t tell the difference between winning and losing has much higher glucocorticoid levels
  • Males  with a cluster of low-glucocorticoid traits remain high ranking significantly longer
  • The baboons which are capable of developing friendships have lower cortisol levels

Psychiatric disorders and abnormal stress-responses:

• Half of depressives have resting glucocorticoid levels that are dramatically higher than in other people
• Depressives often don’t even attempt to mount a coping response when facing a stressor
• People prone toward anxiety  overestimate risks and the likelihood of a bad outcome

• The amygdala is overactivated in people with anxiety, therefore ambiguous stimuli are more likely to be seen as threatening.

Type A and cardiovascular diseases

• A trait of type A personality, hostility, is a predictor of heart disease
• The expression of anger is a powerful stimulant of the cardiovascular system
• Hostile people might lack social support
• The hostility component in Type-A can be reduced by therapy and this can lower the risk for further heart disease

Repressive personality and stress

• These people describe themselves as quite happy, they are not depressed nor anxious
• Repressive individuals are planners, who live structured, rule-bound lives
• They desire social approval and don’t like ambiguity – everything has to be black or white, never or always etc.
• They have a peculiar lack of emotional expression
• They have overactive stress responses
• EEG studies show that repressors have unusually high activity in the frontal cortex, which is involved in inhibiting impulsive emotion and cognition

Resources: Sapolsky, R. Why zebras don’t get ulcers: The acclaimed guide to stress, stress-related diseases, and coping. New York (NY): Henry Holt and Company. 2004 3rd edition