Sources of Stress
Some people remain very calm during emergencies; some people feel considerable fear or other strong emotions; and some are terrified by even very minor incidents.
Eysenck suggested that people tending towards the Unstable end of the Neuroticism axis had a problem of ‘sympathetic hyperactivity’ in the amygdala, the hypothalamus and the hippocampus – see Fig 2. These organs in the brain’s sub-cortical limbic system were originally identified by Dr James W Papez as the principal mediators of bodily arousal associated with emotion. More recently the pioneering work of Dr Joseph LeDoux has emphasised the critical responses of the amygdala to alarming sensory stimuli. It stimulates the hypothalamus to create the physiological syndrome we call ‘fight or flight’.
From observations of timidity in domestic cats, Jerome Kagan has put forward the notion that this sympathetic hyperactivity is due to having higher levels of noradrenaline which arouse the amygdala, So, effectively people high in Neuroticism are born with a limbic vicious circle: the amygdala is easily aroused by an excess of noradrenaline; and, when aroused, it stimulates the hypothalamus to make more noradrenaline!