

Looking at the four personality types depicted in the graphic above, which most accurately describes you? By 'you', we mean the natural you, the you you don't have to work at, the you which feels most comfortable to you when there are no pressures to be anyone else.
We're talking about the you you were born with: your natural temperamental type.
Of course, very, very few people remain totally true to that type in all circumstances
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How much you are any one type will depend on where you tend to locate naturally on each of the 2 Dimensions of Neuroticism (Instability) and Extraversion. A number of studies have supported Hans J Eysenck’s (1967) contention that our default position on these Dimensions is birthed in us. One of the most notable of these is that of John C Loehlin (1992) who found, in monozygotic (MZ) twins reared together correlations for Extraversion of 0.51 and Neuroticism of 0.46; in MZ twins reared apart Loehlin found correlations of 0.38 for both Extraversion and Neuroticism, suggesting differing environments made only small differences compared to the effects of being genetically identical.
However, most people can and do move along these axes, according to circumstances and especially if those circumstances require a vMEME shift. Though it will take considerable regular reinforcement, people can be conditioned by either positive reward or positive punishment to behave substantially different to natural type. However, as William Moulton Marston (1928) pointed out when considering how and why behavioural traits shift, there is always a natural tendency to revert to type when under severe pressure.
The concept of Phlegmatic, Choleric, Melancholic and Sanguine temperamental types
has its roots in the ancient Greek medical philosophy of the 4 Humours, popularised
in the writings of the 2nd Century Roman physician Claudius Galen. Such is the accuracy
of this typing system that it has stood the test of time and has been given a scientific
basis -
Neuroticism & Extraversion
It was in 1947 that Eysenck factor-
Eysenck attributed position along the Extraversion axis to the level of electrical stimulation in the cerebral cortex from the ascending reticular activating system (ARAS). The main function of the ARAS is to maintain an optimum level of alertness or ‘arousal’. It does this by enhancing the incoming sensory data to the cortex through the excitation of neural impulses or it can damp them down. In extraverts the ARAS causes inhibition which reduces the intensity of sensory stimulation reaching the cortex. For introverts the ARAS builds up excitation which increases the intensity of sensory information reaching the cortex. The result of this is that introverts have a lot of internal activity and, therefore, seek a 'quiet life' to avoid further, external stimulation whereas extraverts are proverbial 'emptyheads' who seek external stimulation to fill the void inside.
In 1965 Eysenck wrote: “The typical introvert is a quiet, retiring sort of person,
introspective, fond of books rather than people; he is reserved and distant except
to intimate friends....He does not like excitement, takes matters of everyday life
with proper seriousness and likes a well-
The typical extravert is sociable, likes parties, has many friends, needs to have
people to talk to and does not like reading or studying by himself. He craves excitement...is
carefree, easy-

temper easily; altogether his feelings are not kept under tight control and he is not always a reliable person.”
Neuroticism -
Eysenck attributed the sympathetic branch of the autonomic nervous system (ANS) as
reacting to a highly-
Eysenck (1965) describes the typical high N scorer as “...an anxious, worrying individual,
moody and frequently depressed; he is likely to sleep badly and to suffer from various
somatic disorders. He is overly emotional, reacting too strongly to all kinds of
stimuli and finds it difficult to get back on an even keel after each emotionally-
The low N scorer “...tends to respond emotionally only slowly and generally weakly
and to return to baseline quickly after emotional arousal; he is usually calm, even-
Hans J Eysenck

Graphic copyright © 1999-

Types & Traits
Eysenck’s Dimensions -
Below the traits are the habitual responses -
The structure of Eysenck’s hierarchy is shown left and applied to Introversion and Extraversion below.
Since the original 1947 study, E and N have been found in a number of studies replicating Eysenck’s findings.
There have also been findings with implications for those who deal with people who are strongly introverted and extroverted.
Steve Harkins & Russell Green (1975) found that introverts were significantly better at vigilance tasks which require prolonged periods of intense concentration. However, extraverts were more likely to try to change an unsatisfactory situation. Eysenck (1970) discovered that introverts had lower pain thresholds while extroverts were more susceptible to the adverse effects of sensory deprivation. Working with his son, Michael, Eysenck (1985) found that extraverts were more likely to change jobs and sexual partners more frequently, more likely to divorce, show less brand loyalty in shopping behaviour and move house more often.
Interestingly, in an unpublished study by N N Trauel (1961), reported in Hans Eysenck
(1967), extraverts were shown to have more difficulty conforming to instructions
because they felt the need to express themselves. This may be evidence that strong
extraverts may favour the self-
