Personality Scales for Intelligent Adults

© 2003-2012 Paul Cooijmans

Explanation of the scales

The P.S.I.A. comprise twelve scales, two of which, Introverted and Neurotic, are well known from other tests and considered fundamental personality factors, while the remaining ones are experimental and subject to research. There are also three factors called Deviance, Ethics, and System, which are derived from the twelve basic scales by combining scales that intercorrelate well (tend to go together, form a cluster). Attempts are being made to use some of the scales to obtain measures of conscientiousness and associative horizon, two of the components of creativity and genius.

The below image aims to give an impression of the Deviance dimension; there is increasing Deviance from the bottom to the top of the image.

The Deviance dimension

The distribution of the P.S.I.A. items over the eleven scales other than Extreme is based on statistical item analysis; each item counts toward the scale with which it has its largest correlation either positive or negative, while a small number of inconclusive items are not used for any of these eleven scales (the Extreme scale uses all of the items). This statistical process of assigning items to scales is blind with regard to the items' contents and therefore free of subjective bias. This method is needed as test items often behave in ways different from what one would intuitively expect. This is so because they work on a subconscious level. There is no question of that one can ask "Are you orderly?" and count that answer toward the Orderly scale. Internal test statistics reveal to what scale an item belongs, and that scale's correlations with outside criteria reveal what the scale is measuring.

A brief discussion of the scales follows. Statistics can be found on the page with statistical reports, where each scale or factor has its own report.


This is the dimension Introversion/Extraversion. A high score basically means one is happier alone than with others, a low score the opposite. For high achievement in most fields, a relatively high degree of Introversion is needed to be able to do the solitary work required, while additionally high Introversion may contribute to having a wide associative horizon. There are of course exceptions, in particular certain performing arts like singing, dancing, and acting, where Extraversion is a prerequisite.

The biological cause behind this scale is thought to lie in "cortical arousal". Introverts are chronically over-aroused and anxious and therefore tend to stay away from strong stimuli, while Extraverts are chronically under-aroused and bored, and therefore seek outside stimulants.

Introversion/Extraversion is the only dimension of personality that is already observable with some reliability in the first year of life, where it is described as inhibited versus uninhibited behaviour. Other personality features only become apparent after about the age of six.


This is the dimension Stability/Neuroticism. A low score means one has high tolerance for stress and stays calm under pressure. A high score means one gets nervous, anxious and so on even under light stress; one is "neurotic". High Neuroticism makes one vulnerable to affective disorders (depression, bipolar disorder). When it comes to high achievement, some think that neurotics tend toward art, while stable persons tend toward science.

The biological cause behind this scale lies in activation thresholds of the sympathetic nervous system. When activated, this gets one in a fight-or-flight state; prepared for action, while the digestive system comes to a standstill and eating becomes impossible. Neurotics have a low activation threshold, while stable persons have a high threshold.


This is a revised version of the GAIA Asperger questionnaire. A high Aspergoid score disposes for both neurotic and psychotic disorders, as well as for creativity and, rarely, criminal psychopathy. It also appears this scale counts positively toward associative horizon.

The biological background of this scale is not known, but a slightly informed guess is that it is related to both prenatal testosterone (higher testosterone level gives greater risk of Asperger) and the dopamine/serotonin balance (higher ratio gives greater risk). This is speculative however.


This is the range Cold/Empathic. A high score means one has little consideration for the feelings of others, a low score the opposite. A very high score may dispose for crime. It appears this scale also counts positively toward associative horizon, and toward being systematic rather than empathic.


This is the inclination to be cruel, which certainly disposes for crime and psychopathy. This scale appears to be the opposite end of True, or at least has a significant negative correlation with it.


This scale deals with strong sense of justice and desire to punish criminals. High scores on Just also indicate lack of empathy, so that this scale is to some extent an upward extension of Cold.


This ranges from system, order, coherence, and conscientiousness (high scores) to being disorganized and lax (low). This too may be an upward extension of Cold.


This deals with unusual, unshared, not believed (by others) perceptions and experiences.


This is the dimension Truthful/Lying. This scale appears to be the opposite end of Cruel, or at least has a significant negative correlation with it.


This is one's inclination to behave in a way that may displease or endanger others and oneself, and display disregard for law, society and people.


This is one's disinclination to believe in various paranormal, religious, spiritual, and occult matters.


This is one's inclination to give extreme responses on this test; that is, to respond with 0 or 4 rather than with 1, 2, or 3. It simply sums the absolute value of [2 - response] over all of the items.

The three factors

Three factors have been derived from the twelve scales after studying their intercorrelations. Factors are latent variables that underlie the intercorrelations of groups of scales that cluster together.


The Deviance factor score is a standardized sum of the scales Aspergoid, Introverted, Rare, and Extreme.


The Ethics factor score is a standardized sum of the scales True and Cruel (the latter reversed).


The System factor score is a standardized sum of the scales Cold, Just, and Orderly.