- The simian line: Big Five personality profiling! -


August 4, 2018

NOTICE: For this article a more comprehensive update (based on more data) is available here

Psychological profile for the simian line!

A = Agreeableness | C = Conscientiousness | N = Neuroticism | E = Extraversion | O = Openness

Psychological profile for the simian line with Big Five personality dimensions + it's meta-components.

An in dept study focused on 15 simian line people (without transitional variants) shows that the average comes most close to a schizotypal profile; 60% approaches a profile with average scores on the Big Five meta-components featured with a melancholic temperament.

Simian line variants: single crease vs incomplete variants, transitional variants & normal variants!

NOTICE: Included in the present study are only 15 individuals (= 5,7% from a sample of 262 subjects) who's hands meet the criteria in one or both hands for a 'single crease' or a 'transitional single crease variant' (see picture above). This implicates that 6 other individuals who have been assessed to have a 'normal 4/simian 4' variation of the so-called 'transitional variants' have been excluded from this study (in order to avoid that arbitrary factors become involved whether such 'transitional variants' should be counted to represent a simian variant or a normal variant - especially, since in those variants the 'normal 1' structure is not missing!!!).

What are the implications of the simian line in the perspective of psychology? According medical science the single palmar crease can safely be regarded to represent a 'harmless minor physical anomaly' bearing merely statistical impact towards a wide range of medical issues, diseases and syndromes. The current in dept study shows a likewise statistical impact in the perspective of personality profiling, with results produced by individuals [N=15] which cover a large area of the full spectrum of possibilities in terms the so-called Big Five meta-components Alpha & Beta. However, a deeper analysis of the results does reveal a tendency towards low scores in cognitive efficacy, and a very consistent tendency towards a low score on at least one of the meta-components - only 1 out of 15 simian line individuals does not show this tendency, which illustrates that simian lines are by principle also found in personalities featured with both Cognitive Stability (Alpha) and Cognitive Flexibility (Beta). The average Big Five profile of the studied simian line subjects approaches most closely the schizotypal profile (out of 35 personality profiles), but also not far away from the neutral profile located at the center of meta-component chart presented at the top of this article.

Knowing that the so-called schizotypal personality disorder (not to be confused with the schizotypal profile mentioned above) is widely understood to be a "schizophrenia spectrum" disorder, the result of the present study in the perspective of normal behavior is recognized to show a parallel with earlier reported results in the perspective of abnormal behavior. Because relatively high simian line prevalence has been reported in studies around the words focused on quite a few major psychiatric issues (such as: schizophrenia, psychotic behavior, developmental disorders & occasionally other forms of psychopathology such as Alzheimer disease).

A simian line in both hands vs. left- or right hand only

A small effect-size is also spotted for the variations in which hand(s) the (in)complete simian line is found. Subjects with a simian line in both hands appear inclinded to have scores towards below average Cognitive Stability (= low Alpha); subjects with a simian line in the left hand appear inclined to have scores towards below average Cognitive Flexibility (= low Beta). And subjects with a simian line in the right hand only appear inclined to have scores towards the combination of below average Cognitive Stability and below average Cognitive Flexibility (= low Alpha & Beta).

A summary in terms of the distance from other profiles is presented below for each variation - with 'distance' representing the average square distance derived from the sum of 7 components: the individual Big Five dimensions + Alpha + Beta (using the summarized values for Alpha & Beta).

Simian line in both hands, distance from other Big Five profiles:
narcissistic profile (0,91), neutral profile (1,21), autonomous profile (1,24), antisocial profile (1,74), negativistic profile (1,86).
Simian line in left hand only, distance from other Big Five profiles:
avoidant profile (0,85), depressive profile (0,88), neutral profile (1,21), schizoid profile (1,38), schizotypal profile (1,43).
Simian line in right hand only, distance from other Big Five profiles:
schizotypal profile (0,43), negativistic profile (0,87), autistiform profile (1,15), depressive profile (1,28), avoidant profile (1,70).


Remarkable phenomana in the distribution of simian lines cases among the Big Five profiles!

Various remarkable phenomena have been spotted involving the meta-groups and the individual profiles:

• In the full research population [N=262] more than half of the subjects come most closely to a profile in meta-group 2 (22,1%) & meta-group 12 (28,6%). However, in the simian line sub-group 9 out of 15 cases (= 60,0%) are associated with meta-group 2 and only 6,66% with meta-group 12. It's also remarkable to see that the simian line sub-group has a prevalence close to 3x higher compared to the prevalence of the full research population in the meta-groups 2, 4, 5 & 6

• The hyperkinetic profile shows the highest prevalence among the simian liners, with 3 simian line subjects (= 20%, almost 3x higher than de 6,87% for the full research population).

• Another remarkable results involves the fact that even though only three subjects of the full research population are associated with the depressive profile, two out of these three subjects have a simian line.

• Despite the relatively small amount of simian line subjects [N=15] in the perspective of the 35 Big Five profiles, it is noticable that multiple simian line subjects became associated with the following 3 profiles: the hyperkinetic profile includes 3 simian liners, the depressive profiles includes 2 simian liners, and the avoidant profile also includes 2 simian liners. All three profiles fall under meta-group 2, which typically includes cases with below average scores on all 3 meta-components [CE, CS & CF] and a melancholic temperament.

- What are the implications of this study? -

The impact of the simian line in the perspective of psychology appears similar as seen in the perspective of medical science: even though the simian line may bare value in a group of simian liners, the effect-size is typically just a matter of statistics, which implies that any of the reported tendencies for the full Big Five personality profile does not apply to the full group of simian liners.

Also, the average Big Five profile shown in the picture at the top of this article suggests that the impact of the simian line is most likely most high for aspects of behavior involved with high scores for the Big Five dimension Neuroticism (= low scores for Emotional Stability, the counterbalance factor involved with Neuroticism).

FINAL NOTIFICATION: Even though the palmistry literature has a folkloric tradition in supporting the belief that simian line bare specific value in the perspective of personality or behavior (even though many palmistry authors appear to cherish private percpetions on this matter), the results of this study do not support such beliefs because the variation of behavior among simian line people is very likely much larger than what is suggested by far most palmistry books (this also applies to literature with references to palm reading, hand reading, hand analysis, chirology, chirognomy, chiromancy, chirosophy, etc.).

Distribution of people with strictly assessed simian line (without transitional variants) [N=15] versus controls [N=262] among 13 Big Five personality meta-groups!


Discover the impact size of the simian line relative to other hand signs:
Major hand signs & the General Factor of Personality (a.k.a. 'trait EQ')

A detailed description for each of the 39 Big Five profiles is presented in the article:
System for Big Five personality profile interpretation + 100 celebrity profiles!

Summary of key-constellations in the Big Five personality dimensions:
Neuroticism, Openness, Extraversion, Agreeableness & Conscientiousness:
Hand sign constellations in the Big Five personality dimensions!