• Hand (shape) index: 

The hand index is generally known to vary among males and females: females tend to have slender hands, resulting in that the hand index typically is about 1 point lower in females compared to males (Napier, 1980). But hand index also varies among nations (Asians are generally known to have slender, narrow hands). 

The results for the Dutch University student population show that as expected the males have a 2.6% higher hand index than the females. Interestingly, when the students are grouped for personality a likewise tendency is noticed: extraverts have a 2.9% higher hand index than the introverts: extraverts tend to have wider + shorter hands; introverts tend to have longer + narrower hands.

Males Females Extraverts IntrovertsHand index 43.06 41.94 42.80 41.58

Hand breadth 8.46 cm 7.52 cm 7.83 cm 7.76 cmHand length 19.64 cm 17.94 cm 18.28 cm 18.65 cm

• Palm (shape) index: 

The palm index is generally known to vary among males and females: females tend to have slender palms, resulting in that the palm index typically is about 2.5 points lower in females compared to males (according publications from 7 countries). But hand index also varies among nations (Asians tend to have narrow palms). 

The results for the Dutch University student population show that as expected the males have a 2.2% higher palm index than the females. Interestingly, when the students are grouped for personality a likewise tendency is noticed: extraverts have a 2.7% higher palm index than the introverts: extraverts tend to have short, wide palms; introverts tend to have long, narrow palms.

Males Females Extraverts IntrovertsPalm index 75.87 74.23 75.65 73.62

Palm breadth 8.46 cm 7.52 cm 7.83 cm 7.76 cmPalm length 11.15 cm 10.13 cm 10.35 cm 10.54 cm

• Finger vs. Palm (shape) index (= finger length index): 

The finger vs. palm index provides a measure for finger length. In general females tend to have longer fingers (relative to palm proportions) than males, and in females finger length usually exceeds palm breadth (Japan belongs to the few countries where this tendency can also be observed in males). 

The results for the Dutch University student population show that as expected the females have longer fingers (+2.3%) than the males. Interestingly, when the students are grouped for personality a likewise tendency is noticed: introverts have finger lengths that exceed over 2.0% the finger lengths in extraverts. introverts tend to

have longer fingers; extraverts tend to have shorter fingers.

Males Females Extraverts IntrovertsFinger vs. Palm index 43.35 44.35 43.50 44.40

Finger length 8.49 cm 7.81 cm 7.93 cm 8.11 cmPalm breadth 8.46 cm 7.52 cm 7.83 cm 7.76 cmPalm length 11.15 cm 10.13 cm 10.35 cm 10.54 cm

NOTICE: The picture at the bottom of this page presents a visual impression of these results in an international perspective for finger length variations. 

- How to identify Extraversion/Introversion via hand shape? -

The results presented above show that Extraverts tend to have wider palms with shorter fingers (= a masculine combination), and introverts tend to have longer fingers with narrower palms (= feminine combination). And the so-called 'hand index' appears to be the most significant measure for discriminating both groups in terms of hand shape: e.g. see the picture at the bottom of this article! 

But there are even more perspectives to describe these results. Because in terms of the Elemental hand shapes the results can be summarized as follows (borderline variants not included): 

- the so-called 'Earth hand shape' [E] and it's related variants [E(F)] were not observed to be dominant in any of the

- the so-called 'Fire hand shape' [F] and it's related variants [F(A), F(E), F(W)] are much more common in Extroverts (50.0%) than in Introverts (33.3%);- the so-called 'Air hand shape' [A] and it's related variants [A(F), A(E)] are more common in Extroverts (5.5%) than in Introverts (0.0%);- the so-called 'Water hand shape' [W] and it's related variants [W(F), W(A)] are much less common in Extraverts (13.0%) than in Introverts (47.6%).

These results provide confirming evidence for Gettings' guidelines that 'Fire hand shape' - and in a lesser degree 'Air hand shape' - provides a clue for Extraversion, and 'Water hand shape' provides a clue for Introversion. 

However, the results also suggests that it is very hard to discriminatie Extraverts from Introverts through hand shape only! 

Other results indicate that beyond hand shape more aspects of the hand need to be taken in consideration for finding reliable results) 

More details are described in the articles:6 Hands signs for Extraversion / IntroversionExtraversion, 2D:4D digit ratio & hand shape!

Finger length index: extraverts versus introverts (+ international averages for males and females). De 'dots'show that the finger length variation between introverts and extraverts are larger regarding palm breadth

than palm length - which indicates that in this perspective the 'hand index' is probably the best discriminator! 

http://www.handresearch.com/diagnostics/introverts-longer-fingers-extraverts-wider-palms.htm