Finger length re-defined: the 'finger length index'!

**Martijn (admin)** on Mon May 26, 2014 11:42 pm

For more than a century finger length (proportion) has been known to represent a manifestation of genetics & hormones combined. Unfortunately, the assessment of finger length (proportion) has not been defined very well. So far nearly all sources have defined finger length proportion relative to a single aspect of the palm: some sources use palm length, other sources use palm breadth (= hand width measured at the metacarpals). But interestingly, the argument for using only palm length or palm breadth is missing: it appears that choices in the past were made on just arbitrary preferences.

Therefore I present a propose for a new, more detailed approach to re-define finger length proportion: the 'finger length index', which is defined as the average proportion of finger length relative to palm length & palm breadth:

Finger length index = FL/((PL+PB)2)

finger length relative to the average of (both) palm length and palm width together!

The picture below (click HERE for a larger version) describes how the 'combined' approach produces different results compared to the approach based on palm breadth (= FL/PB) and palm length (= FL/PL); the picture e.g. describes how finger length varies between various international populations, the sexes, and the major primate families + species.

NOTICE: The horizontal axis represents the ratio of palm breadth versus palm length (= PB/PL); the horizontal & vertical axes together represent a measure for... hand shape!

A more lengthy article about how finger length correlates with evolution, genetics & hormones is available here:
http://www.handresearch.com/diagnostics/finger-length-re-defined-evolution-genetics-hormones.htm

**Martijn (admin)** on Tue Jun 10, 2014 7:24 pm

... And here's a brand new article defining 'extraordinary finger length' (extraordinary long fingers) very precisely:

http://www.handresearch.com/diagnostics/extraordinary-long-fingers-dolichodactyly-finger-length-minor-physical-anomaly.htm

The picture below presents (new) guidelines that can be applied to the full world-population; the picture also includes details which suggests that hand shape & finger length do not vary much across regions around the world (see the 3 large international groups included):

Finger length re-defined: the 'finger length index'!

Finger length re-defined: the 'finger length index'!

Re: Finger length re-defined: the 'finger length index'!