The fingers of the human palm exhibit a (bi)symmetrical pattern with regards to their size, in the sense that the thumb and the pinky are almost the same size, and the same holds for the index and ring finger. I was wondering what the biological imperatives and/or evolutionary advantages behind this physical characteristic are.

The only rationale I personally am able to come up with is that this particular arrangement might be optimal or ideal for grasping, handling, and manipulating objects, but am unsure of its truthfulness, and, even if correct, I would still be interested in exploring other possible avenues.

  • 5
    $\begingroup$ Possible duplicate of What is the evolutionary cause for various finger lengths? $\endgroup$
    – tyersome
    Commented Nov 17, 2019 at 20:23
  • $\begingroup$ The thumb is NOT the same size as the pinky. You are perhaps looking only at the first two bones of the thumb. Look at all three bones, and you will find that it is longer: probably longer than any of the other digits. (At least it is on my hands.) $\endgroup$
    – jamesqf
    Commented Nov 18, 2019 at 3:37
  • 1
    $\begingroup$ @jamesqf: All fingers, not just the thumb, extend into the palm of the hand. $\endgroup$
    – Lucian
    Commented Nov 18, 2019 at 4:38


You must log in to answer this question.

Browse other questions tagged .