The widespread reporting of a man having elective surgical modification of his thumbs to reduce their size in order better to use his touch-sensitive iPhone keypad and the chance remark of a friend that their child uses their thumb to switch on lights led me to wonder about pointing.
…pointing is an activity that sits at the intersection of theoretical accounts of language acquisition, semiotics, social cognition, the neurobiology of communication, the philosophy of mind, and the evolution of language.
All pointing by small people that I’ve seen involves the index finger. Is this in some way innate or is it learned? Would a baby reared by acquired-thumb-dominant people point with its thumb? When/if thumb dominance becomes more widespread would it affect existing digital gestures? would, for instance, the (culturally specific) signal for hitch-hiking of an upraised thumb change to something different because of possible confusion with other gestures? Would you eventually give someone the thumb instead of the finger?
There has, of course, been research conducted into the optimal size of a target for a touch-screen device operated by the thumb with a single hand. Of course. It’s Finnish and involved gathering very specific information:
Hand width and thumb length were recorded for each participant. Thumb length varied between 99 and 125 mm (m=115 mm, σ = 5.75), and hand width varied between 75 and 97 mm (m=88 mm, σ = 6.08).
It seems to me that another important variable, and one which lent credence to the thumb-modding story, is thumb width. That doesn’t seem to have been measured.
Meanwhile I idly picked up a ruler and measured the length of my own thumb. It appears to be mutantly short. Very very much shorter than the shortest Finnish thumb despite my hand width being only just smaller than the narrowest Finnish hand. I wonder whether I am deformed or people in Finland have generally very long thumbs.