@pjacock @simontatham I can't think of an example, but I would expect the purpose of one's typing would probably also play a role in the types of error one produces.
I never really learned to touch-type, and though I can type without looking at the keyboard, I think the pattern of my hand movements is not the same as a trained typist would use.
A significant reason for that is that most of my keyboard work has been programming, which is heavily weighted towards single words and symbols, rather than sentences, and short bursts of editing rather than just typing out contiguous 'tracts'.

@GerardThornley @pjacock yes, I've always thought formal touch-typing training is better suited to people typing English text than to programming.

I was never formally trained at all. I just typed, mostly on my own time, since an early age, and my motor cortex gradually optimised my actions without me really paying attention, until I could hit >100wpm on a good day. But it's noticeable that the style I evolved is not the usual touch-typing style with a fixed posture on the home keys. It's far more flexible – I can adapt to having a few fingers out of action (e.g. holding a pen or a snack) almost without having to think about it, just using whatever fingers I have for whatever they need to do. And I never use Caps Lock, because I find it easier to hold down Shift with one finger and just use the other 9 however seems sensible. And often I find my left hand covers _more_ than half of the letter keys, while my right hand is free to go for punctuation symbols and the arrow keys (or all the way over to the mouse or trackball), since – as you say – programming is much more heavily weighted towards both weird characters and editing your existing code.

Another noticeable thing about my posture is that my wrists don't bend outwards in the way they'd have to to settle my fingers on the home keys. My hands land on the keyboard at an angle, and just deal with it. Perhaps this is good for getting less RSI!

@GandalfDG @GerardThornley @pjacock me too, although in my case that could easily be early influence from the ZX Spectrum, on which the two shift keys were semantically different!