It's funny that you posted this because I was just thinking about this myself.
I took my twists out over the weekend and have yet to put them back in, due to time contraints.
This is finals week and between studying for and taking exams, I just have not had the time nor the energy!
Meanwhile, I am addicted to sticking my hands in my head.
I am a 4a/b, and I constantly mess with my teeny tiny coils.
They wrap around themselves, and sometimes I find a little knot at the end of my hair and you know I just gotta try to untangle it.
However, if it does not untangle, I end up snapping it off!
erplexed
But to answer your question, I do not believe that putting your hands in your hair,
in and of itself, is a problem, especially if you're just doing it to cop a feel every now and then
But I do believe that excess rubbing, pulling, snapping off ends, scratching of the scalp, etc. may have damaging effects over time if done consitently.
That's why, for me personally, I must keep my hair put away.
HIH leads me on a hunt for tangles and knots,or sends me to the bathroom to pick out my fro,wich then leads me to destroying my precious coils, which make my efforts on LHCF null and void.....
dk