Weird. When I tried to just "type random" without looking at the keys, it was routinely getting me around 75%. I tried looking at the keys as you described, and my score immediately dropped to around %50 and was even below %50 for a bit. Then it crept back up to around %60 when I started talking to a co-worker while typing.
There's been a number studies that showed that humans are bad at random number generation.
e.g. "Humans cannot consciously generate random numbers sequences" http://www.ncbi.nlm.nih.gov/pubmed/17888582
I guess that goes back to the original premise of the experiment. That "free will" is unpredictable. And the way I thought about it is that for me to have a true inclination -- not to just do it "randomly" -- I'd have to look at the keys and feel something.
