The myth of ability or practice practice practice

I was impressed by Professor Stobart's debunking of ability. I loved the analogy made with language acquisition: clearly there is a genetic predisposition to learn but the environment plays a crucial role, which is why my Mandarin is worse than that of many five year old kids.

And I too had been impressed by Malcolm Gladwell's book Outliers which suggest that 10,000 hours of practice is what is needed to make you an expert. 

But I thought that idea had been exploded by the research of Professor Macnamara and her team who did a meta study of 88 papers and concluded that practice only explained a small percentage of success in various fields: 26% in games, 21% for music, 18% for sport, and just 4% for education.
http://www.sciencedaily.com/releases/2014/07/140728094258.htm

Is this because practice is only really important in activities that are largely physical or is it because we just don't know how to teach in education and if we did practice would account for a larger percentage.

Perhaps the myth of ability is the reason for this tiny 4%.

The other thing that occurred to me is that Prof Stobart's ideas might chime with those of Carol Dweck. Dweck suggests that learners learn better/ faster if they have a 'growth' mindset, ie they believe that if they work harder they will become more able, rather than believing that their ability is fixed no matter what they do. Perhaps it isn't the practice that is important, perhaps it is having the right self-beliefs.

Finally, I wonder if the type of practice is important. Stobart said it had to be 'deliberate' practice, ie practice that focuses on the weaknesses rather than just doing more and more of the same thing. This is why you might need a coach (or a tutor). But I also want to apply my rip, mix and burn model of learning to it. Isaac Newton and Robert Hooke bandied ideas about gravitational fields in the coffee houses and discussion groups they both attended. Hooke probably suggested the inverse square relationship to Newton in one of their meetings. But after this collaborative learning, Newton went away and buried himself in Maths for two years and came up with his theory of gravity. Hooke's mind flitted from topic to topic like a butterfly. So becoming an expert learner may have something to do with focus.

But the expert learner I used on the discussion forum, whom I called J, was a bit of a Jack of All Trades: he was pool champion for the region, played cricket for the Town and worked in his parents' shop as well as doing A-levels with me. How could he excel in everything if he needed to put in 10,000 hours of deliberate practice. And he's not the only one I've known.