I find the premise and what I could gather from the description of the experiment interesting, but not conclusive of anything.
I do think that "self control" is complicated (and could site a lot of research from undergrad and grad psych classes). There was also an experiment in which children were give candy and told not to eat it before they were given permission. Some of the kids had the candy sitting in front of them, some were given techniques to help them wait. The chidren that had the best control were those that were given something to do.
It's a lot easier to have self-control, if you make it easier not to rely on only self-control. It's easier to avoid eating an entire gallon of ice cream, if you buy none or buy one of those 4 oz cups individually rather than stock the freezer with six different varieties.
Willpower is part of the solution, but it's not the only part.


