I'd like to know if there has been an study, or different studies for each activity with which the ranking could be done, that determines a ranking like that with mind intensive activities, I refer to things like playing chess, performing advanced maths, programming, writing a book with care of all its details, performing IQ tests and whatever activity that would produce "brain fatigue" in a typical person within some hours.
I guess the more brain activity it supposes the more tiring the activity would be, although not sure about that. It would also be a good point to determine how hard some activities are.