I love myth busters! Progression requires an open-mindedness. It is so sad that someone labeled you as "right-brained" and set you up for failure in Algebra. Even *if* something is harder for one than another, I like the words of Ralph Waldo Emerson as it applies here: “That which we persist in doing becomes easier to do, not that the nature of the thing has changed but that our power to do has increased.” In my experience, those who struggle and overcome make the best mentors, because they know what it is like to struggle.
Do you have any meta-analysis research studies that you suggest? I love research, and your article peaks my interest on this subject. Also, could you include the references to the 1960s studies? This topic is quite intriguing. I studied dozens of articles on cognitive load for my graduate research. It seems that neuroscience is in its infancy, but I love a good meta-analysis if I can find one.