So what exactly is so interesting about this study? Is it supposed to be astonishing that the function of my brain and the function of... the rest of my body are correlated? That if you starve one you starve the other? That if you do exercises to improve the circulation of one, you improve the circulation of the other? That if you get better sleep and avoid stress both of these things will improve?<p>And what does the finding necessarily have to do with genetics, except in the frenzied minds of the genetically obsessed?<p>From the article:<p><i>Hitherto, biologists have tended to disaggregate the idea of fitness into a series of adaptations that are more or less independent of each other. This work adds to the idea of a general fitness factor, f, that is similar in concept to g—and of which g is one manifestation.</i><p>This is the obvious, dressed up as insight and deployed against a pitiful straw man. Biologists have certainly known, as everyone knows, that aspects of fitness are not "more or less independent of each other": My sperm count, my brain function, my ability to win an arm-wrestling competition, and my tendency to resist getting colds are scarcely independent of my diet or my exercise. (Which, indeed, means that they are scarcely independent of my parents' skill at earning money or my society's skill at storing food to sustain itself through droughts.)<p>Better insights, please. Or, perhaps, better journalism.