Since it's been a little while since I wrote something I pulled completely out of a dark orifice:
Circadian Rhythms, as many of you know, are cycles of biochemical and physiological processes in biological organisms. In humans, these are a key influencer in how we sleep and how and when our organs function. There are endogenous and exogenous factors that effect these rhythms, as anyone who recently returned from China can attest at 3am.
It turns out that your body is not all on the same timezone. There are organs that do what they want, when they want, regardless of stimuli ('peripheral oscillators'). There are factors (called 'zeitgeibers') that influence other parts of your anatomy, like how sunlight on your skin alters melatonin production. Your body is not, as we say in my business, time-sync'd.
But what if these endogenous factors are as susceptible to human evolution as other aspects of our growth? Just as hair/eye color are immediately identifiable factors that you can genetically track, what if there are natural, innate, circadian rhythms and peripheral oscillators that you inherit through your genes as well? What if your natural predisposition is being able to digest the foods indigenous to where certain of your ancestors were from? What if your peak-learning-times were those shared by your European or Asian ancestors (and time sync'd to Europe or Asia instead of the Americas)?
For example, what if you are living in the United States, eating the high-fructose-corn-syrup-saturated diet so common here, while your body is genetically predisposed to eat a rustic, French country meal during Central European dining times? What if you are perpetually walking around the states in non-peak mental-acuity, unless you venture to Europe on holiday, and suddenly find yourself on mental-overdrive?
I'm going to read all the chronobiological primers I can find and see if there is any research to affirm/disprove my premise above. I ALWAYS feel like I am on some cognitive-hyperdrive while on Euro-travel, and definitely function better anywhere when I eat the cuisine of my Continental forebears. I hope there's a reason other than that the United States just makes me slower.