Brain stimulation points to differences between 'morning people' and 'night owls'

Great, that there's science like this. But I think you can actually train yourself to be either an evening person or a morning person. I once was an evening person, preferred to work late, got up late, and yes, at that time my peak hours were in the night. But then I changed my habits, and now I am a total morning person. I don't think that people are hardwired to be one or the other, but rather that the brain adapts to the behavior we consistently enforce.

Where can I find more details about this Study?