The puns will start to sour, I'm sure. But this article from William Saletan at Slate.com reports on a Northwestern University study that suggests ADHD might be a genetic adaptation suited to pre-agricultural settlement patterns and lifestyles.
I recently watched 10,000 BC, a stupid and wildly improbable historical nonsense. Yet I found myself, as I have at natural history museums, fascinated by pre-Bronze Age technological societies, and the primitiveness we associate with their minds solely because of their tools. While these tribes surely had some divisions of labor based on physical attributes and cerebral skills, it is reasonable to suppose that nomadic tribal life required more broad skill development of an individual than does our increasingly technologically specialized arrangement.
I wonder if this means there is a correlation to the ADD's interest in everything, and desire to master many skills, and why that seems increasingly disfavored in our niche-driven economy.