Many years ago I watched a standup comic on television explain that the President of the United States has no more control over the country than the bulldog hood ornament on a Mack Truck has in controlling where the truck goes. He was exaggerating but he had a point.
Neuroscientist David Eagleman has a similar argument about the human brain. Our conscious brain (our "I") is the tiny chrome bulldog, while our non-conscious brain is doing the driving. His highly-readable pop science book, Incognito: The Secret Lives of the Brain, offers dozens of persuasive examples to support the idea that our conscious brain is at the tip of our behavioral iceberg.
Here's a few questions Eagleman asks in Incognito:
Why can your foot jump halfway to the brake pedal before you become consciously aware of danger ahead? Why do strippers make more money at certain times of month, even while no one is consciously aware of their fertility level? Is there a true Mel Gibson? What do Odysseus and the subprime mortgage meltdown have in common? How is your brain like a conflicted democracy engaged in civil war? Why are people whose name begins with J more likely to marry other people whose name begins with J? Why is it so difficult to keep a secret? Why did Supreme Court Justice William Douglas deny that he was paralyzed?
Eagleman's answer to all of these questions is that the non-conscious brain is made up of many signal processors, honed by eons of evolution, that compete and cooperate with each other to make decisions that eventually make their way to the tip of the cognitive iceberg, where the "I" takes credit.
I think Eagleman is probably right, but I'm also the kind of person who is easily persuaded by attractively presented arguments and Eagleman, who is an accomplished fiction writer (see Sum: Forty Tales from the Afterlives) is a good story teller, so that has to be figured into my feeling that he's onto something. In any case, this was one of the most entertaining books about the brain that I've read.