Incognito: The Secret Lives of the Brain by David Eagleman

Who's at the wheel? What really controls the decisions and actions we commonly think of as ours? Do our brains really belong to us, or do we belong to our brains? David Eagleman kicks up a hornet's nest of head-scratchers like these throughout this fascinating book that reveals how much our unconscious minds control our lives.

Surveying a slew of neurological research, Eagleman shows how the human brain has evolved to handle the large majority of daily life through sub-conscious routines, or--as he puts it--zombie programs. This goes well beyond low-level survival activities like breathing and digesting food. Almost any skill that we master becomes an embedded zombie program that operates better without conscious attention. Riding a bike, catching a pop-fly, or playing the piano all depend on a myriad of complex calculations that our brains carry out without active through. What's more is that most of the decisions we make, such as which member of the opposite sex to pursue or whether or not to behave violently, are based not on rational thought--but rather brain chemistry to which we have no conscious access.

After convincingly laying out this argument, Eagleman raises some compelling points about how the criminal-justice system should adapt to reflect our new understanding of behavior and the brain. If we don't actively choose our genes and if those genes (coupled with experiences) don't just influence violent, anti-social acts but rather direct them, he argues, then the question of culpability has no place in a murder trial. Rather, the standard should be whether or not an individual poses a future threat to society. Then instead of punishment and retribution, he says, justice should focus on rehabilitation through advanced therapy influenced by the latest neurological breakthroughs.

Though he definitely has a point, Eagleman ignores one important role of the justice system--to depersonalize crimes and convert the motivation for revenge into the understanding that criminals must "pay a debt to society." Even if we can someday "cure" a serial killer through brain rehabilitation, there will no doubt be some need to to satisfy the victims families' desire for punishment, or else their unconscious zombie routines are likely to push them toward violent retribution.

Eagleman's point isn't to obliterate the idea of personal responsibility, but the argument does raise some troubling questions about individual agency and even identity itself. We're all fond of believing that we are who we are and we do what we do because of the decisions we make. Yet Eagleman shows that even in studies measuring why people chose to raise a finger at a certain moment, it's clear that the unconscious mind initiated the action before the conscious mind decided to take credit for it. Even though his final chapters show that the complex interaction between nature and nurture invalidates a reductionist understanding of people as no more than the sum of their neurons, it's impossible to leave this book without wondering what we really mean when we say "I." Am I the me that takes credit for all the things my zombie programs really do, am I simply the sum of all these zombie programs, or am I the unknowable something in between?