WHY WE SNAP

A neuroscientist asks, “what triggers [our] deadly switch for violence and killing?”

A bizarre encounter with a pickpocket gang in Barcelona was the inspiration for this book, writes Fields (The Other Brain: From Dementia to Schizophrenia, How New Discoveries about the Brain Are Revolutionizing Medicine and Science, 2010, etc.), the chief of the Nervous System and Development and Plasticity Section at the National Institutes of Health. He and his daughter were on their way to attend a neuroscience meeting when a thief grabbed his wallet. The author’s shockingly powerful response was instantaneous. In his mid-50s and weighing only 130 pounds, with “no martial-arts training, no military experience, no background in street fighting,” he subdued the thief with a stranglehold. Looking back on the event, he wondered at the precision of his response. “Somewhere deep in my brain,” he writes, “I must have been taking in this situational information unconsciously.” Fields believes that his response evoked “a deeply embedded automatic life-saving reaction” that had been preprogrammed into his DNA. Throughout the book, he explores how these automatic responses are triggered. He thoroughly examines how threats to survival—to a spouse or child, to self-esteem, to defense of the tribe—can cause the brain to circumvent conscious thought processes and snap into an immediate response. In worst-case scenarios, this can lead to domestic abuse, street violence, and other anti-social behavior. On the other hand, our rapid-response system can save lives—e.g., the author’s response to the pickpocket or a mother who snatches her child from danger. “Acts of heroism happen every day,” writes Fields. “This selfless reflexive response is never referred to as snapping, but from a neuroscience perspective, both heroic behaviors and rage behaviors are driven by exactly the same brain circuits.”

The interplay between conscious and unconscious cognition is not unfamiliar territory, as readers of Daniel Kahneman or Malcolm Gladwell will recognize, but Fields’ personal experience adds a fresh viewpoint to an intriguing subject.