Seven Deadly Sins: The Biology of Being Human

Humanity’s “less savoury tendencies” drive “our survival and success,” according to this stimulating treatise from neurologist Leschziner (The Nocturnal Brain). Unpacking this theory through the lens of Dante’s seven deadly sins, the author considers how “gluttony” and its “visible signature,” obesity, aided human survival by providing extra energy stores in times of famine; how pride “mak[es] us feel that our achievements are under our own control, hence pushing us to persevere”; and how wrath can serve as a valuable “motivator, a drive to continue striving to reach one’s objective.” According to Leschziner, such personality traits are rooted in a complex constellation of genetic and environmental factors generally outside of one’s control. His argument raises complicated questions about free will that he explores in a thought-provoking discussion of whether traditional binaries of good and evil should be used to evaluate moral decision-making if one’s choices stem from immutable biological drives (though he stops short of embracing a fully deterministic view). Vivid patient anecdotes appear throughout, including the story of a woman with a syndrome that causes uncontrollable hunger, which Leschziner utilizes to illustrate the complex factors that underlie appetite, making weight loss “rarely so simple” as deciding to eat less and move more. Replete with fascinating forays into neurology, morality, and pathology, this is a captivating glimpse at the mysteries of the mind. (Dec.)