From the title, I was afraid her writing style might be too cutesy, but it's not at all. It's entertaining and readable, but also substantive.
From Publishers Weekly:
"Borne out of a quest to understand her sister Carolyn's lifelong sinister behavior (which, systems engineer Barbara Oakley suggests, may have been compounded by childhood polio), the author sets out on an exploration of evil, or Machiavellian, individuals. Drawing on the advances in brain imaging that have illuminated the relationship of emotions, genetics and the brain (with accompanying imaging scans), Oakley collects detailed case histories of famed evil geniuses such as Slobodan Milosevic and Mao Zedong, interspersed with a memoir of Carolyn's life. Oakley posits that they all had borderline personality disorder or antisocial personality disorder, a claim she supports with evidence from scientists' genetic and neurological research. All the people she considers, Oakley notes, are charming on the surface but capable of deeply malign behavior (traits similar to those found in some personality disorders), and her analysis attributes these traits to narcissism combined with cognitive and emotional disturbances that lead them to believe they are behaving in a genuinely altruistic way. Disturbing, for sure, but with her own personal story informing her study, Oakley offers an accessible account of a group of psychiatric disorders and those affected by them."