"Ever since the early fascination with my sister's many devious successes, it is the scum who have long held my interest," writes Barbara Oakley in the introduction to Evil Genes: Why Rome Fell, Hitler Rose, Enron Failed, and My Sister Stole My Mother's Boyfriend (Prometheus Books, 353 pages, $28.95)....
Oakley is fascinated with the nature of evil and how evil people can function in society — even succeed at high levels of government, religion, corporations and in ordinary families, like her own. The sister of the subtitle did indeed steal their mother's boyfriend.
The scientist in Oakley investigates how a combination of genetics and environment has shaped evildoers throughout history, including Hitler, Stalin, Idi Amin, Slobodan Milosevic, etc. She comes to the conclusion that they all fall in the spectrum of personality disorders. They're charming on the surface but capable of any number of disturbing behaviors.
So, if you ever find yourself wondering how a person could do some of the things they do, consider that it might be in their genes. And if you're interested in the nuts and bolts of it all, check out this book.