The book introduces the science and the politics surrounding the nature/nurture debate in psychology via the stories of twin studies. This quick read is approachable for the masses without being inane for those with background. Those who thought that genetics could have some impact on psychological variables (in addition to environmental/social variables) found themselves challenged by the dishonest rhetoric and flat-out fraud perpetrated by those who believed that even to consider such arguments smacks of racism and a thinly-disguised desire for eugenics. Although the growing adoption of psychopharmaceuticals makes biological causes less controversial a decade after this book was written, one can still encounter fallout from the nature versus nurture frenzy. The science behind twin studies is explained well for the general reader, and it is integrated well with narrative details of the research process to keep the interest of non-scientific readers. The reader with some background in psychology will benefit from allusions in the text to key thinkers, but general readers are spared extensive detail. This book does a good job of illustrating how good science can be destroyed by dishonest politics (even by scientists themselves); this topic is no less timely now than when the book was written. Political influences may be discussed among scientists but do not always get the hearing in popular works that is needed to support solid public policies against sociologists with plain-spoken populist appeal. The book contains references for those who would like to further pursue the topics involved, even though it is not really targeted at the type of reader who might follow up with scholarly materials. I would recommend this book to those who are interested in the intersection of science and politics, those who are interested in nature/nurture, those fascinated by twins, and those who want something engaging but-not-too-engaging to read while riding the bus.