I purchased this book as a required text for a graduate class on human behavior and crime. I admit I was very skeptical about the effects of biology on criminal behavior, but after reading this book, I am beginning to change my views. In contrast to older biological theories, this text uses the risk factor approach to crime causation, which looks at biological factors and environmental influences to explain behavior. It fills in many of the blanks left by other theories. If you are an open-minded person looking to enrich your understanding of criminal behavior, I highly recommend this book.