This book provides an overview of the recent history and methodology of behavioral genetics and psychiatric genetics. The perspective is primarily philosophical and addresses a wide range of issues, including genetic reductionism and determinism, "free will," and quantitative and molecular genetics. The latter covers newer genome-wide association studies (GWAS) that have produced a "paradigm shift" in the subject and generated the problem of "missing heritability." Cases involving genetic testing for IQ and for attention deficit hyperactivity disorder (ADHD) are presented. This text examines t ... More

This book provides an overview of the recent history and methodology of behavioral genetics and psychiatric genetics. The perspective is primarily philosophical and addresses a wide range of issues, including genetic reductionism and determinism, "free will," and quantitative and molecular genetics. The latter covers newer genome-wide association studies (GWAS) that have produced a "paradigm shift" in the subject and generated the problem of "missing heritability." Cases involving genetic testing for IQ and for attention deficit hyperactivity disorder (ADHD) are presented. This text examines the nature-nurture controversy and developmental systems theory using C. elegans or "worm" studies as a test case, concluding that genes are special and provide powerful tools, including "deep homology," for investigating behavior. A novel account of biological knowledge emphasizing the importance of models, mechanisms, pathways, and networks is offered that clarifies how partial reductions provide explanations of traits and disorders. The book examines personality genetics and schizophrenia and its etiology, including quotes from a number of prominent researchers interviewed in recent years. Caspi and Moffitt's research and critiques of their "candidate gene" approach are discussed. It is noted that thousands of genes are likely to influence human personality. The book concludes with additional philosophical implications of the genetic analyses raised in the earlier text, some major worries about "free will," and arguments pro and con about why genes and DNA are so special. A pessimistic view of the current state of the field, but optimism for the future of the subject, is proposed.