'Eric Turkheimer has long been a Socratic figure in the field of behavioral genetics – asking incisive and often uncomfortable questions. He continues this tradition in the present volume which, in particular, challenges the common triumphalist zeitgeist about the degree of progress observed with the 'molecular genetic revolution.' After pondering this volume, which should serve as an antidote to the excessive exuberance of some investigators, readers should have a healthy skepticism, appreciating both the strengths and some important limitations of this challenging field.' Kenneth S. Kendler, M.D., Virginia Commonwealth University