ACKNOWLEDGMENTS

I have been fortunate in getting to know many of the leading researchers in the study of the brain and emotions, and they have been generous with their time and insights. For this I thank Nancy Adler, Ralph Adolphs, Patricia Churchland, Antonio Damasio, Richard Davidson, Raymond Dolan, Paul Ekman, Chris Frith, Fritz Henn, Steven Hyman, Tom Insel, Ravi Kapur, Charles O’Brien, Detlev Ploog, Jaak Panksepp, Signe Preuschoft, V. S. Ramachandran, Carol Ryff, Wolfram Schultz, Terrence Sejnowski, Alexander Shulgin, Frans de Waal, and Walter Zieglgänsberger.

I owe a special debt to those scientists who not only answered my questions but also read parts or all of the manuscript: Udo Becker and Isabella Heuser of the Free University of Berlin’s Psychiatrisches Klinikum Benjamin Franklin, Volker Gerhardt of the Philosophische Fakultät of Berlin’s Humboldt University, Rainer Landgard of the Max-Planck-Institut für Psychiatrie in Munich, Norbert Schwarz of the University of Michigan in Ann Arbor, and Rainer Spanagel of the Zentralinstitut für Seelische Gesundheit in Mannheim. Their friendly criticisms were enormously helpful in bringing me closer to my goal of writing not only as clearly but as precisely as possible. Responsibility for any errors are, of course, mine alone.

My assistants Jana Binder, Christoph Leischwitz and Martina Kienow have gathered and gone through a huge amount of material. Without them I would not have been able to manage the preliminary work of this project in such a relatively short time. Monika Klein not only browsed the Internet and spent hours in the library but copyedited the manuscript and helped me prepare the notes and bibliography.

My friends Joerg Altekruse, Ulrich Bahnsen, Stefan Bauer, Hildegard Diehl-Bode, Volker Foertsch, Margitta Holler, and Wolfgang Schneider repeatedly took the time to review the concept and the manuscript in its various versions from the reader’s perspective. Their praise and blame were most stimulating and helpful, and thanks to them I was spared the loneliness that is endemic to writers.

When questions arose, Uwe Naumann of the Rowohlt Verlag was always open to my wishes and advice. Ursula Nussbaum managed the publicity and worked on the book’s behalf with care and engagement. Eva Ninnemann and Elektra Rigos designed the successful website (www.stefanklein.info). And Matthias Landwehr, my agent, was enthusiastic about this project from the beginning and then skillful in representing it.

My wife, Alexandra Rigos, accompanied this book in all phases of its development, from vague idea to completed page proofs. It owes an infinite debt to her keen judgment, sensitivity, and feeling for language. To whom else should I dedicate a book on happiness?

—Stefan Klein, PhD

My thanks to Elizabeth Lewis and Carol Sabersky for their patient and invaluable help with the translation.

—Stephen Lehmann,

Philadelphia, December 2005