My first thanks need to go to my agent, Sally Holloway of Felicity Bryan Associates, who managed to see some promise in a very dry academic manuscript, beat some popular-science writing sense into me and has been there for help and advice throughout the completion of this book. Secondly, I would like to thank my editor, Claudia Connal at Simon & Schuster, for all her gentle guidance and excellent editing. She has been incredibly good at spotting academic waffle and keeping me on track. My unending thanks go to my boss at Oxford, Professor Robin Dunbar, for being an inspirational scientist and author, supporting me throughout my academic career and allowing me to spend some time looking at dads when, really, I should have been doing something else. I also need to thank the members of my research group, the Social and Evolutionary Neuroscience Research Group within the Department of Experimental Psychology, for their helpful discussions. In particular, my thanks go to Dr Ellie Pearce, who read and commented on early chapters of this book. I need to thank the National Childbirth Trust, and, in particular, Fran Hill and Jenny Barrett, who helped me to recruit dads and gave their input on survey design for my studies. I need to thank my funding body, the British Academy, for financing my first study and setting me on the road to fatherhood research. I need to thank my friends for always asking how it was going and offering tea and cake when the going got tough. In particular, my best friend F fiona, who ‘entertained’ herself on her many transatlantic flights with drafts of early chapters. To my work colleagues Moose, Bear and Sam: what they lack in conversation they make up for in slobber and hugs. And to all my family. But, in particular, to my mum and dad, who brought me up to believe that learning was a joy, who supported me emotionally and often financially through my degrees and who, by being amazing grandparents, enabled me to return to work and pursue my research. They have also been willing guinea-pig readers for many theses and book drafts – hopefully this was a bit easier to read than the PhD. To my beautiful stepdaughter, Lydia, and my gorgeous daughters, Hebe and Kitty. They are the point of my world. And to my husband, Julian. He was the inspiration for this book and has always been my greatest love and support. Thank you.