Intro -- Abstract -- Populärvetenskaplig sammanfattning -- Acknowledgements -- List of publications included in this thesis -- List of publications not included in this doctoral thesis -- Contents -- 1 Introduction -- 2 Domestication and the origin of the domestic dog -- 3 Dog-human communication -- 4 Behaviour genetics -- 5 Oxytocin and the oxytocin receptor gene -- 6 Conclusions -- Paper summaries -- References.