'Top-notch'Good Housekeeping - BEST PARENTING BOOKS'Helen has a way to take big ideas and convey them with warmth and wisdom' Dr Rangan Chatterjee'A well researched study injected with humour and humanity' Mail on Sunday*Featured on The Happiness Lab with Dr Laurie Santos*After a decade of living in Denmark and raising a family there, Helen Russell noticed that Nordic children are different.