Speakers often ask for numbers and statistic in speeches to support their message, but is quantifiable data the best idea in a speech? In a speech, ie not to be read with the eyes, on a screen or on paper, with the possibility to pause, analyze, and reflect, but heard by the ear, in a flow of words and sentences, with hardly any time or tool to put them into perspective. If you wonder on what grounds numbers and statistics delivered to an audience land, Hans Rosling’s book is an eye-opener. Professor and TED-speaker Rosling explains why most audiences, even advanced or expert audiences, often perform extremely poorly when asked on their worldview (worse than random, worse than chimpanzees, as he shows). And if the worldview is wrong, so is the thinking. Rosling’s expertise is international health but the relevance of this book goes far beyond, as he presents and explains ten instincts that distort dramatically our understanding of the world. This book provides speechwriters with understanding of the ten instincts that alter our thinking, arguments to introduce only with great care numbers and statistics in a speech, and advice on how to put factfulness in practice for politicians, media and citizens.