<p>Sometimes it is obvious to everyone when an idea is harmful, or a piece of advice is damaging. But not always. Occasionally bad ideas and terrible advice end up being accepted in society and supported by people in authority.</p><p>In such circumstances, one of the most powerful tools for changing people's minds is evidence – scientific studies that show beyond doubt that the bad idea is, indeed, a bad idea.</p><p>That's the subject of a new book by Helen Pearson, titled Beyond Belief: How Evidence Shows What Really Works.</p><p>An editor at the scientific journal Nature in her day job, the book chronicles those determined individuals who shake up the status quo by gathering just the right kind of evidence.</p><p>One story in that book stood out to us on More or Less as it shows just what happens when you don't have the evidence you need to challenge a dangerous way of doing things.</p><p>It's the story of a piece of advice from childcare expert Dr Benjamin Spock.</p><p>In a 1958 revision of his bestselling parenting guide Baby and Childcare he made a small change to his advice on sleeping position – advising parents to put their babies to sleep on their front.</p><p>It eventually became clear that this sleeping position was associated with a significant increase in the risk of sudden infant death, or cot death.</p><p>CREDITS:</p><p>Presenter: Charlotte McDonald Series producer: Tom Colls Production co-ordinator: Brenda Brown Sound mix: Rod Farquhar Editor: Richard Vadon</p>