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.

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.

That's the subject of a new book by Helen Pearson, titled Beyond Belief: How Evidence Shows What Really Works.

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.

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.

It's the story of a piece of advice from childcare expert Dr Benjamin Spock.

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.

It eventually became clear that this sleeping position was associated with a significant increase in the risk of sudden infant death, or cot death.

CREDITS:

Presenter: Charlotte McDonald