When did it become mainstream for parents to go down the Cry It Out route?Why do all the parenting 'experts' insist on telling mothers and fathers to ignore their instincts and focus on self-settling instead?And why do so many of us feel like failures if our babies don't yet sleep through the night?To find out how we got here, I spoke to anthropologist Alice-Amber Keegan from the The Durham Infancy & Sleep Centre about the history of baby sleep and night-time parenting.For more information about biologically normal infant sleep please see www.basisonline.org.uk