14:45The Invention of ChildhoodThe Nation's Most Important AssetBBC Radio 4 Extra Duration: 15 minutes Tue 15th May 2012, 14:45 on BBC Radio 4 ExtraMichael Morpurgo presents readings of the words of children about the effect of the wars of the 20th century.GenresFactualHistorySeriesThe Invention of Childhood Source: BBC Online