I was reading 'Bringing Up Bebe' and there's a chapter on why French babies sleep through from about 4months.
Apparently, if a baby wakes up over there, French parents listen to the baby for about 5 minutes and only do something about the crying if it continues longer than that.
The chapter says something like "obviously they don't do this with newborns". Just wondering for anyone that has tried this, when is a baby not a 'newborn' for the purposes of this method?