At what age range would a child be best acclimated to being a nudist?

Reading this this article, from a few years back, I get the impression that when this family decided to go au natural, some of their kids were well beyond toddler stage and knew they were going from clothes to nothing. Which age range would it have the better or best chance of acclimating a child to the nudist lifestyle with less apprehension and more universal acceptance (from the child’s point of view), and why do you believe that?