Why are elderly people often called “old people” but children are never called “new people”?

Question: Why are elderly people often called "old people" but children are never called "new people"?
- Keywords:
  age,
  old,
  people,
  young
Asked by georgiawheelerxo to Charlotte, Colin, Becki, Rick on 27 Jun 2013.
- Charlotte Dalton answered on 27 Jun 2013:
  
  I guess babies is easier and quicker to say than ‘new people’, but we don’t use ‘oldies’ as that is kind of mean! plus everyone is too busy looking at babies to talk about them 🙂
- Rebecca Scott answered on 27 Jun 2013:
  
  I suppose that comes down to language really and what you see as the opposite to ‘old’. In terms of objects we have ‘old’ and ‘new’ objects. In terms of people we have ‘old’ and ‘young’. Children are often referred to as ‘young people’.
  
  So I guess the answer is because people are living things and not objects.

Question: Why are elderly people often called "old people" but children are never called "new people"?