Order on individuals in OWL

Hello,
 
OWL 2 primer describes a Family ontology, where one property to describe a
"Person" is DataProperty "hasAge" ranging in integers.
How to define a relationships "elder"/"younger" on individuals of Persons,
such that setting hasAge values to all persons in a family I can deduce the
seniority order in this family.
 
Looking broader, the question might be like: how to define orders on
individuals basing on their particular data property values?
 
Natalya Keberle
ZNU, Ukraine