Why do different cultures have different coming of ages? For some the advent of adulthood is celebrated by lavish parties, for others, by endurance tests and initiation ceremonies. But they all share a commonality - the symbolic passing of childhood into the adult world which usually confers new rights: legal, political or religious.

But what really changes? And why is adolescence, for many, lasting longer than ever?

(Image: Mexican teenagers pose for photos following quinceanera, a coming of age party. Credit: John Moore/Getty Images)