answer:
because it creates an order
explanation:
some researchers suggest the use of chronological age as a marker for the timing of adulthood, whereas others suggest the transition to adulthood is better characterized by events or rites of passage such as graduation from school, starting a job, or having a family (neugarten and hagestead 1976).
now, unfortunately, i don't know what author you are talking about, but i hope this helps.
good luck :)
have a nice day !!
