Erikson does note that the time of Identity crisis for persons of genius is frequently prolonged. He further notes that in our industrial society, identity formation tends to be long, because it takes us so long to gain the skills needed for adulthood's tasks in our technological world. So… there is not exact time span in which to find oneself. It does not happen automatically at eighteen or at twenty-one. A "very" approximate rule of thumb for our society would put the end somewhere in one's twenties.