In tribal societies entry into an age grade – generally gender-separated – is often marked by an initiation rite, which may be the crowning of a long and complex preparation, sometimes in retreat.
In most cultures, age grade systems, as with age sets, are the preserve of men, and it is the older men who control a society's secret knowledge, collectively or restricted to a council of elders and/or specific positions such as shaman entrusted with the preparation of initiants.
Closely related age-grade systems are common among East African Cushitic communities.
[Another example is that of the Maasai] Gadaa through history came to organize social life around the series of five generation grades which assign obligations as well as rights to members of the society.
For example, the system operated as an educational institution by providing periods of training and skill development in each grade and by casting all those YUBA (who had finished the full cycle consisting of five-grades) in the role of teachers and advisors.