Coming of age is a young person's transition from being a child to being an adult. The specific age at which this transition takes place varies between societies, as does the nature of the change. It can be a simple legal convention or can be part of a ritual or spiritual event, as practiced by many societies. In the past, and in some societies today, such a change is associated with the age of sexual maturity (puberty), especially menarche and spermarche. In others, it is associated with an age of religious responsibility. Particularly in western societies, modern legal conventions which stipulate points in around the end of adolescence and the beginning of early adulthood (most commonly 18, with the range being 16-21) when adolescents are generally no longer considered minors and are granted the full rights and responsibilities of an adult) are the focus of the transition. In either case, many cultures retain ceremonies to confirm the coming of age, and coming-of-age stories are a well established sub-genre in literature, film industry, and other forms of media.