ming of the onset is by inherited factors within the chromosomes of the individual. The anatomy of chromosomes is well known, however the physiology is limited to describing how genes on the chromosomes code for the proteins that are the makeup of hormones. It is not understood what causes a certain gene to be expressed. Until these factors can be shown the theory of genetic control over the onset of puberty cannot be proven as fact. Some patterns have been shown within a group of individuals that are exposed to similar environmental conditions such as nutrition and health, and enter puberty at differing times, that points to a correlation between social interaction and the timing of onset. For example family environment. A stress created by family or other factors can slow the onset of maturation. However, this correlation can be explained by experiments that have proven that stress can affect the secretion levels of hormones. This further proves that the factors controlling the onset of puberty are biological. Another argument to biological control over the onset of maturation is history. Throughout history the timing of puberty has remained similar given similar environmental conditions. Adolescence ends when adulthood begins. All societies define what is considered an adult. Some define it different than others but the characteristics are largely of social nature not of biological facts. Some societies have discontinuous transitions from adolescence to adulthood, meaning the change in status is sudden and marked. For example ceremonies to mark the entrance of an individual to adulthood. But the timing of the transition is still decided on by society. Other societies have a continuous transition from adolescence to adulthood which is largely defined by social status. Some events that mark transition are graduation from schooling, entrance into work-force, marriage and parenthood. The timing of these events has chan...
