Based on Steinberg's study (2008), problems related to health risk behaviors in adolescents are modulated by asynchrony between the substantial development of brain regions linked to límibico system, responsible for emotions, feelings and relationships accompanied by the immaturity of the prefrontal cortex, which controls the actions. The maturity acontecceria this case, when the adult brain is already fully mature, establishing direct links between the systems mentioned.
There is nothing to measure someones maturity. However, we can determine if a person is matured by his gesture, ability to understand the situation of others, behavious and so on.