The phylogeny of the nervous system has been very well understood by evolutionary neuroscience. Since the first self-defense reactions (irritability) of the unicelular organisms, going through the procceses of centralization, cephalization, and tele-encephalization, the goal of the system is to survive by catching the changes of energy of the enviroment (stimulus) and give and adequate suvirval response to it.
The evolutive instruction of the nervous system is to survive and the diversity of responses increases with the incorporation of new structures.
The last portion in the evolutive order of appearance of the central nervous system, is the prefrontal cortex, the one who give the organism who possess it the capability of self-knowing, the predictibility to future and the abstract thinking. We are not the only one species with prefrontal cortex that have ever existed and we are not the only one from the currently living species.
The prefrontal cortex at born is just starting to shape; many structures inside the brain have the enough madurity in the newborn, in particular the vegetative systems, but not the recent structures. It means that during childhood and adolescence the prefrontal cortex is still in developing. Just as the way the human infant has a particular age to starting to walk (because the system has reached the madurity enough to allow it), the prefrontal cortex has its own speed of growth.
It ends its developing at an average of 25 years of age; so, it is the last part of the nervous system to ends madurity, and the reason of it is that the prefrontal cortex has been the last in appearance in the phylogeny of the nervous system.
The price that we pay as human species to born with brains with big capacity, but "incomplete", is called childhood. During this period of time the human infant is unable to survive by it self; all of us need parental care during childhood.
Because this inmaturity of the prefrontal cortex, the human infants are unable to recognize the consequences that their own acts will have in the future; they operated without thinking of the consequences of their proceed.
The adults of many species -including us-, teach their infants according to a conductive arrangement; the adults allow or avoid some particular behaviour, acording the culture, the social structure and the environment where they live. But during this educational process, because there is a lack of maturity of the prefrontal cortex, the infant has not idea why some manners of acting are awarded while others are avoided.
This is the way a culture is maintained alive, by teaching the children of the social group what the group of adults think is right and what they think is wrong.
When the prefrontal cortex has completely developed, the new generation will add its own experience and the individual ability to process the environmental information; because it is hardwired in their genes, will do the same with their offspring.
So do not treat children and adolescents very hard ; they do not have the enough neural structures to understand what you are trying to reach with your educational process. Just think clearly what do you believe they have to learn and make sure that they be able to survive this phase of life.
The Prefrontal Cortex Evolution and the Educational Process In Human Childhood