According to Candy (2011), “Under most laws, young people are recognized as adults at age 18. But emerging science about brain development suggests that most people don’t reach full maturity until the age 25.” Is it time to revisit the legal age of adults? It is time to ensure that constitutional protections in the United States align with the science of brain development, making important distinctions between the nature of the adult brain and the juvenile brain. This article will demonstrate why the legal age of adulthood in America is too young and should be adjusted upward.
Adults are those who have reached the age of majority, which can be defined as the “legally defined age in which someone is regarded as an adult, with all the attendant rights and responsibilities of adulthood” (US Legal, n.d.). Is it legally correct then, that as people only have full brain maturity at around age twenty-five, they are given these responsibilities and rights from the government and state? State laws define what the age of majority should be. Given that, it is different according to the particular state, although most states put the age at age 18. Once the age of majority is attained, adolescents become adults in the eyes of the law, and as such, are entitled to various rights, such as consenting to marriage and the right to vote. In addition to those rights, adults are subject to some restrictions, including being treated like adults under the law. The Constitution’s 26th amendment protects the right of 18-year olds to vote, with some state laws also protecting that right. There is some civil responsibility with adulthood, too, including negligence liability and the ability to legally enter into contractual obligations. Moreover, parents’ responsibility to look after their children is terminated when the child attains the age of majority. If the adolescents’ brains are not fully matured at age 18, then these teenagers that still need the help and support of their parents may suffer as a result, and possibly turn to smoking, alcohol, and illegal drugs, which can have a particularly harmful effect on young people.
In addition to the various rights already discussed, the age of majority is also applicable to other issues including; marriage, licensing, emancipation, the purchase of alcohol, foster care, the ability to instigate law suits, determining the head of the household, and guardianship (US Legal, n.d.). This substantial list highlights a very serious problem, in that scientific and biological research has determined that at the age of majority, that is to say at the legal age of 18, adolescents have not reached cognitive maturity, and to that end the law governing the age of maturity needs to be amended to increase the age to twenty-five years old.
Brain scientists differ a bit on their explanation of when the brain is fully formed and functional. Previously, many experts thought the brain was probably fully mature in mid to late teen adolescents, yet that theory was quashed when research strongly indicated that the maturation process could go on until at least 20 years of age. Nowadays however, even though the development of the brain is affected by considerable individual variation, the majority of neuroscientists are in agreement that the development of the brain is likely to carry on “at least the mid-20s – possibly until the 30s” (Mental Health Daily, 2015). Scientists indicate that the portion of the brain that controls decision-making—the pre-frontal cortex—is not fully formed until well into the 20s for men and slightly before that for women. This means that young people are more compulsive, less likely to consider the long-term implications of their decisions, and more prone to risk-taking behavior. These findings have major implications for lawmakers trying to put together suitable policy in relation to the standing of legal “adults.”
Research studies using longitudinal neuroimaging have shown that the brain of an adolescent carries on maturing substantially into the 20s. As a consequence of this finding, there has been a great deal of interest in regard to connecting maturity of judgment and neuromaturation. While more empirical evidence connecting real-world adolescent behavior and neurodevelopmental processes is needed, “Public policy is struggling to keep up with burgeoning interest in cognitive neuroscience and neuroimaging… Adolescent brain development research is [however,] already shaping public policy debates about when individuals should be considered mature for policy purposes” (Johnson et al, 2009). Public policy often lags behind the scientific community in its understanding of the brain. At current, policy reflects an arbitrary line drawn because some distinction must be made between adults and children. That arbitrary line was drawn, however, using information that has since been disproven.
Older science failed to take into account the important of the frontal lobes. The area of the frontal lobes which is found just behind the forehead, is the pre-frontal cortex. This region of the brain gives a person the means to apply good judgment when they are faced with hard situations. Over the last few years, researchers have analyzed the different facets of adolescents’ prefrontal cortexes which are connected to the maturation procedure (Arain, 2013). This area works to moderate peoples’ right behavior in social situations, abstract thoughts and cognitive analysis. It obtains data from all the body’s senses and masterminds actions and thoughts for the purpose of attaining specific goals. The reason for a percentage of adolescents displaying behavioral immaturity is down to the fact that this particular region of the brain is one of the final areas to reach maturity. Throughout adolescence, a few prefrontal cortex executive functions remain under development. Casey et al (2008) wrote, “The fact that brain development is not complete until near the age of 25 years refers specifically to the development of the prefrontal cortex.”
The maturation of the brain which occurs between age eighteen and twenty-five is basically a continuance of the procedure which started at the time of puberty. To put this into context: at the time adolescents are eighteen years old, they are approximately midway through the prefrontal cortex’s complete development stage. At eighteen years old, this area of the brain does not possess anywhere near the functional capacity that it possesses later on at the age of twenty-five. With this in mind, young people can at times experience “major struggles with impulsive decisions and planning behavior to reach a goal. The brain’s reward system tends to reach a high level of activation during puberty, then gradually drifts back to normal activation… [at around] age… 25” (Mental Health Daily, 2015).
Some critics point out that in public policy, some arbitrary lines must be drawn, and surely no line will be able to properly account for the differences between individuals. For instance, if all people develop at different rates, then will not any age distinction necessarily be unfair to people who have developed less quickly? While this is true, it is not an argument for leaving the age of majority at eighteen. Even if government and policy must draw some lines, legislators should seek to draw those lines according to accepted science. By moving the age of majority back to twenty-five, policy would best reflect what the scientific community has come to know about how the brain works. This would ensure that people who commit crimes are considered in the context of their lessened culpability, and it will prevent individuals from making the sorts of mistakes that tend to accompany youth.
- Arain, Mariam et al. “Maturation of the adolescent brain.” Neuropsychiatr Dis Treat. 2013; 9: 449–461. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3621648/
- Candy, Brian (2011). “Brain Maturity Extends Well Beyond Teen Years.” NRP. Retrieved from npr.org/templates/story/story.php?storyId=141164708
- Casey, B.J; Jones, Rebecca M; hare, Todd, A. “The Adolescent Brain.” Ann N Y Acad Sci. 2008 Mar; 1124: 111-126.
- Johnson, Sara, B; Blum, Robert, W; Giedd, Jay, N.
“Adolescent Maturity and the Brain: The Promise and Pitfalls of Neuroscience Research
in Adolescent Health Policy.” J Adolesc Health. 2009 Sep; 45(3): 216–221. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2892678/
- Mental Health Daily (2015). “At What Age Is The Brain Fully Developed? Retrieved from
- Steinburg, Laurence (2012). “Should the Science of Adolescent Brain Development Inform Public Policy?” Issues in Science and Technology. Volume XXVIII Issue 3, Spring 2012. Retrieved from http://issues.org/28-3/steinberg/
- US Legal (n.d.). “Adult Law and Legal Definition.” Retrieved from