Prefrontal Cortex As A Psychological Factor For Determining Adulthood: The Need To Amend Our Laws

Have you ever wondered why a youngster’s ability to judge, make decisions, plan ahead, consider consequences, and manage emotions are not utilized by her or his brain to the extent that it will be by an adult brain? The reason is simple. Evidence by neuro science suggests that, in the human prefrontal cortex, pruning does not occur until the early 20s or later.

In approximation, the development and maturation of the prefrontal cortex is fully accomplished at the age of 25 years. At this stage, the brain stops making new neurons and changes. The development of the prefrontal cortex is very important for complex behavioural performance, as this region of the brain helps coordinate higher-order cognitive processes and executive brain functions.

The Executive brain functions are a set of supervisory mental skills needed for goal-directed behaviour, which include adaptable thinking, planning, self-monitoring, self-control, working memory, time management, etc. So, we can safely say that, teenager’s life begins at 13 years and ends at 20 years. From 21 to 24, one is basically stuck in between as an “emerging adult” because the brain is estimated to continue to develop until 25. At 25, a one is a full adult because the brain is estimated to be completely developed. Hence, the full adulthood life is attained at 25 years.

However, suffice it to say that the concept of adulthood has over the years gained legal and socio-cultural definitions. The legal definition of an adult is an individual who has reached the age of majority, which refers to the age at which a person will be defined by law to be an adult. This will be accompanied by the rights, liabilities, and responsibilities of adulthood. In most cultures it is 18 years, although there is a variation from 16 to 21 depending on the state or the country.

Similarly, the socio-cultural definition of being an adult is based on what a culture normatively views as being the required criteria for adulthood, which in turn, influences the lives of individuals within that culture. This may or may not coincide with the legal definition.[i] To every researching mind, it’s crystal clear that no country, state or culture have accepted 25 years as the threshold of adulthood and it’s unfortunately that not even our own (Nigerian) laws or that of any other countries recognise this psychological factor that defines adulthood.

Do I perceive some silent whys? Well, the reason is not farfetched. Because the age of adulthood can be physically claimed by two points in one’s life: the teenage or puberty stage, which begins at 12–20; and the brain development or full adulthood stage, which begins at 21–25 and in most rare cases 30. Unfortunately, we didn’t know about the later until recently and so we went for the former with the thought that growth was finished around 18. However, save for the above ignorance, other factors like culture and religion play into that.

Taking Nigeria as a focal point of discussion, it is therefore necessary that our laws are revisited for amendment. For instance, section 18 of the Child Rights Act of 2003 states that a child is anybody under 18 years of age, by virtue of placing the minimum age of marriage as 18 years. Similarly, in lending credence to the above Act (Child Right Act), the Sexual Offences Bill 2015, impliedly defined a child as someone below 18 years, by prohibiting sexual intercourse with anyone between the ages of 0 to 18 years. For help, Section 7 (2) of the above Act provides:

“A person who commits an offence of defilement with a child aged eleven years or less shall upon conviction be sentenced to imprisonment for life (3) A person who commits an offence of defilement with a child between the age of twelve and fifteen years is liable upon conviction to imprisonment for life (4) A person who commits an offence of defilement with a child between the age of sixteen and eighteen years old is liable upon conviction to imprisonment for life.”

Also, Section 18 (1) of Marriage Act specifies the minimum age for marriage when consent is required to be 21 years, which is in variation to the two above mention statutes. However, it’s pertinent to note that in Nigeria, the State House of Assembly can make Laws to operate in the state they serve. By Law in some Nigerian states, children as young as 12 years could still legally get married. With the Child’s Rights Act only being adopted by 24 out of the 36 States in Nigeria. State like Jigawa had opposed the Childs Rights Act pointing out that it’s controversial to the predominant religion and culture of the residents–the Muslims.[ii]

Other states that are yet to adopt the Childs Right Act includes: Bauchi, Yobe, Kano, Sokoto, Adamawa, Borno, Zamfara, Gombe, Katsina, Kebbi, and Jigawa.[iii]Be that as it may, another aspect of our law that mostly need amendment is the Section 117 (2)[iv] which impliedly recognised 18 years as the age of majority by making it the voting age.

From the above, it’s clear that it’s only the Marriage Act that recognised adulthood as someone between 21 years and above. But the question is, why should we amend our laws to accommodate age 25 or at least 21 in some cases as the threshold of adulthood? The reason is crystal clear, as elucidated above in the first two lines of the first paragraph. I dare say that it’s loud enough to the deaf and vivid to the blind that our current political problems are linked to the wrong choices of leaders which is made largely by youngsters who are immature to make decisions and consider the consequences of their actions in the long run.

 Also, the high rate of divorce is another cause for alarm. According to Abuja-based lawyer, Annnebrafa, Esq, there are over 4,000 couples applied for a divorce in the Federal Capital Territory in less than two months. This claim was made in her twitter handle in February, 2020. In her words, she tweeted “4,000 divorce applications in Abuja already and the year just started.

“Some of these marriages are less than a year old. What is really happening?”[v]Although, there’s a claim that the cause of the problem could be traced to the use of “Kayan Mata,” which literally means ‘women things’ in Hausa. The product is said to be a sex and love enhancer originally meant to bond couples as it possesses the power to improve their affections.

However, a critical look into the rate of divorce across the country points to what I called “marriage of immature couples,” a marriage where intending couples are less than 25yrs. Divorce often occasions over inability of the couples to handle emotional problems. To right all these wrongs and many others which this writer can’t mention, then there is the need to amend our laws to accommodate the true age of adulthood.


The Constitution of the Federal Republic of Nigeria acknowledge 18years as the age of majority. However, other laws like the Electoral law, Marriage law, Contract law, Criminal law et al., have different age provisions respectively for the age of majority. This present writer has pointed out the problems associated with immaturity, as defined by this writer.

Immaturity from a psychological viewpoint is the ages prior to the full development of the prefrontal cortex. There’s therefore no doubt that our laws need amendments in the area of the age of majority if we must get it right as a nation. This present writer humbly suggests that our laws should be revisited with aim to amend them, particularly the Constitution thereby setting the threshold age for majority as 21years, while that of voting age and other sensitive national affairs are raised to 25 years.

[i] Robinson, Oliver. Development through Adulthood: An Integrative Sourcebook ( Macmillan Education UK. ISBN 978-0-230-29799-9. 2012)

[ii] Abubakar Ahmadu Maishanu, ‘Jigawa assembly passes Child Rights Bill, expunges age limit for marriage.’  The Premium Time (21 Dec. 2021) <> assessed 19 April 2022

[iii] Nike Adebowale, ‘UPDATED: 11 states in northern Nigeria yet to pass child rights law — UNICEF Official’ The Premium Time (11 May 2019) <> assessed 19 April 2022

[iv] CFRN 1999

[v] Ochogwu Sunday, ‘Alarming rate of divorce in Abuja, other states traced to use of Kayan Mata’ Daily Post (5 March 2021) <>assessed 19 April 2022

About the author.

Nweke Chinonso is a law student, legal researcher and article writer; with penchant for Artificial Intelligence Law, Space Law, Environmental Law and International Humanitarian Law. He can be reached at [email protected]

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