Cognitive maturation refers to the biological development of the brain by which an individual’s thinking, reasoning, and problem-solving abilities evolve and become more sophisticated as they grow older. This process is assessed by significant changes in how individuals understand abstract concepts, engage in formal operational thinking, apply reasoning skills to complex situations, and can solve problems. A cognitively immature human contributes to - through their attitudes, behaviors, dealings, responses, and languages - a poor ability to plan and make rational decisions, poor problem-solving and information-processing abilities, risk-taking behaviours, showing less impulse control, more susceptibility to negative influences and adopt peer pressure, etc.
In the last two to three decades, advances in the interdisciplinary field of cognitive and brain science have contributed greatly to our understanding of the development of the human brain and cognition. The human brain develops through a lifetime learning process of knowledge, skills, languages, habits changing attitudes, etc. However, the biological cognitive maturity of the brain reaches a certain age in life, which is not a fixed period of the chronological age of any human, but rather a biological age of the brain.
In 2020, the School of Health in Social Sciences at the University of Edinburgh UK prepared a study for consideration by the Scottish Sentencing Council, entitled ‘The development of cognitive and emotional maturity in adolescents and its relevance in judicial contexts’. According to this study, human cognitive development generally undergoes maturational change up to the age of mid to late twenties, an age range typically considered adult rather than child or adolescent. The time period for attaining cognitive maturity can vary to a large degree for every human, depending upon one’s nature (biology) of developing cognitive maturity in life and experiences faced by an individual during their childhood and adolescence.
The cognitive maturity development process can be affected by many complex environmental and biological factors like adverse childhood experiences in the form of abuse, neglect and exploitation, stress, traumatic brain injury, substance or alcohol use, pubertal hormones, genetics including psychological and psychiatric disorders, etc., and produce gender-specific implications. A human being who experiences any one or more of the underscored environmental or biological factors during childhood and adolescence may take longer time than others to develop cognitive maturity in their lifetime. Thus, the process of development of biological cognitive maturity in human beings does not specify an exact chronological age at which cognitive maturity is definitively reached at an individual level. The inter-individual variation in the timescale for the development of biological cognitive maturity is a field, that is yet to be fully explored and identified.
The definition of the child needs to be amended by eliminating the chronological age threshold and incorporating the biological mental age or cognitive maturation age along with pubertal maturity thresholds.
Biological Mental Age is a psychological concept that measures an individual’s biological cognitive maturity and ability compared to the average abilities demonstrated by others of the same chronological age. It represents the typical biological mental age at which most individuals demonstrate a comparable level of intellectual functioning. Every human has a biological mental age, which is not necessarily their chronological age. For example, a person who is chronologically 20 years old may have a biological mental age of fewer than 15 years, or a person who is chronologically 15 years old may have a biological mental age of more than 20 years.
Exact biological mental age may be assessed under the interdisciplinary field of cognitive and brain science with contributors from various fields, including psychology, neuroscience, biology, anthropology, linguistics, philosophy of mind computer science, etc. Normally, psychologists assess the biological mental age by applying various psychological tests including their live assessments of one’s attitude, behavior, emotion, and intelligence. The standardised psychological tests to determine the biological mental age are intelligence quotient (IQ) test, emotional/social/adversity intelligence tests, etc. Each test results provide its own findings in the form of thresholds on cognitive abilities and can be used aggregately to determine the biological mental age of cognitively mature and immature human beings.
The general societal perception of the child is that the child is a human being, who is innocent, irrational, and cognitively immature. Normally, people consider a transition of a child into an adult, when they undergo pubertal changes in their bodies. This is typically a teenage period of one’s life and can start before attaining eighteen years of age. Puberty is the stereotypical concept to assess the human as an adult, because a pubertally developed human may be mature in performing sexual relationships, but may not be cognitively mature enough to perform other rational acts in daily life. So, puberty is not the scientific way of defining the child.
The internationally accepted definition of a child is ‘every human being below the age of eighteen years.’ This definition emphasises the chronological age of a human being since birth but pays no consideration to the biological mental age, and cognitive maturity age of human beings. A child may have attained the biological mental age or cognitive maturity of an adult person and vice-versa. The problematic nature of definitions and perceptions about children makes children vulnerable to abuse, neglect, and exploitation across the nation.
To address the problems highlighted above, the definition of the child needs to be amended by eliminating the chronological age threshold and incorporating the biological mental age or cognitive maturation age along with pubertal maturity thresholds. Besides, this diagnosis must be assessed by a team of qualified multidisciplinary experts collaboratively, which inter alia can include psychologists (cognitive/developmental/biological), cognitive neuroscientists, developmental neurobiologists, psychiatrists (child/forensic), developmental pediatrician, linguists, anthropologist and computer scientist.
Recommendations
Based on the above discussion, I propose hypothetically following new definitions of child;
Definition-1 of Child: A child means a human being, who is pubertally immature and/or is below the biological mental age threshold of a cognitively mature human being provided that such diagnosis must be assessed by a multidisciplinary team collaboratively.
Definition-2 of Child: A child means a human being, who is pubertally immature and/or is below the age of his sufficient biological cognitive maturity provided that such diagnosis must be assessed by a multidisciplinary team collaboratively.
Definition-3 of Child: A child means a human being, whose biological mental/cognitive maturity age is below the biological age threshold of a cognitively mature human being provided that such diagnosis must be assessed by a multidisciplinary team collaboratively.