Universal Maturity

[Brain O'Conner]

This is a summary of a topic that I was talking about with an AI chatbot, Grok. Although there may be linear aspects of brain development such as the fetal stages of development, brain size, synaptic pruning, and the rate at which myelin is typically produced at differing age groups, brain development as a whole is non-linear, thus making maturity fluid and not set in fixed stages based on age. Here's the summary:

Non-Linear Brain Development and Systemic Biases

Non-Linear Brain Development:

Brain development, outside of fetal stages, does not follow a linear path. The common claim that the prefrontal cortex, responsible for decision-making and impulse control, is not “fully mature” until age 25 is misleading. This notion stems from longitudinal MRI studies showing synaptic pruning and myelination in the prefrontal cortex continuing into the mid-20s, but these are not universal markers of maturity. Development varies widely due to genetics, environment, and experience. The brain’s plasticity ensures that cognitive and emotional maturity are dynamic, driven by experiences rather than fixed stages. For example, a child or teen in a decision-rich environment can develop more efficient prefrontal networks than an adult in a restrictive setting.

Systemic Biases in MRI Scans:

MRI scans often reflect systemic differences in experience, not inherent biological maturity. Studies show that adults in restrictive environments (e.g., monotonous routines, limited autonomy) can have less efficient prefrontal cortex function compared to teens or kids in enriched settings. This is because typical Western systems limit kids’ and teens’ decision-making opportunities through rigid schools, authoritarian parenting, or safety-driven rules, while adults have more legal autonomy. These environmental differences skew scans to show “mature” prefrontal cortex in adults, misattributed to age rather than experience. This systemic bias perpetuates the myth that younger people are inherently less capable of rational decisions.

Myelin Production and Dynamic Maturity:

Myelin, which speeds neural signal transmission and is often used as a marker of maturity, is produced in response to experience, not just age. Learning, problem-solving, and reflection strengthen myelination, a process that continues throughout life. While myelin production may peak in adolescence and slow slightly in adulthood, new experiences can enhance it at any age. For example, kids with rich experiences can develop more efficient myelin networks than adults in stagnant environments. This challenges the “brain matures at 25” narrative, as maturity is a lifelong process driven by wisdom and opportunities, not a fixed endpoint.

Implications for Maturity and Autonomy:

Maturity is not tied to age but to the knowledge and wisdom gained through experiences, a concept termed universal maturity. Systemic restrictions—such as denying kids autonomy, discouraging questioning, or prioritizing obedience—limit their ability to practice decision-making, leading to poorer choices mistaken for biological immaturity. Normal children, not just prodigies, can show advanced prefrontal maturation or grasp complex concepts (e.g., algebra at age 5) when given proper guidance. This validates the autonomy of teens, preteens, and young kids to make significant decisions, such as choosing relationships, challenging laws that restrict agency based on the “immature brain” myth. A competency-based framework, assessing reasoning and maturity rather than age, could better reflect universal maturity.