The concept of psychological maturity has implications across both legal and social contexts, while a combination of political activism and scientific evidence continue to reshape and qualify its definition.
[5] The key to human innovation through the use of symbols and tools, therefore, is re-interpretive imitation that is "practiced, perfected, and varied in play" through extensive exploration of the limits on one's ability to interact with the world.
Evolutionary psychologists have also hypothesized that cognitive immaturity may serve an adaptive purpose as a protective barrier for children against their own under-developed meta-cognition and judgment, a vulnerability that may put them in harm's way.
Although psychological maturity is specifically grounded in the autonomy of one's decision-making ability, these outcomes are deeply embedded in not only cognition, but also in lifelong processes of emotional,[7] social and moral development.
While maturity is often termed as a label awarded to a child, research has revealed that children themselves hold a clear sense of their own autonomy and personal jurisdiction.
[17] But this same study also found that 6- to 11-year-old Canadian children rejected nondemocratic systems on the basis of violating principles of majority vote, equal representation, and right to a voice, which provides evidence for an emerging knowledge of political decision-making skills from a young age.
This period of growth is particularly important for humans, who undergo a unique four-stage pattern of development (infancy, childhood, juvenility, adolescence) that has been theorized to confer a number of evolutionarily competitive benefits (Locke & Bogin, 2006).
Human children, on the other hand, do not have an advanced motor control capable of foraging and also lack the digestive capacity for unprepared food, so they have always relied on the active involvement of their mother and other caregivers in their care into childhood.
[20] The prefrontal cortex, which is responsible for higher cognitive functions such as planning, decision-making, judgment and reasoning, develops and matures most rapidly during early adolescence, but is seen to continue into one's 20s.
[21] Accompanying the growth of the prefrontal cortex is continued synaptic pruning (the trimming of rarely used synapses) as well as increased myelination of nerve fibers in the brain, which serves to insulate and speed up signal transmission between neurons.
[23] Steinberg observes that there is close overlap in the activated brain regions for socioemotional and reward information, which may pose a challenge when making decisions in the most high-risk peer contexts.
The age of majority, the most broadly applied legal threshold of adulthood, is typically characterized by recognition of control over oneself and one's actions and decisions.
[35] The Maori of New Zealand, the Tinne Indians of the Yukon, the Chichimilia of Mexico, and the Eskimos, among other groups, all hold varyingly negative beliefs about the time of menarche and what dangers it brings.
Various branches of the military hold similar formal proving rituals, such as boot camp, that, aside from serving to train entrants, also demarcate an initial recognition of maturity in the organization, with successive experiences building upon that.
[36][37][38] However, for legal purposes, people are not considered psychologically mature enough to perform certain tasks (such as driving, consenting to sex, signing a binding contract or making medical decisions) until they have reached a certain age.