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An adult is an animal that has reached full growth.[1] The biological definition of adult is an organism that has reached sexual maturity and thus capable of reproduction.

In the human context, the term adult has meanings associated with legal and social concepts. In contrast to a non-adult or "minor", a legal adult is a person who has attained the age of majority and is therefore regarded as independent, self-sufficient, and responsible. They may also be regarded as "majors". The typical age of attaining adulthood for humans is 18 years, although definition may vary by country.

Human adulthood encompasses psychological adult development. Definitions of adulthood are often inconsistent and contradictory; a person may be biologically an adult, and have adult behavior, but still be treated as a child if they are under the legal age of majority. Conversely, one may legally be an adult but possess none of the maturity and responsibility that may define an adult character.

In different cultures, there are events that relate passing from being a child to becoming an adult or coming of age. This often encompasses passing a series of tests to demonstrate that a person is prepared for adulthood, or reaching a specified age, sometimes in conjunction with demonstrating preparation. Most modern societies determine legal adulthood based on reaching a legally specified age without requiring a demonstration of physical maturity or preparation for adulthood.

Biological adulthood

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Historically and cross-culturally, adulthood has been determined primarily by the start of puberty (the appearance of secondary sex characteristics such as menstruation and the development of breasts in women, ejaculation, the development of facial hair, and a deeper voice in men, and pubic hair in both sexes).[2][3] In the past, a person usually moved from the status of child directly to the status of adult, often with this shift being marked by some type of coming-of-age test or ceremony.[4] During the Industrial Revolution, children went to work as soon as they could in order to help provide for their family. There was not a huge emphasis on school or education in general. Many children could get a job and were not required to have experience as adults are nowadays. In recent years, studies of adulthood have identified characteristic traits that go far beyond mere physical maturity.[5] These markers for a full, mentally developed, adult include traits of personal responsibilities in multiple aspects of life.

Although few or no established dictionaries provide a definition for the two-word term biological adult, the first definition of adult in multiple dictionaries includes "the stage of the life cycle of an animal after reproductive capacity has been attained".[6][7] Thus, the base definition of the word adult is the period beginning at physical sexual maturity, which occurs sometime after the onset of puberty. Although this is the primary definition of the base word "adult", the term is also frequently used to refer to social adults. The two-word term biological adult stresses or clarifies that the original definition, based on physical maturity (i.e. having reached reproductive competency), is being used.[8]

The time of puberty varies from child to child, but usually begins between 10 and 12 years old. Girls typically begin the process of puberty at age 10 or 11, and boys at age 11 or 12.[9][10][11] Girls generally complete puberty by 15–17, and boys by age 16 or 17.[11][12] Nutrition, genetics and environment also usually play a part in the onset of puberty.[13] Girls will go through a growth spurt and gain weight in several areas of their body. Boys will go through similar spurts in growth, though it is usually not in a similar style or time frame. This is due to the natural processes of puberty, but genetics also plays a part in how much weight they gain or how much taller they get.[14]

One recent area of debate within the science of brain development is the most likely chronological age for full mental maturity, or indeed, if such an age even exists. Common claims repeated in the media since 2005 (based upon interpretations of imaging data) have commonly suggested an "end-point" of 25, referring to the prefrontal cortex as one area that is not yet fully mature at the age of 18. However, this is based on an interpretation of a brain imaging study by Jay Giedd, dating back to 2004 or 2005, where the only participants were aged up to 21 years, and Giedd assumed this maturing process would be done by the age of 25 years, whereas more recent studies show prefrontal cortex maturation continuing well past the age of 30 years, marking this interpretation as incorrect and outdated.[15][16][17][18][19][20][21]

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Main article: Age of majority

Legally, adulthood typically means that one has reached the age of majority – when parents lose parental rights and responsibilities regarding the person concerned.[22] Depending on one's jurisdiction, the age of majority may or may not be set independently of and should not be confused with the minimum ages applicable to other activities, such as engaging in a contract, marriage, voting, having a job, serving in the military, buying/possessing firearms, driving, traveling abroad, involvement with alcoholic beverages, smoking, sexual activity, gambling, being a model or actor in pornography, running for president, etc. Admission of a young person to a place may be restricted because of danger for that person, concern that the place may lead the person to immoral behavior, or because of the risk that the young person causes damage (for example, at an exhibition of fragile items).

One can distinguish the legality of acts of a young person, or of enabling a young person to carry out that act, by selling, renting out, showing, permitting entrance, allowing participation, etc. There may be distinction between commercially and socially enabling. Sometimes there is the requirement of supervision by a legal guardian, or just by an adult. Sometimes there is no requirement, but rather a recommendation.

Using the example of pornography, one can distinguish between:

  • being allowed inside an adult establishment
  • being allowed to purchase pornography
  • being allowed to possess pornography
  • another person being allowed to sell, rent out, or show the young person pornography, see disseminating pornography to a minor
  • being a pornographic actor: rules for the young person, and for other people, regarding production, possession, etc. (see child pornography)

With regard to films with violence, etc.:

  • another person being allowed to sell, rent out, or show the young person a film; a cinema being allowed to let a young person enter

The age of majority ranges internationally from ages 15 to 21, with 18 being the most common age. Nigeria, Mali, Democratic Republic of Congo and Cameroon define adulthood at age 15, but marriage of girls at an earlier age is common.[23]

In most of the world, the legal adult age is 18 for most purposes, with some notable exceptions:

  1. The legal age of adulthood in British Columbia, New Brunswick, Newfoundland and Labrador, Northwest Territories, Nova Scotia, Nunavut, and Yukon in Canada is 19 (though there are some exceptions in which Canadians may be considered legal adults in certain situations like sexual consent, which is age 16, and criminal law, federal elections and the military, which is at 18);[24][25]
  2. The legal age of adulthood in Nebraska and Alabama in the United States is 19.[26]
  3. The legal age of adulthood in South Korea is 19.
  4. The legal age of adulthood in Mississippi and Puerto Rico in the U.S. and Bahrain is 21.

Prior to the 1970s, young people were not classed as adults until 21 in most western nations. For example, in the United States, young citizens could not vote in many elections until 21 until July 1971 when the 26th Amendment passed mandating that the right to vote cannot be abridged for anyone 18 or older. The voting age was lowered in response to the fact that young men between the ages of 18 and 21 were drafted into the army to fight in the Vietnam War, hence the popular slogan "old enough to fight, old enough to vote" [27]

Young people under 21 in the US could also not purchase alcohol, purchase handguns, sign a binding contract, or marry without permission from parents. After the voting age was lowered, many states also moved to lower the drinking age (with most states having a minimum age of 18 or 19) and also to lower the age of legal majority (adulthood) to 18. However, there are legal activities where 18 is not the default age of adulthood. There are still some exceptions where 21 (or even higher) is still the benchmark for certain rights or responsibilities. For example, in the US the Gun Control Act of 1968 prohibits those under 21 from purchasing a handgun from a federally licensed dealer (although federal law makes an exception for individuals between the ages of 18 and 20 to obtain one from a private dealer if state law permits.) [28]

As of July 1984, the National Minimum Drinking Age Act mandated that all states raise their respective drinking ages to 21 to create a uniform standard for legally purchasing, drinking, or publicly possessing alcohol with exceptions made for consumption only in private residences under parental supervision and permission. This was done in response to reducing the number of drunk driving fatalities prevalent among young drivers. States that choose not to comply can lose up to 10% of highway funding.[29]

The Credit Card Act of 2009 imposed tougher safeguards for young adults between the ages of 18 and 20 obtaining a credit card. Young adults under the age of 21 must either have a co-signer 21 or older or show proof (usually a source of income) that they can repay their credit card balance.[30] Unless that requirement is met, one must wait until 21 to be approved for a credit card on their own.

The Affordable Care Act of 2010 expands the age that young adults can remain on their parent's health insurance plan up to age 26.[31]

As of December 2019, the federal government raised the legal age to purchase tobacco and vaping products from 18 to 21.[32] In states where recreational marijuana is legalized, the default age is also 21, though those younger may be able to obtain medical marijuana prescriptions or cards upon seeing a physician.[33]

Gambling also varies from 18 to 21 depending on the state and many rental car companies do not rent cars to those under 21 and have surcharges for drivers under 25 (although this is not codified, and is company policy).

In Quebec, Canada the Quebec legislature in 2020 raised the age one could purchase recreational marijuana from 18 to 21 stepping out of line with most of the country that set a minimum age of 19 (except Alberta, which is 18.) The Quebec government cited the risk that marijuana poses to the brain development of people under 21 as justification for the age raise.[34]

In March 2021, the state of Washington in a 5–4 decision, justices in the Supreme Court of the State of Washington tossed the life without parole sentences of a 19-year-old and a 20-year-old convicted in separate cases of first-degree aggravated murder decades ago, saying, as with juveniles, the court must first consider the age of those under 21 before sentencing them to die behind bars. This comes at a time when there are ongoing debates about whether those between 18 and 20 should be exempted from the death penalty.[35][36][37][38]

In Germany, courts largely sentence defendants under the age of 21 according to juvenile law in a bid to help them reintegrate into society and mete out punishments that fit the crime as well as the offender.

In May 2021, the state of Texas raised the age that one can be an exotic dancer and work and patronize sexually oriented businesses from 18 to 21.[39]

In the UK, there have been many proposals to raise the age that one can buy tobacco from 18 to 21 in an attempt to curb teen and young adult use to get to a "smoke-free" UK by 2030.[40] All of these laws made over the years reflect the growing awareness that young adults, while not children, are still in a transitional stage between adolescence and full adulthood and that there should be policy adjustments or restrictions where necessary, especially where it pertains to activities that carry certain degrees of risk or harm to themselves or others.[41]

At the same time, however, even though the generally accepted age of majority is 18[42] in most nations, there are rights or privileges afforded to adolescents who have not yet reached legal adulthood. In the United States, youth are able to get a part-time job at 14 provided they have a work permit. At 16, one is able to obtain a driver's permit or license depending on state laws and is able to work most jobs (except ones requiring heavy machinery) and consent to sexual activity (depending on the state). At 17, one is able to enlist in the armed forces with parental consent although they cannot be deployed to be in combat roles until age 18.

The voting age for local elections in most American cities is 18. But in five localities nationwide — four of which are in Maryland — 16 and 17-year-olds are eligible to vote. The cities are Takoma Park, Riverdale, Greenbelt, and Hyattsville.[43]

In 2020, students 16 or older in Oakland, California gained the right to vote in school board elections. There is a growing movement to lower the voting age in the US and many other countries from 18 to 16 in hopes of engaging the youth vote and encouraging greater electoral participation. Some countries already have a voting age of 16 which include Austria, Scotland, Argentina, Brazil, Wales, Cuba, and Ecuador.

In Germany, one can purchase beer and wine at the age of 16 although they cannot purchase spirits or hard liquor until 18. The age of consent in Germany is 14 if both partners are under 18. Sexual activity with a person under 18 is punishable if the adult is a person of authority over the minor in upbringing, education, care, or employment.

Social construction of adulthood

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In contrast to biological perspectives of aging and adulthood, social scientists conceptualize adulthood as socially constructed.[44][45] While aging is an established biological process, the attainment of adulthood is social in its criteria. In contrast to other perspectives that conceptualize aging and the attainment of adulthood as a largely universal development, regardless of context, nation, generation, gender, race, or social class. Social scientists regard these aspects as paramount in cultural definitions of adulthood.[46]

Further evidence of adulthood as a social construction is illustrated by the changing criteria of adulthood over time. Historically, adulthood in the U.S. has rested on completing one's education, moving away from the family of origin, and beginning one's career.[47][48][49] Other key historical criteria include entering a marriage and becoming a parent. These criteria are social and subjective; they are organized by gender, race, ethnicity, and social class, among other key identity markers. As a result, particular populations feel adult earlier in the life course than do others.[50][51][52][53]

Contemporary experiences of and research on young adults today substitute more seemingly subjective criteria for adulthood which resonate more soundly with young adults' experiences of aging.[51][54] The criteria are marked by a growing "importance of individualistic criteria and the irrelevance of the demographic markers of normative conceptions of adulthood."[55] In particular, younger cohorts' attainment of adulthood centers on three criteria: gaining a sense of responsibility, independent decision-making, and financial independence.[56][57]

Jeffrey Arnett, a psychologist and professor at Clark University in Massachusetts, studied the development of adults and argues that there is a new and distinct period of development in between adolescence and adulthood. This stage, which he calls "emerging adulthood", occurs between the ages of 18 and 25.[58] Arnett describes these individuals as able to take some responsibility for their lives, but still not completely feeling like an adult. Arnett articulates five distinct features that are unique to this period of development: identity exploration, feeling in between, instability, self-focus, and having possibilities.[59] Arnett makes it clear that these 5 aspects of emerging adulthood are only relevant during the life stage of emerging adulthood.[60]

The first feature, identity exploration, describes emerging adults making decisions for themselves about their career, education, and love life. This is a time of life when a young person has yet to finalize these decisions but are pondering them, making them feel somewhere in between adolescent and adult. This leads into a second feature of this phase of life—feeling in between. Emerging adults feel that they are taking on responsibilities but do not feel like a 'full' adult quite yet. Next, the instability feature notes that emerging adults often move around after their high school years whether that is to college, friends' houses, or living with a romantic partner, as well as moving back home with their parents/guardians for a time. This moving around often ends once the individual's family and career have been set. Tagging along with the instability feature is having self-focus. Emerging adults, being away from their parental and societal routines, are now able to do what they want when they want and where they want before they are put back into a routine when they start a marriage, family, and career. Arnett's last feature of emerging adulthood, an age of possibilities, characterizes this stage as one where "optimism reigns".[59] These individuals believe they have a good chance of turning out better than their parents did.[59]

Religion

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According to Jewish tradition, adulthood is reached at age 13 for Jewish boys and 12 for Jewish girls in accordance with the Bar or Bat Mitzvah;[61][62] they are expected to demonstrate preparation for adulthood by learning the Torah and other Jewish practices. The Christian Bible and Jewish scripture contain no age requirement for adulthood or marrying, which includes engaging in sexual activity.

The 1983 Code of Canon Law states, "A man before he has completed his sixteenth year of age, and likewise a woman before she has completed her fourteenth year of age, cannot enter a valid marriage".[63] According to The Disappearance of Childhood by Neil Postman, the Christian Church of the Middle Ages considered the age of accountability, when a person could be tried and even executed as an adult, to be age 7. While certain religions have their guidelines on what it means to be an adult, generally speaking, there are trends that occur regarding religiosity as individuals transition from adolescence to adulthood. The role of religion in one's life can impact development during adolescence.[64] The National Library of Medicine (NCBI) highlights some studies that show rates of religiosity declining as people move out of the house and live on their own. Oftentimes when people live on their own, they change their life goals and religion tends to be less important as they discover who they are. Other studies from the NCBI show that as adults get married and have children they settle down, and as they do, there tends to be an increase in religiosity. Everyone's level of religiosity builds at a different pace, meaning that religion relative to adult development varies across cultures and time.[65]

See also

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References

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Adult

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An is a individual who has attained physical maturity following , characterized by the completion of , skeletal growth, and reproductive capability, typically emerging in the late teens. Legally, adulthood is defined by the age of majority, the threshold at which a assumes full and responsibilities under , most commonly set at 18 years in jurisdictions worldwide, though varying by context such as contracts or . Biologically and neurologically, however, full maturation extends beyond this, with the —governing impulse control, planning, and risk assessment—undergoing significant development into the mid-20s, underscoring that chronological markers alone imperfectly capture readiness for adult responsibilities. Psychologically, defining traits include self-sustaining , for one's actions, and the ability to form stable interpersonal commitments, often delayed in modern societies due to extended and economic dependencies, giving rise to the concept of "emerging adulthood" as a prolonged transitional phase. These facets highlight ongoing debates over adulthood's boundaries, with empirical data prioritizing functional capacities over arbitrary age thresholds to assess true maturity.

Biological Foundations

Physical and Reproductive Maturity

Physical maturity in humans is primarily indicated by the completion of longitudinal skeletal growth, achieved through the and fusion of epiphyseal plates in long bones, which halts further height increase. This process concludes in late to early adulthood, with skeletal maturity generally reached by approximately age 20. Females typically experience earlier closure, often between ages 15 and 19 for major lower limb bones like the and , influenced by estrogen-driven epiphyseal fusion during . Males exhibit delayed closure, with full fusion in comparable bones by age 19, extending to early 20s for sites like the distal due to prolonged effects on growth plates. Factors such as , , and hormonal levels contribute to individual variation, but empirical radiographic studies confirm sex-based dimorphism, with males achieving peak mass later. Reproductive maturity builds on pubertal onset, marking the transition to full production and capacity without the inefficiencies of early . In females, occurs at an average age of 12.4 years in developed populations, but ovulatory cycles become consistently regular by late teens, aligning with peak in the early 20s, where monthly conception probability exceeds 25%. This peak reflects optimal oocyte quality and quantity, declining post-30 due to accelerating , with conception rates dropping below 5% per cycle by age 40. In males, initiates around age 13-14, but semen parameters like motility and DNA integrity optimize in the 20s to early 30s, supporting mature reproductive competence. Full reproductive maturity thus coincides with physical stabilization, enabling sustained before age-related declines in viability, as evidenced by longitudinal cohort data.

Neurological Development

The achieves structural and functional maturity gradually, with significant neurological development extending from into the early 20s, as evidenced by longitudinal (MRI) studies tracking gray and white changes. These studies reveal ongoing refinement in cortical thickness, particularly in association areas like the , which supports such as , impulse control, and —processes that lag behind subcortical regions involved in reward processing. By the mid-20s, these regions exhibit stabilized connectivity, marking a transition to adult-like neural architecture optimized for sustained attention and self-regulation. Key mechanisms include , which selectively eliminates weaker neural connections to enhance efficiency, and myelination, which insulates axons to accelerate ; both processes persist into early adulthood, reconfiguring limbic-prefrontal circuits for integrated . Empirical data from cohorts indicate that prefrontal gray matter volume peaks and then declines slightly after , reflecting pruning's role in streamlining overabundant synapses formed earlier in life. White matter integrity, driven by myelination, continues to increase into the 20s, correlating with improved and reduced observed in behavioral tasks. This protracted timeline underscores causal links between neural maturation and behavioral adulthood markers, such as diminished sensation-seeking, though individual variability exists due to genetic, environmental, and experiential factors. Post-maturity, adult brains retain for adaptation—evidenced by hippocampal in response to learning—but at diminished rates compared to , prioritizing stability over rapid rewiring. Disruptions, like those from or substance use during this window, can impair final connectivity, with longitudinal evidence linking early interventions to better outcomes.

Psychological and Cognitive Aspects

Emotional Regulation and Impulse Control

The maturation of the (PFC), particularly its dorsolateral and ventrolateral subdivisions, underpins adult capacities for emotional regulation by enabling top-down modulation of limbic structures such as the , which drive affective responses. This neural integration allows adults to employ cognitive reappraisal and suppression strategies more effectively than , reducing emotional reactivity to stressors. studies demonstrate that PFC-amygdala connectivity strengthens progressively from late into the mid-20s, correlating with diminished in tasks. Impulse control in adults manifests as enhanced executive function, including the inhibition of immediate rewards in favor of long-term gains, as evidenced by performance on delay paradigms where adults exhibit steeper value gradients for future outcomes compared to adolescents. This developmental shift aligns with and myelination in the PFC, processes that peak around age 25 and facilitate sustained attention and response inhibition. Twin studies estimate heritability at approximately 50-60%, yet environmental factors like and early experiences modulate its expression, with childhood predicting adult outcomes such as span and socioeconomic attainment. Laurence Steinberg's elucidates how adolescent stems from an imbalance between a hyper-responsive (ventral ) and underdeveloped control mechanisms, which equilibrates by early adulthood, reducing peer-influenced risk-taking by up to 50% in experimental settings. Empirical data from longitudinal cohorts show self-reported declining sharply between ages 15-19 and stabilizing in the 20s, with meta-analyses confirming stronger inverse links between and deviance in adults. differences persist into adulthood, with males displaying elevated sensation-seeking but comparable impulse control trajectories after . Deficits in adult emotional and impulse control, when present, often trace to atypical neurodevelopment, such as delayed PFC maturation from early life adversity, increasing to disorders like borderline . Interventions targeting these faculties, including cognitive-behavioral , yield moderate effect sizes (d ≈ 0.4) in enhancing among young adults, underscoring the plasticity retained post-adolescence.

Decision-Making and Risk Assessment

The maturation of the (PFC) in early adulthood, typically completing around age 25, underpins advanced and by enhancing such as foresight, , and probabilistic evaluation. This neural development enables adults to integrate cognitive deliberation with emotional inputs, prioritizing long-term consequences over immediate gratification, in contrast to the adolescent imbalance favoring limbic-driven reward sensitivity. studies confirm that adult PFC activation during risky choices correlates with reduced and more accurate probability weighting, as evidenced by functional MRI data from tasks involving uncertain outcomes. Empirical research using paradigms like the and Balloon Analogue Risk Task demonstrates that adults exhibit lower rates of suboptimal risky selections compared to adolescents, who overvalue potential gains while underestimating losses, particularly under social pressure. A within-subject study of 14- to 25-year-olds found adolescents more prone to risks with unlikely but severe negative outcomes, attributing this to immature PFC-mediated inhibitory processes that stabilize by full adulthood. Meta-analyses of age-related differences further indicate that, while not uniform across all tasks, adults consistently show superior performance in scenarios demanding sustained risk-reward appraisal, with effect sizes reflecting PFC maturation's causal role in curbing sensation-seeking peaks. Adult also benefits from refined executive function integration, allowing for context-dependent adjustments, such as heightened aversion to losses in economic or domains. Longitudinal data from neurocognitive assessments reveal that post-adolescent improvements in impulse control—measured via tasks—correlate with fewer real-world maladaptive decisions, like or substance initiation, underscoring the PFC's role in causal realism for behavioral outcomes. However, individual variability persists due to factors like genetic predispositions and environmental exposures, though population-level trends affirm adulthood as the threshold for reliable, evidence-based calibration.

Age of Majority

The age of majority denotes the legally established age at which an individual attains full adult status, acquiring the capacity to exercise civil rights and bear responsibilities independently of parental or guardian oversight, including the ability to enter binding contracts, sue or be sued, and manage without restrictions applicable to minors. This threshold terminates minority status and aligns with the cessation of parental legal authority in most contexts, though certain rights like alcohol consumption or may remain restricted beyond it in specific jurisdictions. Historically rooted in English , the was set at 21, a convention inherited from feudal traditions where it corresponded to the completion of apprenticeship terms or military service eligibility, with precedents traceable to practices that varied but often emphasized physical maturity around 17–25 for civic duties. , this 21-year standard persisted until the of the 26th Amendment on July 1, 1971, which lowered the federal to 18 and prompted most states to align the general accordingly, reflecting arguments that those eligible for military during the should possess broader civic capacities. Similar reductions occurred globally post-World War II, driven by evolving views on maturity amid expanded and democratic participation, though remnants of higher ages endure in select legal domains. As of 2025, the age of majority stands at 18 in the of countries, including all but a few exceptions among nations; for instance, it remains 19 in parts of and , and was 20 in until a 2022 reform lowered it to 18 for most purposes. In the United States, 47 states and the District of Columbia set it at 18, with and at 19, and at 21, though overrides for voting and at 18. Internationally, the Convention on the Rights of the , ratified by 196 countries as of 2023, defines a child as any person under 18 unless national specifies earlier majority, establishing 18 as a normative benchmark for protections while accommodating jurisdictional variances. Variations persist due to cultural, religious, or factors; for example, in some Islamic jurisdictions under Sharia-influenced codes, may align with onset for specific rites, though civil ages often default to 18 or 21. statutes in places like the U.S. allow minors to petition for early recognition based on demonstrated self-sufficiency, such as through , , or decree, underscoring that the age serves as a rather than an absolute biological or cognitive determinant. These frameworks reflect pragmatic legal constructs rather than uniform empirical markers of maturity, as neurological development into the mid-20s challenges rigid cutoffs but prioritizes societal consistency in allocation. In most common law jurisdictions, such as the United States and the United Kingdom, individuals attain the legal capacity to enter into binding contracts upon reaching the age of majority, which is statutorily set at 18 years old. Contracts entered into by minors under this age are generally voidable at the minor's discretion, allowing disaffirmation either before or within a reasonable time after reaching majority, though exceptions apply for necessities like food, shelter, or employment contracts that courts may enforce to prevent unjust enrichment. This presumption of capacity for adults stems from the view that maturity confers the cognitive and volitional competence required for mutual assent, as articulated in doctrines like those under the Restatement (Second) of Contracts, which emphasize understanding the nature and consequences of obligations. Exceptions to adult capacity arise primarily from mental incompetence, where an individual lacks the mental ability to comprehend the contract's terms due to conditions such as severe , , or acute intoxication. Such contracts are typically voidable by the incompetent party or their guardian, but only if incompetence is proven—often requiring judicial determination rather than mere —and the other party lacked of the incapacity. For instance, under laws modeled on principles, a contract remains enforceable if the adult appeared rational at formation, shifting the burden to demonstrate defect via medical evidence or prior of incompetency. Contracts for necessities may still bind even incompetent adults to avoid exploitation, reflecting a balance between and protection. Capacity for consent, encompassing in medical, research, or personal decisions, follows a parallel framework: adults are presumed competent unless a declares otherwise, enabling independent authorization without surrogate involvement. Minors generally lack this capacity, necessitating parental or guardian consent for treatments, though statutes in 14 U.S. states and similar provisions elsewhere recognize "mature minor" exceptions for emancipated youth or specific scenarios like reproductive care, where judicially assessed understanding suffices. In , jurisdictions worldwide set the age between 12 and 21, with most clustering at 14–16, but adults above the age of face no age-based restrictions, presuming full volitional control absent or incapacity. Internationally, while the age of majority for contracts aligns at 18 in most nations under civil and systems, variations exist—such as 21 in parts of the or 19 in for certain civil acts—often tied to cultural or religious norms rather than empirical maturity thresholds. Consent capacities show greater divergence: medical consent for adults is universally presumed, but ages differ markedly, with lower thresholds in (e.g., 14 in ) versus 18 in , underscoring that legal adulthood prioritizes contractual over uniform consent benchmarks. These frameworks prioritize empirical assessments of comprehension over chronological proxies alone, though critiques note that rigid age cutoffs may overlook neurological variances persisting into the mid-20s.

Social and Cultural Dimensions

Traditional Markers of Adulthood

In historical and anthropological contexts, traditional markers of adulthood centered on biological reproductive capacity, the assumption of and economic roles, and formalized social transitions, reflecting societies' emphasis on , , and communal contribution. served as a primary biological threshold, with medieval and ecclesiastical doctrine setting the boundary at age 12 for girls and 14 for boys, when individuals gained capacities for , legal responsibility, confession, and eucharistic participation. This alignment with physical maturity enabled contributions to labor, such as agricultural work from age 15 in medieval . Socially, marriage marked a pivotal transition, historically linking individuals—especially women—to adult status through household establishment and spousal obligations, a pattern observed globally from antiquity through the early 20th century in the United States. Parenthood reinforced this by demonstrating fertility and caregiving competence, while economic self-sufficiency—via completing apprenticeships, entering stable trades, or leaving parental homes—signaled independence from familial dependence. In pre-modern Western societies, these milestones often preceded formal legal adulthood, which under English common law stood at 21 for inheritance and contracts, though Roman law recognized partial maturity at 15 with full rights at 25. Cross-culturally, rites of passage ritually affirmed these markers, testing endurance, skill, or spiritual insight to prepare youth for adult duties. Among the Sateré-Mawé of the , boys underwent multiple stings from bullet ants in glove rituals to prove resilience, typically around age 13-18. Native American vision quests isolated adolescents in nature for days to seek personal guardians, denoting readiness for tribal roles. In Jewish tradition, the Bar Mitzvah for boys at age 13 imposed religious obligations, symbolizing moral accountability. These ceremonies, varying by ecology and subsistence—endurance tests in groups versus skill demonstrations in agrarian ones—underlined adulthood as earned through demonstrated capability rather than chronological age alone.

Critiques of Emerging Adulthood

Critics of the emerging adulthood theory, first articulated by Jeffrey Arnett in 2000, argue that it lacks sufficient empirical support and rests on flawed methodology, rendering it more myth than established developmental stage. Larry Nelson's 2014 analysis highlights that Arnett's foundational claims derive from qualitative interviews with approximately 300 young people, predominantly college-educated and urban, which fail to represent broader populations or demonstrate distinct, age-graded characteristics separating this period from or young adulthood. This approach, critics contend, conflates descriptive trends in delayed role transitions—such as later and parenthood in affluent societies—with evidence of a novel psychological phase, ignoring historical precedents like extended apprenticeships in pre-industrial eras where similar delays occurred without being theorized as a "stage." A central objection is the theory's limited applicability across socioeconomic classes, with detractors asserting it primarily describes the experiences of middle- and upper-middle-class who can afford extended and , while overlooking those compelled into adult responsibilities sooner. National U.S. from the early 2010s reveal that working-class individuals aged 18-29 report higher rates of full-time , , and parenthood—markers of traditional adulthood—compared to college attendees, who exhibit greater instability and self-focus as theorized. Critics like and others argue this undermines claims of universality, as lower-income face economic pressures that truncate , leading to earlier maturity rather than a prolonged "emerging" phase. Similarly, cultural critiques emphasize its Western bias: in low-income or non-industrialized countries, transitions to adult roles like and entry occur by the late teens, with median ages under 20 in parts of and as of 2015, contradicting the theory's portrayal of ages 18-29 as exploratory across humanity. The theory is further faulted for potentially normalizing dysfunction by framing societal delays—driven by factors like rising education costs and economic uncertainty—as developmentally adaptive, which may erode incentives for responsibility and prolong dependence. Nelson posits that this narrative imposes emotional burdens, such as heightened anxiety from indefinite identity quests, and economic costs, including deferred savings and productivity losses, on youth already navigating stagnant wages and housing unaffordability; from 2014 showed 52% of 18-24-year-olds living with parents, a figure critics link to policy failures rather than inherent maturation needs. In this view, emphasizing "emerging" traits like instability discourages causal interventions, such as vocational training or family formation incentives, that historically accelerated maturity. Empirical reviews, including those questioning its scientific merit, reinforce that without longitudinal isolating emerging adulthood from variables like parental support, the theory risks perpetuating a self-fulfilling delay in high-resource contexts.

Transitions and Responsibilities

Economic Independence

Economic independence, a core marker of adulthood, refers to the capacity of individuals to financially support themselves without reliance on parental, familial, or governmental assistance, typically achieved through stable , sufficient for , and independent housing. Surveys indicate that over 90% of Americans view full-time as essential to adulthood, while more than 80% consider moving out of the parental home a key . This self-sufficiency enables , savings, and long-term planning, distinguishing adults from dependents in economic terms. In the United States, young adults are reaching economic independence later than in previous generations. In 2021, only 60% of 25-year-olds were financially independent, compared to higher rates in earlier decades, with full-time employment among this group at 66%, down from 73% in 1980. By age 22, just 24% achieved financial independence in 2018, reflecting prolonged dependence amid rising education costs and entry-level wage stagnation. Trends since the 1970s show declining economic self-sufficiency, with fewer young adults securing full-time jobs or independent households by their mid-20s, even after adjusting for education levels. In Europe, the average age for leaving the parental home—often tied to financial viability—is 26, rising to late 20s or early 30s in southern and eastern countries due to housing scarcity and labor market rigidity. Factors delaying economic independence include extended higher education, burdens averaging over $30,000 per borrower in the U.S., and mismatched skills in a service-oriented , which reduce entry into stable, high-wage roles. Labor market shifts since the 1980s, including and , have eroded jobs that once provided quick paths to self-sufficiency for non-college graduates. Among 14- to 24-year-olds, fewer than 25% are fully financially independent from family, with many in precarious gig or part-time work that fails to cover costs. Achieving economic independence correlates with reduced risk and greater life stability, as full-time work and residential predict better outcomes regardless of era. However, in 2005, while 84% of 25- to 34-year-olds lived independently, recent data show reversals, with multi-generational households rising due to economic pressures rather than cultural choice alone. This delay challenges traditional adulthood timelines, as financial dependence extends vulnerability to economic downturns and hinders formation.

Family and Reproductive Roles

Adults assume primary reproductive roles during their biologically optimal childbearing years, with female peaking between the late teens and late 20s, when egg quantity and quality are highest, yielding the lowest risks of chromosomal abnormalities and . Male similarly peaks around ages 25-29, with subsequent declines in sperm quality and DNA integrity accelerating after 35. These peaks align with adulthood's onset, enabling pair-bonding and production under conditions of physical maturity and resource accumulation, though modern socioeconomic factors often delay realization of these roles until after peak , correlating with reduced conception rates and increased reliance on assisted reproductive technologies. In family formation, adults increasingly enter or later, with the U.S. median age at first reaching 30.6 years for men and 28.7 for women in 2023, up from 26.1 and 22.0 in 1890. This postponement contributes to below-replacement rates in developed nations, where global totals averaged 2.3 children per woman in 2023, half the 1950s figure of 4.9, driven by extended education, career , and costs rather than inherent biological shifts. has risen as a precursor to or substitute for , comprising over half of U.S. unions with children by the , yet such arrangements exhibit higher dissolution rates than marital ones, potentially destabilizing early child-rearing environments. Parenting constitutes a core adult responsibility, involving provisioning, , and protection of dependents, with empirical data indicating dual-parent households—predominantly married—yield superior child outcomes in and behavioral adjustment compared to single-parent structures. In developed countries, fathers' involvement in childcare has increased, with surveys showing 58% of U.S. fathers reporting parenting as harder than anticipated, alongside mothers' 66%, reflecting intensified demands amid smaller family sizes. Adults also navigate extended kin roles, such as grandparenting, which supports intergenerational stability but strains resources when adult rises, as projected with trajectories below 1.7 in nations like the U.S. by the late 2020s.

Challenges and Pathologies

Factors Delaying Adulthood

Economic pressures, including escalating costs and stagnant , have significantly postponed young adults' achievement of and , the median age for first-time homebuyers rose from 29 in 1980 to 36 in 2023, driven by housing affordability challenges that make unattainable for many without substantial parental support or dual incomes. Similarly, burdens, averaging $37,000 per borrower as of 2023, compel extended reliance on family resources, delaying milestones like moving out. These factors reflect broader labor market shifts, where entry-level wages have failed to keep pace with in essentials like rent and groceries, as evidenced by Census Bureau analyses of delayed . Prolonged educational trajectories exacerbate these delays by extending the period of dependency before entry. The average age of completion has increased to 27 for bachelor's degrees in recent cohorts, as young adults pursue advanced credentials amid competitive job markets demanding specialized skills. This extension correlates with lower rates of full-time among 21-year-olds, dropping from higher levels in 1980, per Research data, as graduates face or roles insufficient for self-sufficiency. Social norms have shifted to normalize delayed , treating and parenthood as "capstone" events contingent on prior rather than parallel to it. U.S. marriage rates for ages 25-29 fell to 29% in 2023 from 50% in prior decades, with surveys attributing this to intentional postponement for career establishment. Greater cultural acceptance of multigenerational living, coupled with modest effects from college debt on independent moves, sustains co-residence with parents into the late 20s. Overprotective parenting practices contribute by fostering reduced resilience and decision-making . Empirical links exist between such styles—characterized by excessive intervention—and heightened anxiety, depression, and low in emerging adults, hindering risk-taking essential for milestones like relocation or . Studies on early maladaptive schemas show correlations with maternal overprotection and adult emotional dependency, amplifying vulnerability to economic stressors.

Societal and Individual Consequences

Delayed achievement of traditional adulthood milestones, such as economic and formation, has been associated with elevated risks of disorders in young adults, with three-quarters of lifetime cases of such conditions emerging by age 24 amid the of this period. Prolonged correlates with increased anxiety, depression, and low persisting into later years, often stemming from overprotective and reduced exposure to adult responsibilities. Individuals in this extended phase frequently encounter hurdles, including difficulties in establishing stable relationships and acquiring skills, exacerbating feelings of being "in-between" and full maturity. On a societal level, delays in labor market entry and partnership formation contribute to protracted transitions out of youthful behaviors, including slower desistance from criminal activity as fewer individuals assume adult roles that exert . These patterns underlie sharp fertility declines, with rates in countries halving over the past 60 years—from above replacement levels to averages below 1.5 children per woman by 2023—heightening risks of population shrinkage, strained pension systems, and reduced workforce growth. Emerging economies have seen even steeper drops, from 6.1 births per woman in 1960 to far lower figures today, amplifying global aging pressures and potential due to inverted dependency ratios where fewer workers support more retirees. Delayed roles also impose intergenerational burdens, such as prolonged parental financial support for adult children, which can hinder retirees' own security and slow broader societal productivity gains.

Evolutionary and Historical Context

Human Life History Theory

Human life history posits that organisms evolve to allocate finite resources—such as energy and time—among competing demands of growth, maintenance, and to maximize lifetime under prevailing environmental pressures. In , this framework explains variation in life stages across , with favoring strategies that optimize fitness in response to factors like mortality risk, resource availability, and extrinsic threats. Humans exemplify a slow life-history strategy, marked by prolonged immaturity, late age at first (typically 15–20 years in ancestral populations), fewer (averaging 4–6 lifetime), and extended extending into 's adulthood. This approach enhances survival through skill acquisition and social learning, contrasting with faster strategies in high-mortality that prioritize rapid . Central to human application is the distinction between biological maturity and full reproductive competence. signals the onset of potential fertility, with historical data from and groups indicating around ages 7–13, though effective delayed until social and somatic maturity near 15–18 years due to nutritional and experiential requirements. Adulthood emerges as the phase of net positive energy production for kin, peaking in the 30s–40s, where individuals contribute to collective fitness via provisioning and , supported by evidence from demographic studies of traditional societies showing sustained productivity beyond chimpanzees' reproductive span. Fossil records, including remains dated to 1.8 million years ago, reveal accelerated yet still extended growth patterns, underscoring evolutionary pressures for brain enlargement and cultural adaptation over hasty maturation. This K-selected orientation—emphasizing quality over quantity—arises from stable but competitive ancestral niches, where high offsets juvenile vulnerability, as quantified by comparative analyses showing humans allocate 60–70% of lifespan to pre-reproductive development versus 20–30% in other . Empirical validation includes longitudinal data from forager groups like the Hadza and Ache, where adult mortality schedules and fertility rates align with predictions of delayed and post-reproductive lifespan for grandmaternal effects. Disruptions in modern low-mortality settings can misalign developmental cues, potentially extending juvenility, yet core theory maintains that human adulthood fundamentally calibrates to environments demanding cooperative endurance and deferred gratification.

Shifts in Adulthood Onset

In pre-modern societies, the onset of adulthood was closely aligned with biological puberty and early assumption of productive roles, often occurring between ages 12 and 15. Puberty served as the primary marker, enabling reproductive capacity and integration into adult labor and family responsibilities, as evidenced in historical anthropological records of primitive and agrarian communities where children transitioned rapidly to economic contributions and marriage. This early onset reflected shorter life expectancies, limited formal education, and survival pressures that prioritized immediate maturity over extended dependency. The industrial era introduced initial shifts, extending the transition through mandatory schooling and , which decoupled biological maturity from social adulthood. By the early in Western nations, legal ages of majority stabilized around 21, but cultural milestones like completing apprenticeships or establishing households still occurred by the late teens or early 20s for most. Post-World War II economic booms further compressed the path, with U.S. data showing that by 1975, nearly 50% of individuals aged 25-34 had achieved four key markers: moving out of the parental home, marrying, securing full-time employment, and having children. Contemporary shifts, particularly since the , have markedly delayed social onset of adulthood amid prolonged , rising living costs, and labor market instability. In the U.S., the median age at first rose from 23 for men and 21 for women in 1980 to 30 and 28 by 2023, respectively. Among 21-year-olds, the proportion holding full-time jobs dropped from 52% in 1980 to 38% in 2021, while home-leaving rates declined similarly. By 2023, only 17% of 25-34-year-olds had met all five traditional milestones (adding ), down from 26% in 2005. These delays contrast with biological trends, where onset has advanced by 1-2 years over the past century due to improved , creating a divergence between physical readiness and societal role assumption. Cross-nationally, similar patterns emerge in developed economies, driven by extended higher education—40% of U.S. 25-29-year-olds held bachelor's degrees in 2023 versus 25% in 1993—and barriers to entry-level jobs. Evolutionary life-history perspectives attribute such extensions to affluent environments permitting in skills over immediate , though they note potential mismatches with ancestral patterns of quicker maturation. Economic analyses link delays to stagnant wages and housing costs, with young adults in 2023 facing 2-3 times higher burdens relative to income than in 1970.

References

  1. https://pmc.ncbi.nlm.nih.gov/articles/PMC3621648/
  2. https://www.law.cornell.edu/wex/age_of_majority
  3. https://www.parentcenterhub.org/age-of-majority/
  4. https://clbb.mgh.harvard.edu/youre-an-adult-your-brain-not-so-much/
  5. https://journeytocollege.mo.gov/when-does-the-brain-reach-maturity-its-later-than-you-think/
  6. https://www.psychologytoday.com/us/blog/deciphering-our-differences/202311/what-makes-an-adult
  7. https://health.oregonstate.edu/sites/health.oregonstate.edu/files/faculty-staff/profilepubs/settersten_et_al-becoming_adult-emerging_trends.pdf
  8. https://pmc.ncbi.nlm.nih.gov/articles/PMC5382900/
  9. https://flexbooks.ck12.org/cbook/ck-12-biology-flexbook-2.0/section/13.5/primary/lesson/growth-and-development-of-bones-bio/
  10. https://www.sciencedirect.com/science/article/pii/S2665910720301146
  11. https://pmc.ncbi.nlm.nih.gov/articles/PMC11122822/
  12. https://pmc.ncbi.nlm.nih.gov/articles/PMC3312969/
  13. https://pubmed.ncbi.nlm.nih.gov/29582267/
  14. https://rmanetwork.com/blog/what-are-my-odds-of-getting-pregnant-at-any-age/
  15. https://www.healthline.com/health/fertility-timeline
  16. https://www.bumc.bu.edu/camed/2013/07/02/fertility-peaks-around-age-30-for-both-males-and-females-boston-university-study-finds/
  17. https://www.preludefertility.com/blog/the-biological-clock-understanding-how-age-impacts-fertility
  18. https://pmc.ncbi.nlm.nih.gov/articles/PMC2892678/
  19. https://pmc.ncbi.nlm.nih.gov/articles/PMC3982854/
  20. https://pmc.ncbi.nlm.nih.gov/articles/PMC6659986/
  21. https://pmc.ncbi.nlm.nih.gov/articles/PMC5096655/
  22. https://www.sciencedirect.com/science/article/pii/S1878929315000717
  23. https://psycnet.apa.org/fulltext/2012-21989-001.html?sr=1
  24. https://www.sciencedirect.com/science/article/pii/S0149763418307905
  25. https://pmc.ncbi.nlm.nih.gov/articles/PMC7826388/
  26. https://pmc.ncbi.nlm.nih.gov/articles/PMC2396566/
  27. https://pmc.ncbi.nlm.nih.gov/articles/PMC4517225/
  28. https://journals.copmadrid.org/pi/art/pi2019a1
  29. https://jneurodevdisorders.biomedcentral.com/articles/10.1186/s11689-020-09337-y
  30. https://www.researchgate.net/publication/301486690_A_meta-analysis_update_on_the_effectiveness_of_early_self-control_improvement_programs_to_improve_self-control_and_reduce_delinquency
  31. https://www.simplypsychology.org/prefrontal-cortex-development-age.html
  32. https://pmc.ncbi.nlm.nih.gov/articles/PMC4671080/
  33. https://pmc.ncbi.nlm.nih.gov/articles/PMC11247355/
  34. https://publications.aap.org/pediatrics/article/146/Supplement_1/S18/34490/Adolescent-Brain-Development-and-Medical-Decision
  35. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0255102
  36. https://psycnet.apa.org/record/2014-45086-001
  37. https://pmc.ncbi.nlm.nih.gov/articles/PMC3445337/
  38. https://www.mdpi.com/2673-7051/4/2/15
  39. https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2011.00072/full
  40. https://www.upcounsel.com/legal-def-age-of-majority
  41. https://scholarship.law.wm.edu/cgi/viewcontent.cgi?article=2863&context=facpubs
  42. https://calawyers.org/wp-content/uploads/2021/07/When-You-Turn-18-A-Legal-Survival-Guide.pdf
  43. https://worldpopulationreview.com/country-rankings/age-of-majority-by-country
  44. https://webfs.oecd.org/els-com/Family_Database/PF_1_8_Age_threshold_Childhood_to_Adulthood.pdf
  45. https://worldpopulationreview.com/state-rankings/age-of-majority-by-state
  46. https://www.ohchr.org/en/instruments-mechanisms/instruments/convention-rights-child
  47. https://www.upcounsel.com/minors-and-contracts
  48. https://scholarship.law.tamu.edu/facscholar/1094/
  49. https://rvcc.pressbooks.pub/businesslaw131interactive/chapter/8-2-minors-or-infants/
  50. https://www.nolo.com/legal-encyclopedia/lack-capacity-to-contract-32647.html
  51. https://www.law.cornell.edu/wex/incompetency
  52. https://journalofethics.ama-assn.org/article/mental-capacity-and-contracts/2008-03
  53. https://publications.aap.org/pediatrics/article/131/4/786/31933/The-Legal-Authority-of-Mature-Minors-to-Consent-to
  54. https://www.merckmanuals.com/home/fundamentals/legal-and-ethical-issues/capacity-to-make-health-care-decisions
  55. https://epi.dph.ncdhhs.gov/cd/lhds/manuals/cd/conference/legal_2012/consent_to_treatment.pdf
  56. https://worldpopulationreview.com/country-rankings/age-of-consent-by-country
  57. https://www.worldatlas.com/society/age-of-consent-around-the-world.html
  58. https://pmc.ncbi.nlm.nih.gov/articles/PMC9212194/
  59. https://www.unicef.org/lac/media/40681/file/Legal-minimun-ages.pdf
  60. https://www.representingchildhood.pitt.edu/medieval_child.htm
  61. https://pmc.ncbi.nlm.nih.gov/articles/PMC2312095/
  62. https://www.globalcitizen.org/en/content/13-amazing-coming-of-age-traditions-from-around-th/
  63. https://helpfulprofessor.com/rite-of-passage-examples/
  64. https://www.tandfonline.com/doi/abs/10.1080/10888691.2014.954451
  65. https://journals.sagepub.com/doi/full/10.1177/2167696815613000
  66. https://www.ncbi.nlm.nih.gov/books/NBK543712/
  67. https://psycnet.apa.org/record/2015-46837-002
  68. https://www.census.gov/library/stories/2025/08/milestones-to-adulthood.html
  69. https://www.pewresearch.org/short-reads/2023/05/23/young-adults-in-the-u-s-are-reaching-key-life-milestones-later-than-in-the-past/
  70. https://www.pewresearch.org/social-trends/2019/10/23/majority-of-americans-say-parents-are-doing-too-much-for-their-young-adult-children/
  71. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1728-4457.2012.00529.x
  72. https://www.facebook.com/europeanparliament/posts/young-europeans-leave-their-parents-home-on-average-at-the-age-of-26-however-thi/1124115075746052/
  73. https://obamawhitehouse.archives.gov/sites/default/files/docs/millennials_report.pdf
  74. https://files.eric.ed.gov/fulltext/EJ883082.pdf
  75. https://www.brookings.edu/articles/the-decisive-decade-understanding-the-trajectories-of-14-to-24-year-olds/
  76. https://pmc.ncbi.nlm.nih.gov/articles/PMC11025884/
  77. https://www2.census.gov/library/working-papers/2025/demo/sehsd-wp2025-03.pdf
  78. https://www.pewresearch.org/social-trends/2014/07/17/young-adults-driving-growth-in-multi-generational-living/
  79. https://www.researchgate.net/publication/234025210_Trends_in_the_Economic_Independence_of_Young_Adults_in_the_United_States_1973-2007
  80. https://health.clevelandclinic.org/best-age-to-get-pregnant
  81. https://pathfertility.com/age-affects-male-and-female-fertility/
  82. https://www.ncbi.nlm.nih.gov/books/NBK576440/
  83. https://www.bgsu.edu/ncfmr/resources/data/family-profiles/FP-25-09.html
  84. https://ourworldindata.org/fertility-rate
  85. https://pmc.ncbi.nlm.nih.gov/articles/PMC7907839/
  86. https://ifs.org.uk/inequality/wp-content/uploads/2022/06/IFS-Deaton-Review-The-Role-Of-Parenting-In-Child-Development-1.pdf
  87. https://www.pewresearch.org/social-trends/2023/01/24/gender-and-parenting/
  88. https://usafacts.org/articles/state-relationships-marriages-and-living-alone-us/
  89. https://www.smdailyjournal.com/opinion/columnists/prolonged-adolescence/article_09bea3c8-7fe6-499e-b1a9-5665c07332b5.html
  90. https://www.denverwellnesscounseling.com/blog/extended-adolescence-the-new-normal-for-young-adults
  91. https://www.psychologytoday.com/us/blog/the-age-of-overindulgence/202104/the-big-challenge-jumping-from-adolescence-into-adulthood
  92. https://pmc.ncbi.nlm.nih.gov/articles/PMC2714655/
  93. https://www.oecd.org/en/about/news/press-releases/2024/06/declining-fertility-rates-put-prosperity-of-future-generations-at-risk.html
  94. https://www.census.gov/library/stories/2022/04/fertility-rates-declined-for-younger-women-increased-for-older-women.html
  95. https://www.mckinsey.com/mgi/our-research/dependency-and-depopulation-confronting-the-consequences-of-a-new-demographic-reality
  96. https://www.macfound.org/programs/pastwork/research-networks/research-network-on-transitions-to-adulthood
  97. https://www.nature.com/scitable/knowledge/library/life-history-evolution-68245673/
  98. https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0490
  99. https://pmc.ncbi.nlm.nih.gov/articles/PMC7293149/
  100. https://academic.oup.com/book/5825/chapter/149049110
  101. https://www.southampton.ac.uk/news/2005/11/evolution-explains-age-of-puberty.page
  102. https://www.ncbi.nlm.nih.gov/books/NBK100413/
  103. https://www.science.org/content/article/why-do-humans-mature-so-slowly-ancient-youth-offers-clues
  104. https://pmc.ncbi.nlm.nih.gov/articles/PMC10481054/
  105. https://gurven.anth.ucsb.edu/sites/secure.lsit.ucsb.edu.anth.d7_gurven/files/sitefiles/papers/kaplanetal_ch3.pdf
  106. https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2019.00918/full
  107. https://oxfordre.com/psychology/display/10.1093/acrefore/9780190236557.001.0001/acrefore-9780190236557-e-607
  108. https://www.pewresearch.org/social-trends/2024/01/25/key-milestones-for-young-adults-today-versus-30-years-ago/
  109. https://www.sciencedirect.com/science/article/pii/S1569490925000346
  110. https://pmc.ncbi.nlm.nih.gov/articles/PMC6970937/
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