Adult

An adult is an animal that has reached full growth. The biological definition of the word means an animal reaching sexual maturity and thus capable of reproduction. In the human context, the term adult has meanings associated with social and legal 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 legal adulthood is 18 although definition may vary by legal rights, country, and psychological development.

Adult moths and butterflies are easily distinguished from their caterpillars.

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

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). 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. 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. Adulthood, in more recent years, as it has been studied has developed a characteristic list, that goes far beyond just ones physical maturity. 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". 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.

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. Girls generally complete puberty by 15–17, and boys by age 16 or 17. Nutrition, genetics and environment also usually play a part in the onset of puberty. 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.

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.

Legal adulthood

Legally, adulthood typically means that one has reached the age of majority – when parents lose parental rights and responsibilities regarding the person concerned. 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.

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);
2. The legal age of adulthood in Nebraska and Alabama in the United States is 19.
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. 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"

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.)

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.

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. 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.

As of December 2019^[update], the federal government raised the legal age to purchase tobacco and vaping products from 18 to 21. 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.

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.

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 where there are ongoing debates about whether those between 18 and 20 should be exempted from the death penalty.

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.

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. 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.

At the same time, however, even though the generally accepted age of majority is 18 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.

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

In contrast to biological perspectives of aging and adulthood, social scientists conceptualize adulthood as socially constructed. 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.

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. 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.

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. The criteria are marked by a growing "importance of individualistic criteria and the irrelevance of the demographic markers of normative conceptions of adulthood." In particular, younger cohorts' attainment of adulthood centers on three criteria: gaining a sense of responsibility, independent decision-making, and financial independence.

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. 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. Arnett makes it clear that these 5 aspects of emerging adulthood are only relevant during the life stage of emerging adulthood.

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". These individuals believe they have a good chance of turning out better than their parents did.

Religion

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; 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". 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. 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.

See also

• Adultism
• Overparenting
• Manhood
• Womanhood

References

1. "Adult organism". Archived from the original on 2022-11-05. Retrieved 2022-11-05.
2. McNamara, Thomas Edward (2004). Evolution, Culture, and Consciousness: The Discovery of the Preconscious Mind. University Press of America. pp. 262–263. ISBN 0-7618-2765-X. Retrieved December 11, 2018.
3. SETTERSTEN, RICHARD (2015). "Becoming adult: Meanings of markers to adulthood" (PDF). Emerging Trends in the Social and Behavioral Sciences: An Interdisciplinary, Searchable, and Linkable Resource: 1–16 – via umnikizdes.
4. Marantz Henig, Robin (2010-08-18). "What Is It About 20-Somethings?". The New York Times. p. 10. Archived from the original on 2011-05-11. Retrieved 2010-09-24. The Discovery of adolescence is generally dated to 1904, with the publication of the massive study "Adolescence," by G. Stanley Hall, a prominent psychologist and first president of the American Psychological Association.
5. "Has Fecundability been Declining in Recent Years in Developed Countries?". Journal of Biosocial Science. 15 (1). January 1983. doi:10.1017/s0021932000006349. ISSN 0021-9320.
6. Becker; Landau, Sidney I., eds. (1986). International dictionary of medicine and biology. Wiley. ISBN 0-471-01849-X. OCLC 801872498.
7. Churchill's illustrated medical dictionary. New York: Churchill Livingstone. 1989. ISBN 0-443-08691-5. OCLC 19322374.
8. Gluckman, Peter D.; Hanson, Mark A. (January 2006). "Evolution, development and timing of puberty". Trends in Endocrinology & Metabolism. 17 (1): 7–12. doi:10.1016/j.tem.2005.11.006. PMID 16311040. S2CID 26141301.
9. Kail, RV; Cavanaugh JC (2010). Human Development: A Lifespan View (5th ed.). Cengage Learning. p. 296. ISBN 978-0-495-60037-4. Archived from the original on 2023-01-10. Retrieved 2018-03-20.
10. Schuiling, Kerri Durnell; Likis, Frances E. (2016). Women's Gynecologic Health. Jones & Bartlett Learning. p. 22. ISBN 978-1-284-12501-6. Archived from the original on January 10, 2023. Retrieved March 20, 2018. The changes that occur during puberty usually happen in an ordered sequence, beginning with thelarche (breast development) at around age 10 or 11, followed by adrenarche (growth of pubic hair due to androgen stimulation), peak height velocity, and finally menarche (the onset of menses), which usually occurs around age 12 or 13.
11. Phillips, D. C. (2014). Encyclopedia of Educational Theory and Philosophy. SAGE Publications. pp. 18–19. ISBN 978-1-4833-6475-9. Archived from the original on January 10, 2023. Retrieved March 20, 2018. On average, the onset of puberty is about 18 months earlier for girls (usually starting around the age of 10 or 11 and lasting until they are 15 to 17) than for boys (who usually begin puberty at about the age of 11 to 12 and complete it by the age of 16 to 17, on average).
12. Solomon, Jean W.; O'Brien, Jane Clifford (2014). Pediatric Skills for Occupational Therapy Assistants – E-Book. Elsevier Health Sciences. p. 103. ISBN 978-0-323-29163-7. Retrieved March 20, 2018.
13. Ge, Xiaojia; Natsuaki, Misaki N.; Neiderhiser, Jenae M.; Reiss, David (2007). "Genetic and Environmental Influences on Pubertal Timing: Results From Two National Sibling Studies". Journal of Research on Adolescence. 17 (4): 767–788. doi:10.1111/j.1532-7795.2007.00546.x.
14. "Stages of puberty: what happens to boys and girls". nhs.uk. 2018-04-26. Archived from the original on 2020-12-04. Retrieved 2020-12-13.
15. Henig, Robin Marantz (18 August 2010). "What is It About 20-Somethings?". The New York Times. Archived from the original on 26 February 2017. Retrieved 23 February 2017.
16. Petanjek, Zdravko; Judaš, Miloš; Šimić, Goran; Rašin, Mladen Roko; Uylings, Harry B. M.; Rakic, Pasko; Kostović, Ivica (2011). "Extraordinary neoteny of synaptic spines in the human prefrontal cortex". Proceedings of the National Academy of Sciences. 108 (32): 13281–13286. Bibcode:2011PNAS..10813281P. doi:10.1073/pnas.1105108108. PMC 3156171. PMID 21788513.
17. "People don't become 'adults' until their 30s, say scientists". BBC News. 19 March 2019. Archived from the original on 14 June 2022. Retrieved 14 June 2022.
18. Romer, Daniel (2010). "Adolescent risk taking, impulsivity, and brain development: implications for prevention". Developmental Psychobiology. 52 (3): 263–276. doi:10.1002/dev.20442. PMC 3445337. PMID 20175097.
19. Casey, BJ; Caudle, Kristina (2013). "The Teenage Brain: Self Control". Current Directions in Psychological Science. 22 (2): 82–87. doi:10.1177/0963721413480170. PMC 4182916. PMID 25284961.
20. Epstein, Robert (2007-06-01). "The Myth of the Teen Brain". Scientific American. Archived from the original on 2021-12-13. Retrieved 2021-12-07.
21. Moshman, David (2011). Adolescent Rationality and Development. Psychology Press. doi:10.4324/9780203835111. ISBN 978-0-203-83511-1. Archived from the original on 2021-12-07. Retrieved 2021-12-07.
22. Hamilton, Vivian (2016). Adulthood in Law and Culture. College of William & Mary Law School: Faculty Publications. pp. 55–97.
23. Spooner, Samantha (July 14, 2014). "Legal ages of marriage across Africa: Even when it's 18, they are married off at 12!". Mail & Guardian Africa. Archived from the original on January 24, 2018.
24. Bellemare, Steven (July 2008). "Age of consent for sexual activity in Canada". Paediatrics & Child Health. 13 (6): 475. doi:10.1093/pch/13.6.475. PMC 2532909. PMID 19436429.
25. B. A., Political Science. "What Does Age of Majority Mean in Canada?". ThoughtCo. Archived from the original on 2021-01-08. Retrieved 2020-12-13.
26. "Age of Majority by State as of 2020". Policygenius. Archived from the original on 2020-12-07. Retrieved 2020-12-13.
27. Birnbaum, Gemma R. (28 October 2020). ""Old Enough to Fight, Old Enough to Vote": The WWII Roots of the 26th Amendment". Archived from the original on 2021-06-13. Retrieved 2021-06-13.
28. "Statute 82 Page 1213-2 PDF file" (PDF). Archived (PDF) from the original on 2021-05-15. Retrieved 2021-06-13.^{[full citation needed]}
29. "The 1984 National Minimum Drinking Age Act | APIS - Alcohol Policy Information System". alcoholpolicy.niaaa.nih.gov. Archived from the original on 2021-06-13. Retrieved 2021-06-13.
30. DeMatteo, Megan (22 July 2020). "My first unsecured credit card came with a $20,000 limit—here's why that is rare today". CNBC. Archived from the original on 13 June 2021. Retrieved 13 June 2021.
31. "Young Adults and the Affordable Care Act: Protecting Young Adults and Eliminating Burdens on Families and Businesses | CMS". Archived from the original on 2021-06-13. Retrieved 2021-06-13.
32. "Tobacco 21". FDA. 22 February 2021. Archived from the original on 22 June 2021. Retrieved 13 June 2021.
33. "What is the Age Limit of Medical Cannabis in California?". 18 September 2018. Archived from the original on 13 June 2021. Retrieved 13 June 2021.
34. Lindeman, Tracey (30 October 2019). "Quebec raises legal consumption age for cannabis to 21". The Guardian. Archived from the original on 24 May 2021. Retrieved 13 June 2021.
35. "Mandatory life without parole prohibited for young WA adults". 11 March 2021. Archived from the original on 13 June 2021. Retrieved 13 June 2021.
36. Michaels, Andrew (9 June 2016). "A Decent Proposal: Exempting Eighteen- to Twenty-Year-Olds from the Death Penalty". Archived from the original on 13 June 2021. Retrieved 13 June 2021.
37. "Kentucky Trial Judge Rules Death Penalty Unconstitutional for Offenders Younger Than Age 21". Archived from the original on 2021-06-13. Retrieved 2021-06-13.
38. "Should 18- to 21-year-olds be eligible for execution?". 19 September 2019. Archived from the original on 2021-06-13. Retrieved 2021-06-13.
39. "Texas bill aims to crack down on human trafficking". 29 April 2021. Archived from the original on 13 June 2021. Retrieved 13 June 2021.
40. "Raise age for sale of cigarettes to 21 and stop 'tobacco epidemic', say UK MPS". The Guardian. 9 June 2021. Archived from the original on 13 June 2021. Retrieved 13 June 2021.
41. Arain, Mariam; Haque, Maliha; Johal, Lina; Mathur, Puja; Nel, Wynand; Rais, Afsha; Sandhu, Ranbir; Sharma, Sushil (2013). "Maturation of the adolescent brain". Neuropsychiatric Disease and Treatment. 9: 449–461. doi:10.2147/NDT.S39776. PMC 3621648. PMID 23579318.
42. "age of majority". LII / Legal Information Institute. Retrieved 2023-11-03.
43. Niel, Clara (October 2020). "Takoma Park is one of five cities where minors can vote. And young voters are turning out". Archived from the original on 2021-05-10. Retrieved 2021-06-13.
44. Settersten, Richard A. Jr. (2 December 2018). Lives in time and place: the problems and promises of developmental science. Taylor & Francis. ISBN 978-0-415-78421-4. OCLC 1121019775.^{[page needed]}
45. Elder, Glen H., ed. (1985). "Perspectives on the life course". Life course dynamics: trajectories and transitions, 1968-1980. Cornell University Press. pp. 23–49. ISBN 0-8014-9323-4. OCLC 469306035.
46. Ryff, Carol D. (16 January 2018). "The Subjective Experience of Life-Span Transitions". In Rossi, Alice S. (ed.). Gender and the life course. Routledge. pp. 97–113. ISBN 978-1-351-32902-6. OCLC 1028167964.
47. Arnett, Jeffrey Jensen (1998). "Learning to Stand Alone: The Contemporary American Transition to Adulthood in Cultural and Historical Context". Human Development. 41 (5/6): 295–315. doi:10.1159/000022591. JSTOR 26763368. S2CID 143862036.
48. Levinson, Daniel J. (1979). The Seasons of a man's life. Ballantine Books. ISBN 0-345-29727-X. OCLC 9162079.
49. Shanahan, Michael J. (August 2000). "Pathways to Adulthood in Changing Societies: Variability and Mechanisms in Life Course Perspective". Annual Review of Sociology. 26 (1): 667–692. doi:10.1146/annurev.soc.26.1.667. JSTOR 223461.
50. Arnett, Jeffrey Jensen (2003). "Conceptions of the Transition to Adulthood Among Emerging Adults in American Ethnic Groups". New Directions for Child and Adolescent Development. 2003 (100): 63–76. doi:10.1002/cd.75. PMID 12955983.
51. Aronson, Pamela (February 2008). "The Markers and Meanings of Growing Up: Contemporary Young Women's Transition From Adolescence to Adulthood". Gender & Society. 22 (1): 56–82. doi:10.1177/0891243207311420. PMC 2312095. PMID 18418470.
52. Barrett, Anne E. (March 2003). "Socioeconomic Status and Age Identity: The Role of Dimensions of Health in the Subjective Construction of Age". The Journals of Gerontology Series B: Psychological Sciences and Social Sciences. 58 (2): S101 – S109. doi:10.1093/geronb/58.2.s101. PMID 12646599.
53. Barrett, Anne E. (May 2005). "Gendered experiences in midlife: Implications for age identity". Journal of Aging Studies. 19 (2): 163–183. doi:10.1016/j.jaging.2004.05.002.
54. Settersten, Richard A. Jr.; Furstenberg, Frank F.; Rumbaut, Rubén G., eds. (15 April 2008). "On the Frontier of Adulthood: Emerging Themes and New Directions". On the frontier of adulthood: theory, research, and public policy. University of Chicago Press. pp. 3–25. ISBN 978-0-226-74890-0. OCLC 191752480.
55. Shanahan, Michael J.; Porfeli, Erik J.; Mortimer, Jeylan T.; Erickson, Lance D. (15 April 2008). "Subjective Age Identity and the Transition to Adulthood: When do Adolescents Become Adults?". In Settersten, Richard A. Jr.; Furstenberg, Frank F.; Rumbaut, Rubén G. (eds.). On the frontier of adulthood: theory, research, and public policy. University of Chicago Press. pp. 225–255. ISBN 978-0-226-74890-0. OCLC 191752480.
56. Arnett, Jeffrey Jensen (2014). Emerging adulthood: the winding road from the late teens through the twenties. Oxford University Press. ISBN 978-0-19-992938-2. OCLC 945977734.^{[page needed]}
57. Waters, Mary C.; Carr, Patrick J.; Kefalas, Maria J.; Holdaway, Jennifer (15 April 2008). "Becoming Adult: Meanings and Markers for Young Americans". In Settersten, Richard A. Jr.; Furstenberg, Frank F.; Rumbaut, Rubén G. (eds.). On the frontier of adulthood: theory, research, and public policy. University of Chicago Press. pp. 169–190. ISBN 978-0-226-74890-0. OCLC 191752480.
58. "Jeffrey Jensen Arnett, PhD". apa.org. Archived from the original on 2020-11-02. Retrieved 2020-12-13.
59. Munsey, Christopher (June 2006). "Emerging adults: The in-between age". Monitor on Psychology. Vol. 37. American Psychological Association. p. 68. Retrieved 2020-12-13.
60. Arnett, Jeffrey Jensen (December 2007). "Emerging Adulthood: What Is It, and What Is It Good For?". Child Development Perspectives. 1 (2): 68–73. doi:10.1111/j.1750-8606.2007.00016.x. ISSN 1750-8592.
61. "Bar Mitzva in Peninei Halakha by rabbi Eliezer Melamed". Archived from the original on 2022-10-18. Retrieved 2022-10-18.
62. "Bat Mitzva in Peninei Halakha by rabbi Eliezer Melamed". Archived from the original on 2022-10-18. Retrieved 2022-10-18.
63. "Code of Canon Law: Table of Contents". vatican.va. Archived from the original on 2021-08-22. Retrieved 2022-12-23.
64. Donelson, Elaine (1999). "Psychology of religion and adolescents in the United States: Past to present". Journal of Adolescence. 22 (2): 187–204. doi:10.1006/jado.1999.0212. PMID 10089119.
65. Lee, Bo Hyeong Jane; Pearce, Lisa D.; Schorpp, Kristen M. (September 2017). "Religious Pathways from Adolescence to Adulthood". Journal for the Scientific Study of Religion. 56 (3): 678–689. doi:10.1111/jssr.12367. PMC 5912683. PMID 29706663.