PSY 101   
                Images] Development 3: Adolescence & Adulthood


1. Physical Changes of Adolescence

Puberty: the maturation of sexual functions
  • Males: between 11 and 16 years old
  • Females: between 10 and 15 years old
  • Early maturation in girls and late maturation in boys is associated with self-consciousness about looks
  • Early maturation in both girls & boys is associated with increased alcohol/drug use, risky behaviors, and trouble with law
  • Early maturing girls do more poorly academically; have earlier intercourse, higher risk for eating disorders
  • Males: penis, testes
    • Sperm produced in US males ca. 14 years old
  • Females: ovaries, vagina, uterus
    • Onset of menstruation in females = menarche (in US ca. 12.5 years old
Grey vs. white matter

3. Identity Development in Late Adolescence

[James_Marcia]Even though Erik Erikson argued for Identity vs. Role Confusion as the main struggle of adolescents, here is a more elaborate and contemporary version. It was developed by the Canadian psychologist, James E. Marcia, and describes late adolescents (roughly ages 16-22).

Are there people or characters in the media (TV, movies, etc.) who seem like they fulfill any of these four types of identity development?

Identity Achievement Know what they want to do and have or are taking steps to do it

Identity Foreclosure

Know what they want to do and have for a long time because they are going to do what others like their parents have told them what to do


Don't know right now exactly what they will be doing, but are continuing their education or otherwise doing something temporarily until they can commit themselves to further training and/or action


Don't know what they want or will be doing in the future, don't care that they don't know, and are doing nothing to remedy the absence of any future direction

The concept of the "Adult Transition" or "Emerging Adulthood" as a distinct period in Western culture has begun to get more and more attention in the last decade (see Arnett, 2014; Arnett et al. 2014).

Average age of first marriageCharacteristics of this period include

Identity exploration: Individuals are exploring and trying out different solutions in both their work settings and love relationships. Career pathways are generally given greater priority than getting married. The average age of marriage is increasing. Now in the late 20s.
Sense of instability (the flip side of explorations) in both love and work. Multiple changes in jobs (median number of jobs in decade after high school graduation is 8). Lack of certitude is often reflected in the affective responses of emerging adults, e.g., 60% of people in their 20s describe themselves as "anxious" and 40% as "depressed" from time to time (Arnett et al, 2014).
Focus upon the self: for many this is the period with the lowest number of social roles and commitments.
Feeling "in between" adolescence and full adulthood (not still adolescent, not yet adult)
Possibilities & Optimism: Despite the "Great Recession" of 2008, research in the early 2010s shows a strikingly high positive outlook in this age group.

[Development Timetable - Adults]


Seasons of A Man's Life1. Is there such a thing as a mid-life crisis among adults?

2. Life Transitions in Adulthood
Family of 12

3. Aging

Arnett, J. J. (2014). Emerging Adulthood: The Winding Road from the Late Teens through the Twenties (2nd ed.). New York, NY: Oxford University Press.

Arnett, J. J., Žukauskienė, R., & Sugimura, K. (2014). The New Life State of Emerging Adulthood at Ages 18-29 Years: Implications for Mental Health. Lancet Psychiatry, 1, 569-576.

Marcia, J. E., (1966). Development and validation of ego identity status. Journal of Personality and Social Psychology, 3, 551-558.


This page was originally posted on 10/10/03 and last updated on October 14, 2016