adolescent psychology chapter 1

what marks transition from childhood to adulthood

puberty

Height & weight increase (growth spurt).

Rapid growth

Gonadal development (testes, ovaries).

primary sex characteristics

Secondary sex characteristics

Changes in body hair, genitals, breasts.

Brain development

Hormonal changes impact brain anatomy & function.

Endocrine System

Produces & regulates hormones.

Pituitary gland

Controls hormone levels.

Hypothalamus

Regulates the pituitary gland.

Gonadotropin-releasing hormone (GnRH) neurons are

• Activated by pubertal hormones

The HPG Axis (Hypothalamus-Pituitary-Gonad Axis) is

• Active at birth but dormant until puberty.

  • Reactivated by genetics, environment, and kisspeptin (regulated by leptin & melatonin).

Prenatal Hormones

Organize brain structures, influence behavior later.

Pubertal Hormones

Activate behaviors set in place by prenatal hormones.

Puberty & Stress

Increases cortisol levels, making adolescents more stress-sensitive.

girls start what 2 year earlier than boys

adolescent growth spurt

growth sequence

Extremities → Arms/legs → Torso/shoulders

boys have

more muscle development

girls have

Higher fat accumulation → Can lead to body dissatisfaction.

males sexual maturation

Testes, pubic hair, penis growth, voice deepening.

girls sexual maturation

Breast development, menarche (first period), pubic hair.

typical onset and duration of puberty for girls

8–13 years old, lasts 1.5–6 years.

typical onset and duration for boys

9–14 years old, lasts 2–5 years.

genetics

primary determinant

Environment

Nutrition, health, stress, family dynamics.

Secular Trend:

Puberty is starting earlier due to better nutrition/health.

what intensifies social stressors

hormones

Early Maturing Boys:

Initially popular, later higher risks (substance use, delinquency).

Late Maturing Boys

Initial struggles, but often develop resilience.

Early Maturing Girls:

Higher risks for depression, substance abuse, social anxiety.

Maturational Deviance Hypothesis

Being "different" causes distress.

Developmental Readiness Hypothesis

Younger adolescents less prepared.

Cultural Body Ideals

• Early puberty moves girls away from thinness ideal.

Why Early Maturation is Harder for Girls

maturational deviance

developmental readiness

cultural body ideals

Delayed Phase Preference

• Teens sleep/wake later due to melatonin shifts.

Consequences of Poor Sleep

Increased stress, mood issues, academic problems.

when are teen most alert

in afternoon

when are teens least alert

in the early morning

Body Image Concerns are more common in

girls and can lead to disordered eating

Anorexia Nervosa:

Restrictive eating leading to dangerously low body weight.

Bulimia Nervosa

Binge-eating followed by purging (vomiting, laxatives).

Binge-Eating Disorder (BED)

• Binging without purging; associated with obesity.