1. Pubertal Processes
What biological changes of puberty have the biggest impact on boys or girls?
What teens worry about?
What teens talk about?
What teens feel proud of?
What teens feel ashamed of?

2. What is Puberty?
Period of physical growth leading to attainment of reproductive capability
Five areas of changes:
Acceleration then deceleration of skeletal growth
Changes in body composition & distribution of fat and muscle
Development of circulatory and respiratory systems, increased endurance
Maturation of reproductive organs, secondary sex characteristics
Changes in nervous and endocrine systems

3. Influences on Pubertal Timing
Largely genetic
Influenced by nutrition and medical health
Level of body fat
Stress

4. What Changes at Puberty: Levels of Sex Hormones
Endocrine system produces, circulates, and regulates the level of sex hormones:
Releasing Factors
Pituitary
Gland
Hypothalamus
LH & FSH
Androgens
and
Estrogens
Monitoring
Levels
Sex
Organs
Sex hormones

5. What Changes: Physical Growth
Hypothalamus
Pituitary Gland
Growth
Hormones
Thyroid
Sex Organs
These hormones
stimulate physical
growth
Thyroid Hormones
Androgens

6. Changes in Muscle and Fat
Before puberty, boys = girls on levels of muscle and fat
Both boys and girls develop muscle and increase fat during puberty
Muscle grows faster in boys, fat increases faster in girls
End of puberty muscle/fat ratio: 3:1 for boys, 5:4 for girls

7. Change in body fat (kg)

8. Physical Changes in Adolescent Brains may Account for Turbulent Teen Years, McLean Hospital study reveals
June 11, Belmont, MA-- Parents of teenagers can take heart in a McLean Hospital study that provides the first real look at the physiological basis for emotional and cognitive development during adolescence.
In this study, scientists used functional magnetic resonance imaging (fMRI) to compare the emotional processing of healthy 10- to 18-year-olds with that of normal adults. The researchers focused on the level of brain activity in the amygdala, a region that guides instinctual or "gut" reactions, and the frontal lobe, the seat of rationalization and reasoning. They found that when young adolescents process emotion, the level of brain activity in the amygdala is higher than the activity in the frontal lobe. However, as adolescents progress into adulthood, there is an age-related shift: activation in the amygdala decreases while activity in the frontal lobe increases. Adults show greater overall activation in the frontal lobe and less activation in the amygdala as compared with adolescents.
Brain Development

9. Brain Development, c’t’d
"These results suggest that adolescents are more prone to react with ‘gut instinct’ when they process emotions, but as they mature into early adulthood, they are able to temper their instinctive ‘gut reaction’ response with rational, reasoned responses," says Yurgelun-Todd. "Adult brains use the frontal lobe to rationalize or apply brakes to emotional responses. Adolescent brains are just beginning to develop that ability."
Results from this phase of the study revealed a similar shift in functional activation for language based tasks during adolescence. Data collected from the study indicated that as subjects aged, the activation in the temporal region decreased while activity in the frontal lobe increased, indicating that the reasoning/rationalization part of the brain becomes increasingly involved in the center for language production as individuals mature.

10. Tanner Stages
Most widely used way of measuring pubertal status (Marshall & Tanner, 1969)
Five stages of penis/scrotum and pubic hair development for boys; Five stages of breast and pubic hair development for girls.
Developed the system by assessing nude photographs of adolescent boys and girls
Unclothed adolescents are assessed by trained health professionals, with physical exam and photographs
Less intrusive alternative: teens look at photos indicating Tanner stages, and rate themselves.

11. Appearance of Primary and Secondary Sex Characteristics

12. Puberty and Self-Esteem
Does self-esteem drop?
Girls: Puberty associated with small decrease in self-esteem
Greatest impact is on girls experiencing multiple transitions at once (e.g., menarche, dating, school change)

13. Puberty and Moodiness Does puberty increase moodiness? Maybe.
Boys: high testosterone associated with rebelliousness, aggression, sadness (Sussman)
Boys: rapid increase in testosterone associated with better adjustment (Sussman)
Girls: Rapid increases in estrogen associated with depression, but interpersonal stress has a bigger influence on mood than does hormonal level (Brooks-Gunn).
“Beeper studies” find evidence of moodiness, but moods change with activities, not randomly.

14. Puberty and Family Relationships
Increased distance and conflict, especially conflict with mother
Conflict gradually diminishes after the growth spurt
Possible explanations:
Evolutionary process to achieve separation
Change in established childhood relationship patterns, a transition for all family members
Some variation by culture

15. Reactions to Sexual Development
Girls are often ambivalent about menarche
Prior expectations affect girls’ experience of menarche
Boys do not tend to feel anxious or embarrassed about first ejaculation
However, boys do not talk about it with anyone

16. Early vs. Late Maturation: Girls
Girls: Early maturation associated with more psychological problems
Poorer body image, more food intake restriction
Higher rates of depression, anxiety disorders
Higher rates of delinquency, substance abuse (especially if pre-existing problems), early sexual intercourse
But, more popular, especially with boys

17. Early vs. Late Maturation: Boys
Early maturation associated with better social and emotional functioning
Good to be taller and stronger than one’s peers
Associated with popularity, and more opportunity for contact with girls
More likely to be leaders, more self-confidence
But there are some down sides:
more at risk for antisocial behavior, substance abuse
At the time of puberty, late maturers are more intellectually curious, less prone to intense negative emotion

18. Why Does Early- vs. Late Pubertal Timing Matter?
Deviancy hypothesis (Peterson & Taylor, 1980): Both early and late maturers at risk, because development is not in sync with that of peers.
Stage termination hypothesis (Peskin & Levin, 1972): early maturation (not late maturation) is bad because it interrupts normal course of development.

19. Puberty and Body Image in Girls
Overall, girls are less satisfied with their weight as they become pubertal.
Height, weight, overall appearance: in some studies, early developers are (by the time they reach late adolescence) less satisfied than on-time or late-developers, who were most satisfied.

20. Pubertal Timing and Girls’ Body Image
6th
7th
8th
12th

21. Puberty and Body Image in Boys
Early maturing boys more satisfied than on-time or late boys with their height, weight, body build
But, the advantages for early maturers do not persist across adolescence

22. Pubertal Timing and Body Image in Boys
6th
7th
8th
12th