Adolescent Psych: Chapter 3
Biological Foundations, Puberty,
and Health
Evolution and Adolescent
Development
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Natural Selection: the evolutionary
process that favors individuals of a
species that are best adapted to survive
and reproduce.
Survivors are better adapted to the
world than non-survivors.
Complete title of Darwin’s book
Evolutionary psychology
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Evolutionary psychology emphasizes
the importance of adaptation,
reproduction, and “survival of the fittest”
in explaining behavior
What behavior assists in gene
propagation and what behavior
interferes in gene propagation?
The nature of genes: Questions?
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What is a genotype?
What is a phenotypes?
What is a “reaction range”?
What is canalization?
What is behavior genetics?
How can effects of genetics be sorted
out from effects of environment?
Genotype
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A genotype is your genetic code as
determined by strands of nucleotides in
contained in phosphate-sugar ladders in
the nucleus of your cells
What are nucleotides?
What is adenine? Guanine? Cytosine?
Thymine?
Karyotype
Genotype/Karyotype
Genotype
Chromosome
Genotype
DNA
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Adenine
Thymine
Cytosine
Guanine
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Uracil in RNA
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Genotype: Purines
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Adenine
Guanine
Genotype: Pyramidines
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Thymine
Cytosine
Genotype
Making tissue from genes
Twin studies
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Monozygotic twins
Dizygotic twins
Concordance studies
Adoption studies help to separate
genetics from environmental influences
Temperament
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Easy Child: positive mood, and adapts
well
Difficult Child: react negatively and
fusses; low adaptability
Slow-to-warm child: low activity,
somewhat slow adaptability, low
intensity of mood
Heredity and Environment
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Passive genotype-environment
Evocative genotype-environment
Active niche-picking genotypeenvironment
There is an heredity-environment
correlation
Puberty
Physical Changes
Hormonal Changes
Psychological Dimensions
Puberty
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Puberty is a period of rapid physical
maturation involving hormonal and
bodily changes that occur primarily
during adolescence.
Menarche
– 106 pounds +- 3lbs
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Issues of maturation
Hormone changes
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Hormones: powerful chemical
substances secreted by the endocrine
glands and carried through the body by
the bloodstream
Hypothalamus and pituitary gland
Estrogen, progesterone, estradiol and
female development
Testosterone, androgens
Estrogens
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Estrogens are female reproductive
hormones which are secreted by the
ovaries.
They stimulate the proliferation of the
lining of the uterus during the estrous
cycle of non-primates, and the
menstrual cycle of primates (including
humans).
Hypothalamus and pituitary
glands
Estrogens
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Play a part in the estrous/menstrual
cycle
Estrogens function in maintaining
female secondary sexual
characteristics.
The most active form of endogenous (or
made in the body) estrogen is estradiol.
Estrogens
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Estrogen has beneficial effects in
preventing heart disease, osteoporosis,
and Alzheimer's disease.
However, there is also evidence that
estrogen may promote cancers of the
breast, uterus, and other organs.
Estrogens
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The way that estrogen works is to enter
the cells of its target organ, bind with a
receptor protein within the cell, which
then enters the cell nucleus and
interacts with nucleic acids to promote
the synthesis of specific proteins.
All hormones work in this same general
manner regardless of sex or type
Estrogen
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Estrogens are important chemical
signals that influence the growth and
regulation of the liver, the
cardiovascular system, and of sexual
development and function.
These molecules are steroid hormones
synthesized by cholesterol within the
female ovaries and the male testes.
Estrogen: Estradiol molecule
Estrogen
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Estrogen plays a significant role in
breast and uterine development by
encouraging DNA synthesis and cell
division.
Estrogen also aids in the development
of the male sperm production. (little
known fact)
Estrogen
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The binding of estrogen to the receptor
inside the cell or on the cell surface is
often referred to as a "lock and key fit,"
in which estrogen is the key and the
receptor is the lock.
Testosterone
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Stimulates the body's development of
muscle, bone, skin, and sex organs,
along with masculine physical features,
such as hair growth.
Recently, scientists have discovered
that testosterone also improves mental
power, by enhancing visual and
perceptual skills.
Testosterone
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In men, testosterone is produced in the
testes, by a group of cells known as
Leydig cells. These cells begin
secreting high doses of testosterone
during puberty to trigger increased lean
muscle mass, sex organ growth, bone
formation, deeper voice, and higher
energy levels.
Testosterone
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Peak testosterone levels are reached in
a man's early to mid- 20s.
Vital role testosterone plays in health
– Testosterone deficiency symptoms:
depression, fatigue, low sex drive,
irritability, loss of facial/body hair, thinning
and wrinkling of skin, weight gain, and
weakening of bone and muscle tissue
Factors affecting puberty?
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Factors affecting hormones?
Foods; estrogen in cattle
Lighting; electric lighting
Stress; busy schedules
Athletic activities
Variations in sexual development
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Early male maturers
Late male matuerers
Early female maturers
Late female maturers
Male sexual development
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Development of pubic hair
Voice changes
Increase in muscle mass
Begins as early as 10 years to as late
as 13.5 years in most boys
Ends as early as 13 years to as late as
17 years in most boys
Female sexual development
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Menarche may begin normally any time
between the ages of 9 and 15 years.
Recorded earliest onset is age 5; a girl
in Peru had a child at age 6
breast buds, emergence of pubic hair
growth in height, widening of hips
added adipose (fat) tissue
Glands involved in pubertal
changes
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Ovaries/testes
Adrenal gland
Pituitary gland
Hypothalamus
Thyroid gland
Psychological effects of pubertal
physiological changes
How boys and girls view
themselves through the changes
Body image
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Adolescents are preoccupied with their
bodies
There are gender differences in
adolescents’ perceptions of their bodies
– girls are less happy with their bodies and
have more negative body images
– boys are more happy with their bodies and
have more positive body images
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Fat vs muscle changes
Menarche and menstrual cycles
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Psychological experience of menarche
an menstruation is dependant on how it
has been introduced to girls
“The Curse” vs “You’re a woman now!”
Generally it is mildly exciting and at
worst it is considered a hassle
Girls are somewhat embarrassed about
menarche; tell mom but nobody else
Adolescent health issues
Leading cause of death in
adolescents
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Accident
Suicide
Homicide
Teenage suicide: Danger signs
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Talking about suicide, or killing oneself,
even in a joking manner.
Statements about hopelessness,
helplessness, or worthlessness.
Preoccupation with death.
Suddenly happier, calmer.
Loss of interest in things one cares
about.
Teenage suicide: Danger signs
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Visiting or calling people one cares
about.
Making arrangements; setting one's
affairs in order.
Giving things away.
Any threats should be listened to and
taken seriously; do not ignore these
signs
Further indicators of possible
teen suicide risk
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Persistent sad or "empty" mood.
Feeling hopeless, helpless, worthless,
pessimistic and or guilty.
Substance abuse.
Fatigued or loss of interest in ordinary
activities.
Disturbances in eating and sleeping
patterns. Irritability.
Columbine suicide note
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``By now, it's over. If you are reading this, my
mission is complete. Your children who have
ridiculed me, who have chosen not to accept
me, who have treated me like I am not worth
their time are dead. THEY ARE FUCKING
DEAD!, I may have taken their lives and my
own _ but it was your doing. Teachers,
parents, LET THIS MASSACRE BE ON
YOUR SHOULDERS UNTIL THE DAY YOU
DIE.''
End of Chapter 3
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Questions about chapter 3 lecture,
book, etc.?