Adolescent Psych: Chapter 3

Biological Foundations, Puberty, and Health

Evolution and Adolescent Development 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

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?

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

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

GenotypeChromosome

GenotypeDNA Adenine Thymine Cytosine Guanine

Uracil in RNA

Genotype: Purines

Adenine Guanine

Genotype: Pyramidines

Thymine Cytosine

Genotype

Making tissue from genes

Twin studies

Monozygotic twins Dizygotic twins Concordance studies Adoption studies help to separate

genetics from environmental influences

Temperament

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

Passive genotype-environment Evocative genotype-environment Active niche-picking genotype-

environment There is an heredity-environment

correlation

Puberty

Physical Changes

Hormonal Changes

Psychological Dimensions

Puberty

Puberty is a period of rapid physical maturation involving hormonal and bodily changes that occur primarily during adolescence.

Menarche– 106 pounds +- 3lbs

Issues of maturation

Hormone changes

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

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

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

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

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

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

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

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

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

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

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?

Factors affecting hormones? Foods; estrogen in cattle Lighting; electric lighting Stress; busy schedules Athletic activities

Variations in sexual development

Early male maturers Late male matuerers Early female maturers Late female maturers

Male sexual development

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

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 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

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 Fat vs muscle changes

Menarche and menstrual cycles

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 Accident Suicide Homicide

Teenage suicide: Danger signs

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

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 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

``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

Questions about chapter 3 lecture, book, etc.?