Developmental Psychology: Unit 3 (The evolutionary perspective)

Natural Selection

process by which species that are best adapted survive and reproduce.

Evolutionary Psychology

importance of adaptation, reproduction and“survival of the fittest" in shaping the behavior in an individual.

Adaptation

species becomes fitted to its environment through survival by means of its physical and behavioral characteristic.

Reproduction

production of an offspring

Survival of the fittest

any organism that best adjusted to its environment and as most likely to survive and reproduce

3 Components of Evolutionary Psychology

Adaptation, Reproduction and Survival of the fittest

FERTILIZATION (Conception)

sperm and ovum—the male and female gametes, or sex cells—combine to create a single cell called a zygote, which duplicates itself again and again by cell division to produce all the cells that make up a baby.

sperm and ovum

the male and female gametes/sex cell.

Zygote

One-celled organism resulting from fertilization.

Fertile Window

Time during which conception is possible. Highly unpredictable.

Artificial Insemination -

Sperm is injected into a woman’s vagina, cervix, or uterus

In Vitro Fertilization (IVF) -

woman's ova are surgically removed, fertilized in a laboratory dish, and implanted in the woman’s uterus.

Cryopreservation (Egg Freezing)

Eggs are harvested with the intention of conceiving a child at a later date with the help of IVF.

To extend the years of a woman’s fertility

Dizygotic Twins (Fraternal Twins)

Result of two separate eggs being fertilized by two different sperm to form two unique individuals.

Monozygotic Twins (Identical Twins)

Result from the cleaving of one fertilized egg and are generally genetically identical.

Deoxyribonucleic Acid (DNA)

Chemical that carries inherited instructions for the development of all cellular forms of life.

bases

dna 4 chemical units

4 bases

o A – adenine

o T – thymine

o C – cytosine

o G – guanine

Chromosomes

Coils of DNA that consist of smaller segments called genes.

Genes

Small segments of DNA located in definite positions on particular chromosomes. Functional units of heredity.

Human Genome

complete sequence of genes in the human body.

Mutations

Permanent alterations in genes or chromosomes that may produce harmful characteristics.

Autosomes

22 pairs of chromosomes not related to sexual expression.

Sex Chromosomes

23rd pair of chromosomes that determines sex of the baby.

Male Sex Chromosomes

XY CHROMOSOME

Female Sex Chromosomes

XX CHROMOSOMES

Alleles

• Genes that can produce alternative expressions of a characteristic.

• Every person receives one maternal and one paternal allele for any given trait.

Homozygous

When both alleles from the parents are the same.

Heterozygous

When both alleles from the parents are the same.

Phenotype

Observable characteristics of a person.

Genotype

Genetic makeup of a person, containing both expressed and unexpressed characteristics.

Alpha thalassemia

• Severe anemia that reduces ability of the

blood to carry oxygen;

• nearly all affected infants are stillborn or die soon after birth.

• Primarily families of Malaysian, African, and Southeast Asian descent

• Frequent blood transfusions.

Beta thalassemia (Cooley's anemia)

• Severe anemia resulting in weakness, fatigue, and frequent illness;

• usually fatal in adolescence or young adulthood.

• Primarily families of Mediterranean descent

• Frequent blood transfusions

Cystic Fibrosis

• Overproduction of mucus, which collects in the lung and digestive tract;

• children do not grow normally and usually do not live beyond age 30;

• the most common inherited lethal defect among white people.

• 1 in 2,000 white births

• Daily physical therapy to loosen mucus;

• Antibiotics for lung infections;

• enzymes to improve digestion;

• gene therapy (in experimental stage).

Duchenne Muscular Dystrophy

Fatal disease usually found in males, marked by muscle weakness;

• minor mental retardation is common;

• respiratory failure and death usually occur in young adulthood.

• 1 in 3,000 to 5,000 male births

• No treatment.

Hemophilia

• Excessive bleeding, usually affecting males;

• in its most severe form, can lead to crippling

• arthritis in adulthood.

• 1 in 10,000 families with a history of

hemophilia

• Frequent transfusions of blood with clotting factors

Anencephaly

• Absence of brain tissues;

• infants are stillborn or die soon after birth.

• 1 in 1,000

• No treatment

Spina bifida

• Incompletely closed spinal canal, resulting in muscle weakness or paralysis and loss of bladder and bowel control;

• often accompanied by hydrocephalus, an accumulation of spinal fluid in the brain, which can lead to mental retardation

• 1 in 1,000

• Surgery to close spinal canal prevents further injury;

• shunt placed in brain drains excess fluid and prevents mental retardation

Phenylketonuria (PKU)

• Metabolic disorder resulting in mental retardation.

• 1 in 15,000 births

• Special diet begun in first few weeks of life can prevent mental retardation

Polycystic Kidney Disease

• Infantile form: enlarged kidneys, leading to respiratory problems and congestive heart failure.

• Adult form: kidney pain, kidney stones, and hypertension resulting in chronic kidney failure.

• 1 in 1,000

• Kidney transplants.

Sickle -cell anemia

• Deformed, fragile red blood cells that can clog the blood vessels, depriving the body of oxygen;

• symptoms include severe pain, stunted growth, frequent infections, leg ulcers, gallstones, susceptibility to pneumonia, and stroke.

• 1 in 500 African Americans

• Painkillers, transfusions for anemia and to prevent stroke, ant

XYY

Male;

• tall stature;

• tendency toward low IQ, especially verbal.

• 1 in 1,000 male births

• No special treatment.

XXX (TRIPLE X)

Female;

• normal appearance, menstrual irregularities, learning disorders, mental retardation.

• 1 in 1,000 female births

• Special education.

XXY (KLINEFELTER)

Male;

• sterility, underdeveloped secondary sex characteristics, small testes, learning disorders.

• 1 in 1,000 male births

• Hormone therapy, special education.

X0 (TURNER)

Female;

• short stature, webbed neck, impaired spatial abilities, no menstruation, infertility, underdeveloped sex organs, incomplete development of secondary sex characteristics.

• 1 in 1,500 to 2,500 female births

• Hormone therapy, special education.

Fragile X

Minor-to-severe mental retardation;

• symptoms, which are more severe in males, include delayed speech and motor development, speech impairments, and hyperactivity;

• the most common inherited form of mental retardation

• 1 in 1,200 male births;

• 1 in 2,000 female births

• Educational and behavioral therapies when needed.

Physical Change in Pregnancy

Tender, swollen breasts or nipples

• Fatigue; need to take extra naps

• Slight bleeding or

• cramping

• Food cravings

• Nausea with or without vomiting

• Frequent urination

• Frequent, mild headaches

• Constipation

• Mood swings

• Faintness and dizziness

• Raised basal body temperature

Gestation

• Period of development between conception and birth. Normal range of gestation is between 37 and 41 weeks.

Gestational Age -

Age of an unborn baby, usually dated from the first day of an expectant mother’s last menstrual cycle.

Cephalocaudal Principle

Development proceeds from the head to the lower part of the trunk. An embryo’s head, brain, and eyes develop earliest and are disproportionately large until the other parts catch up.

Proximodistal Principle

Development proceeds from parts near the center of the body to outer ones. The embryo’s head and trunk develop before the limbs, and the arms and legs before the fingers and toes.

Stages of Prenatal Development

Cephalocaudal Principle and Proximodistal Principle

Periods of Prenatal Development

Germinal Stage, Embryonic Stage, and Fetal Stage

Germinal Stage (Fertilization to 2 weeks)

Characterized by zygote’s rapid cell division, blastocyst formation, and implantation in the wall of the uterus.

Embryonic Stage (2 to 8 weeks)

Characterized by organogenesis, the rapid growth and development of major body systems and organs.

Embryo

most vulnerable to destructive influences in the prenatal environment.

Spontaneous Abortion (miscarriage)

Natural expulsion from the uterus of an embryo that cannot survive outside the womb.

Stillbirth

Miscarriage that occurs after 20 weeks of gestation.

Fetal Stage (8 weeks to birth)

-increased differentiation of body parts and greatly enlarged body size.

-250,000 immature neurons are produced every minute.

o Most of the neurons in the higher areas of the brain are in place by 20 weeks of gestation, and the structure becomes increasingly well-defined during the next 12 weeks.

o Both taste buds (taste) and olfactory receptors (smell) begin to form at about 8 weeks of gestation.

o From about the 12th week of gestation, the fetus swallows and inhales some of the amniotic fluid in which it floats.

o By about week 20, taste buds become functional, and shortly thereafter, so do olfactory receptors.

Environmental Influences: Maternal Factors

Teratogen

Nutrition and Maternal Weight

Malnutrition

Physical Activity at Work

Drug Intake

Maternal Illnesses

Maternal Emotional State

Maternal Age

Outside Environmental Hazards

Teratogen

Environmental agent, such as a virus, a drug, or radiation, that can interfere with normal prenatal development and cause developmental abnormalities.

Nutrition and Maternal Weight

Women who gain the recommended amount of weight are less likely to have birth complications or to bear babies whose weight at birth is dangerously low or overly high.

Malnutrition

When expectant mothers suffer from a calorie deficit, the results can be fetal growth restriction and low birth weight.

Physical Activity and Work

• Moderate exercise any time during pregnancy does not seem to endanger the fetuses of healthy women.

• Regular exercise reduces constipation and back pain, and it may lower the risk of complications such as gestational diabetes, preeclampsia, or cesarean delivery.

Drug Intake Components

Medical Drug

Opioids

Alcohol

Nicotine

Caffeine

Marijuana

Cocaine

Methamphetamine

Medical Drugs

o Antibiotic tetracycline

o Nervous system depressants

(barbiturates, opiates, etc.)

o Several hormones (diethylstilbestrol (DES) and androgens)

o Certain anticancer drugs (methotrexate)

o Accutane (drug for severe acne)

o Drugs used to treat epilepsy

o Several antipsychotic drugs

o Angiotensin-converting enzyme (ACE) inhibitors

o Nonsteroidal anti-inflammatory drugs (NSAIDs)

Opioids

Associated with small babies, fetal death, preterm labor, and aspiration of meconium (earliest stool produced by babies)

Neonate Abstinence Syndrome (withdrawal)

Newborns may show sleep disturbances, tremors, difficulty regulating their bodies, irritability and crying, diarrhea, fever, and feeding difficulties.

Fetal Alcohol Syndrome (FAS)

Characterized by a combination of retarded growth, face and body malformations, and disorders of the central nervous system.

Nicotine

o Women who smoke during pregnancy are more than 1½ times as likely as nonsmokers to bear low birth-weight babies.

o Women who smoke during pregnancy are also more like to miscarry or have birth complications, preterm babies, or babies that die from sudden infant death syndrome.

o Secondhand smoke exerts similar effects.

Caffeine

Caffeine intake under 300 milligrams a day is not associated with an increased risk of miscarriage, stillbirth, or birth defects.

Marijuana

exposure, especially at high levels, is associated with low birth weight, preterm delivery, difficult births, and admission into neonatal intensive care.

Cocaine

Associated with delayed growth, placental displacement, preterm delivery, low birth weight, small head size, and impaired neurological development.

Methamphetamine

o Physically, prenatal methamphetamine exposure is associated with preterm delivery, low birth weight, and reduced head circumference.

o Associated with fetal brain damage to areas of the brain involved in learning, memory, and control, which are likely to have longer-term consequences.

Maternal Illnesses

Acquired Immune Deficiency Syndrome (AIDS) and Rubella (German Measles)

Acquired Immune Deficiency Syndrome (AIDS)

▪ Viral disease that undermines effective functioning of the immune system.

▪ The virus may cross over to the fetus’s bloodstream through the placenta during pregnancy, labor, or delivery or, after birth, through breast milk.

Rubella (German Measles)

Disease that can cause miscarriage or stillbirth. Associated with cleft palate, deafness, and heart defects.

Maternal Emotional State

o A mother’s self-reported stress and anxiety during pregnancy, when chronically high, has been associated with a more active and irritable temperament in newborns, negative emotionality and impulsivity, and behavioral disorders in early childhood.

o Children born to depressed mothers are at elevated risk for developmental delays as toddlers, increased incidence of both internalizing (e.g., depression) and externalizing (e.g., impulsive behavior and aggression) symptoms as children, and elevated levels of violent and antisocial behaviors in adolescence.

Maternal Age

o Chance of miscarriage or stillbirth rises with maternal age.

o Women age 30 to 35 are more likely to suffer complications due to diabetes, high blood pressure, or severe bleeding.

o Higher risk of premature delivery, retarded fetal growth, birth defects, and chromosomal abnormalities, such as Down syndrome.

o Adolescent mothers tend to have premature or underweight babies—perhaps because a young girl’s still-growing body consumes vital nutrients the fetus needs or, more likely, because of inadequate or missing prenatal care.

Outside Environmental Hazards

o Air pollution, chemicals, and radiation

o Extremes of heat and humidity

Ultrasound (sonogram)

High-frequency sound waves directed at the mother’s abdomen produce a picture of fetus in uterus.

• Monitor fetal growth, movement, position, and form

• Detect major structural abnormalities or fetal death

• Assess amniotic fluid volume

• Judge gestational age

• Detect multiple pregnancies

Embryoscopy, fetoscopy

• Tiny viewing

scope is inserted

in woman’s

abdomen to view

embryo or fetus

• Guide fetal blood

transfusions and

bone marrow

transplants and

assist in diagnosis

of

nonchromosomal

genetic disorders

• Riskier than other

prenatal diagnosis

procedure

Amniocentesis

Sample of amniotic fluid containing fetal cells is withdraw under guidance of ultrasound and analyzed

• Usually performed in women aged 35 and older, can detect chromosomal disorders and certain genetic or multifactorial defects

• More than 99 percent accuracy rate

• Normally not performed before 15 weekss gestation, small (0.5-1%) added risk of fetal loss or injury

• Can be used for sex screening of unborn babies

Chorionic villus sampling (CVS)

Tissues from chorionic villi (projections of membranes surrounding fetus) are removed and analyzed

• Early diagnosis of birth defects and disorders, can be performed between 10 and 12 weeks’ gestation

• Should not be performed before 10 weeks’ gestation

• May be slightly riskier than amniocentesis

Preimplantation genetic diagnosis

• After in vitro fertilization, sample cell is removed from the blastocyst and analyzed

• Can avoid transmission of genetic defects or predispositions known to run in the family

• A defective blastocyst is not implanted in uterus

Umbilical cord sampling (cordocentesis or fetal blood sampling)

Needle guided by ultrasound is inserted into blood vessels of umbilical cord

• Allows direct access to fetal DNA diagnosis measures including blood disorders and infections, and therapeutic measures such as blood transfusions

• Fetal loss or miscarriage is reported in 1-2% of cases

• Increases risk of bleeding from umbilical cord and fetal distress

Maternal blood test (including prenatal cell free DNA scans)

A sample of the prospectively mother’s blood is tested for alpha fetoprotein or for fetal DNA

• May indicate defects in formation of brain or spinal cord (anencephaly or spina bifida)

• Also can predict down syndrome and other abnormalities

• No known disks,but false negatives are possible

• Ultrasound and/or amniocentesis is needed to confirm suspected conditions

THE BIRTH PROCESS

Labor, Parturition, Braxton-Hicks Contractions

Labor

Apt term for the process of giving birth.

Parturition

• Act or process of giving birth.

• Typically begins about 2 weeks before delivery.

Braxton-Hicks Contractions

False contractions during the final months of pregnancy or even as early as the 2nd trimester.

First Stage

• Dilation of the cervix.

• Typically lasting 12 to 14 hours for a woman having her first child.

• Regular and increasingly frequent uterine contractions—15 to 20 minutes apart at first—cause the cervix to shorten and dilate, or widen, in preparation for delivery.

• This stage lasts until the cervix is fully open (10 centimeters, or about 4 inches) so the baby can descend into the birth canal.

Second Stage

• Descent and emergence of the baby.

• Typically lasts up to an hour or two.

• Begins when the baby’s head begins to move through the cervix into the vaginal canal, and it ends when the baby emerges completely from the mother’s body.

• At the end of this stage, the baby is born but is still attached to the placenta in the mother’s body by the umbilical cord, which must be cut and clamped.

Third Stage

• Expulsion of the placenta.

• Lasts between 10 minutes and 1 hour.

• The placenta and the remainder of the umbilical cord are expelled from the mother.

ELECTRONIC FETAL MONITORING

• Mechanical monitoring of fetal heartbeat during labor and deliver

•Most commonly done with the use of sensors attached to the woman’s midsection and held in place with an electric belt.

• Has a high false positive rate.

Vaginal Delivery

Usual method of childbirth.

Cesarean Delivery

Delivery of a baby by surgical removal from the uterus.

• May be performed when labor progresses too slowly, when the fetus is in the breech (feet or buttocks first) or transverse (lying crosswise in the uterus) position, or when the mother is bleeding vaginally.

• Can lead to bleeding, uterine rupture, and heightened risks of problems in future pregnancies.

Natural Childbirth

Method of childbirth that seeks to prevent pain by eliminating the mother’s fear through education about the physiology of reproduction and training in breathing and relaxation during delivery.

Lamaze Method

The woman is trained to pant or breathe rapidly in sync with her contractions and to concentrate on other sensations to ease the perception of pain.

Prepared Childbirth

Method of childbirth that uses instruction, breathing exercises, and social support to induce controlled physical responses to uterine contractions and reduce fear and pain.