Test 1 Flashcards
Why does childhood exist?
Walking upright narrows the possible size of the birth canal.
Newborn infants’ heads can only reach a certain size before both mother and child die during childbirth.
Processes that were once prenatal in our ancestors became postnatal for humans.
Primates’ brain growth occurs mostly in utero.
Brains are 70% developed at birth and reach full maturity within the next 6 months.
At birth, the human brain has reached only 23% of its full weight.
The brain triples in size over the first 3 years of life.
Human brain is not fully mature until the mid 20’s.
What are the disadvantages of long childhoods?
requires greater parental investment
increases the risk that offspring will die before reproducing
What are the four themes in CD?
- Continuity and Discontinuity
- Nature and Nurture
- Active vs. Passive Child
- Links between domains
What term describes the fact that experience can alter the expression of genes, and genes influence the experiences we seek out?
Bidirectional influences
Alternative term for the nature vs. nurture debate
Nativists vs. Empiricists
Provide examples of links between domains
Increases in motor development lead to increases in cognitive development
Increases in language development lead to increases in emotional development
Define “gene”
a segment of DNA that acts as instructions for creating a particular protein
What are chromosomes, and how many do humans have?
Humans have 46 chromosomes total
Chromosomes are made up of thousands of genes, long strands of DNA
What is the term for the development that results from the bidirectional interactions between genotype and environment?
Epigenisis
Provide examples of epigenesis
Environmental factors such as food, drugs, or toxins can cause epigenetic changes by alteringthe way molecules bind to DNA or changingthe structure of proteins that DNA wraps around.
These structural changes can result in slight changesin gene activity
They also can produce more dramaticchanges by switching genes on when theyshould be off or vice versa.
Example: girls usually begin menstruating between the ages of 11-16. It is part of the genotype for girls to begin menstruating around these ages. The exact age is determined by environmental influences: Anorexia, extreme exercise, obesity, exposure to hormones from food
Provide an example of reaction range
In Western countries, height rose steadily for the first half of the 20th century as nutrition improved.
Genes themselves did not change within one generation; the environment allowed the phenotype to reach a higher point in the possible reaction range.
Define “passive effects”
During infancy, individuals’ environments are provided by their parents. The rearing environment reflects the parents’ genes.
Define “evocative effects”
A person’s inherited characteristics evoke responses from others in their environment.
Define “active effects”
People pay attention to aspects of environments that best correspond with their genotype.
They actively seek out environments that correspond to their genotypic characteristics.
Niche-picking
Effects Over Time: When does each effect have the most influence?
In childhood, passive effects are especially pronounced
Active effects are relatively weak
Define “reaction range”
an individual genotype establishes a range of possible responses to different
kinds of life experiences: the so-called range of reaction. . In other words, Gottesman
claims that genotype sets boundaries on the range of possible phenotypes that one
might display to different environments.
What is the term for the process of seeking out environments that fit one’s heredity?
Define “niche picking”
What is the fertilized egg called (weeks 1-2)?
Zygote
What is a blastocyst and when does it form?
4 days after fertilization, when growth becomes a hollow ball with 100 cells
What and when is the next step after blastocyst formation?
Implantation- blastocyst burrows into the uterine wall
What is the cluster of cells in the center of the blastocyst called?
Germ disc (eventually to become the baby)
What does the layer of cells of the blastocyst closest to the uterus become?
Placenta
When is an “embryo” in existence? (event and time period)
When blastocyst is completely embedded in the uterine wall. Embryo is weeks 3-8.
What does the amniotic sac do?
cushions the embryo and helps maintain its temperature
What does the umbilical cord connect the embryo to?
Placenta
What weeks of pregnancy are called the “fetus”?
9-38
What drug led to deformed limbs?
Thalidomide, for morning sickness
What are the three primary types of teratogens?
Diseases, drugs, environmental hazards
Define “neuron”
A cell that specializes in receiving and transmitting information
What is the receiving end of the neuron called?
Dendrite
What is the end of the neuron that sends info out called?
Axon
What is myelin?
A fatty sheath that allows neurons to transmit information more rapidly
How does information travel between neurons?
Neurotransmitters cross synapses
What is the first stage of brain development?
3 weeks after conception- neural plate
What happens in brain development four weeks after conception?
The neural plate folds into a tube that ultimately becomes the brain and spinal cord
When does production of neurons begin?
10 weeks after conception, once the ends of the neural tube have fused shut
What part of the brain is developed first? Last?
Innermost layers are built first
When are all six layers of the brain complete?
7 months after conception
When does acquirement of myelin begin? End?
4 months after conception until early adulthood
What are the benefits of breastfeeding?
Like formula, breast milk provides the proper nutrients for a child’s growth.
Breast milk contains antibodies that protect child from illness.
Breast fed infants are less prone to digestive problems (diarrhea and constipation), and transition to solid foods more easily because they are accustomed to breast milk changing tastes. Also, in areas with sanitation issues, breastmilk cannot be contaminated the way formula can. Formula-fed infants are more likely to develop allergies.
Why do teratogens have differential effects?
Effects depend on: genotype of organism (for example, thalidomide did not harm rats or rabbits, not did it harm all embryos that encountered it), timing (exposure for zygotes usually causes spontaneous abortion, type of teratogen (i.e. rubella will affect the heart, eyes, and ears, but not the limbs), dose
What is it called when the neural plate folds into a tube, and when does this occur?
Neurulation, 3-4 weeks after gestation
What are the four stages of neural development?
Neurulation, proliferation, migration, differentiation
What is the difference between gray and white matter?
Gray matter and synapses decline in teens and twenties; white matter grows into thirties. White matter is composed of myelinated axons; gray matter is composed of nerve cell bodies and dendrites.
What are the two types of synaptogenesis?
Experience-expectant, experience-dependent
Why is mother stress a risk during the prenatal period?
Weakened immune system, less likely to get adequate sleep and nutrition, stress turns “off” genes that help regulate behavior in fetuses
What are the greatest risks to the developing child?
malnutrition, anorexia/bulimia, obesity, diseases, accidents
What might environmental factors do to DNA and proteins?
Alter the way molecules bind to DNA, change the structure of the protein that the DNA wraps around
What are causes of early puberty?
Obesity Environmental contaminants Estrogen related chemicals and hormones Social Environments Inadequate resources High stress Insecure attachment Father absence
Why might absence of an active father lead to earlier puberty in girls?
mating strategy of short term bonds and limited parental investment. Women have greater investment in offspring, and thus should be more sensitive to environmental factors related to rearing offspring
What are the effects of early maturation for girls?
Lower self esteem
Higher rates of anxiety, depression, and eating disorders
More likely to engage in drug/alcohol use
Display problems in school
Engage in sexual activity earlier
What are the effects of early maturation for boys?
More popular
Self assured
Sociable
Higher achievement aspirations
Why is early maturation a better psychological experience for boys than for girls?
Unlike girls, are not overly conspicuous
Growth is seen as positive
Tend to excel in sports
