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)