PSYCH week 3

Question 1

Describe what is meant by “nature”, what is meant by “nurture.”

Answer 1

Nature- our inborn characteristics. It is our behaviors, and patterns which come from our genetics.
Nurture- The characteristics we learn throughout our lives. It is the things that we are taught in life.

Question 2

Describe what makes nature-nurture questions so difficult to answer.

Answer 2

The two pieces are directly intertwined, and separating them is basically impossible in most instances. It’s hard to figure out the exact degree to which each one plays a part, and usually multiple genes affect one trait. And, you can’t perform a controlled experiment to make certain people have and raise children for science.

Question 3

Describe the goal of behavioral genetics and some examples of how both nature and nurture contribute to traits.

Answer 3

To study of genes and environment combine to generate behavior, ex. violin playing, having good fingers to play with is nature, but practice is nurture, and perfect pitch is both.

Question 4

Explain the types of questions that can be answered with adoption and twin studies, and list the the pros and cons for each.

Answer 4

Adoption studies - When a child is put up for adoption, researchers follow up to see what kind of characteristics the child has with the birth parents, and what is similar to their adoptive parents.
Twin Studies - Researchers study identical and fraternal twins, to see what things are similar and different between the two types, because fraternal twins have different DNA, which identical twins have the same DNA.

Question 5

Know the major research designs that can be used to study nature–nurture questions.

Answer 5

Dizygotic twins, Monozygotic twins, Twin studies, Adoption studies

Question 6

Dizygotic twins

Answer 6

“fraternal” twins, develop from two zygotes and share 50% of their DNA

Question 7

Monozygotic twins

Answer 7

“identical” twins, result from a single zygote (fertilized egg) and have the same DNA

Question 8

Twin studies

Answer 8

A behavior genetic research method that involves comparison of the similarity of identical (monozygotic; MZ) and fraternal (dizygotic; DZ) twins.

Question 9

Adoption studies

Answer 9

A behavior genetic research method that involves comparison of adopted children to their adoptive and biological parents.

Question 10

Explain what the heritability coefficient is and some of its pitfalls.

Answer 10

A number from 0 to 1 which tries to tell us how strongly a gene influences a certain trait. They also treat the environment and genes are completely separate things, and ignores the ways that they may interact.

Question 11

Quantitative genetics

Answer 11

Scientific and mathematical methods for inferring genetic and environmental processes based on the degree of genetic and environmental similarity among organisms.

the study of the genetic basis underlying phenotypic variation among individuals

Question 12

Evolution

Answer 12

Change over time. Is the definition changing?

Question 13

Define the primary mechanisms by which evolution takes place.

Answer 13

natural selection, adaptations, sexual selection

Question 14

Define sexual selection and its two primary processes.

Answer 14

The evolution of characteristics is because of the mating advantage they give organisms.

intrasexual competition
A process of sexual selection by which members of one sex compete with each other, and the victors gain preferential mating access to members of the opposite sex.

intersexual selection
A process of sexual selection by which evolution (change) occurs as a consequence of the mate preferences of one sex exerting selection pressure on members of the opposite sex.

Question 15

adaptations

Answer 15

Evolved solutions to problems that historically contributed to reproductive success

Question 16

natural selection

Answer 16

Differential reproductive success as a consequence of differences in heritable attributes

Question 17

Gene Selection Theory

Answer 17

The modern theory of evolution by selection by which differential gene replication is the defining process of evolutionary change.
or
Genes that are better able to encourage the organism to reproduce, and thus replicate themselves in the organism’s offspring, have an advantage over competing genes that are less able.

Question 18

psychological adaptations:

Answer 18

Mechanisms of the mind that evolved to solve specific problems of survival or reproduction; conceptualized as information processing devices.

Question 19

the core premises of sexual strategies theory.

Answer 19

Sexual strategies theory is based on sexual selection theory. It proposes that humans have evolved a list of different mating strategies, both short-term and long-term, that vary depending on culture, social context, parental influence, and personal mate value (desirability in the “mating market”).

It started by looking at the minimum parental investment needed to produce a child. For women, even the minimum investment is significant: after becoming pregnant, they have to carry that child for nine months inside of them. For men, on the other hand, the minimum investment to produce the same child is considerably smaller—simply the act of sex.

Question 20

Identify the core premises of error management theory (EMT), and provide two empirical examples of adaptive cognitive biases.

Answer 20

A theory of selection under conditions of uncertainty in which recurrent cost asymmetries of judgment or inference favor the evolution of adaptive cognitive biases that function to minimize the more costly errors.
It helps us be safe from harm

Example one:
You hear a rustle in the leaves on the path in front of you. It could be a snake.
Example two:
the auditory looming bias: Have you ever noticed how an ambulance seems closer when it’s coming toward you, but suddenly seems far away once it’s immediately passed? With the auditory looming bias, people overestimate how close objects are when the sound is moving toward them compared to when it is moving away from them

Question 21

Explain what the term epigenetics means and the molecular machinery involved.

Answer 21

epigenetics — The study of heritable changes in gene expression or cellular phenotype caused by mechanisms other than changes in the underlying DNA sequence. Epigenetic marks include covalent DNA modifications and posttranslational histone modifications

Question 22

Name and discuss important neural and developmental pathways that are regulated by epigenetic factors, and provide examples of epigenetic effects on personality traits and cognitive behavior.

Answer 22

-DNA methylation: process in which methyl groups are added to a DNA molecule, the effect depends on the stage of development and location of the cytosine it binds too, but usually results in silencing or reduced gene expression, powerful regulatory method
Acetylation of histones: process of introducing an acetyl group, generally associated with DNA de-methylation and gene expression
-nutrients can affect these processes
-these can be crucial for the development of mature neural networks that support emotional, cognitive, and social behaviour

EXAMPLES
- methylation of the glucocorticoid receptor may be an early epigenetic marker of hormonal activity
-increased methylation of this receptor causes a reduced expression which can increase hormonal stress response
-DNA methylation has been implicated in the maintenance of long term memories
-changes in histone modification can influence long term memory by altering chromatin accessibility

Question 23

how misregulation of epigenetic mechanisms can lead to disease states, and be able to discuss examples.

Answer 23

-events that alter chromatin structure to regulate programs of gene expression can lead to symptoms of depression

Question 24

Recognize how epigenetic machinery can be targets for therapeutic agents, and discuss examples.

Answer 24

-epigenetic DNA modifications have been discovered that may overcome long-lasting effects of environment on behaviour

Question 25

DNA methyltransferases (DNMTs)

Answer 25

Enzymes that establish and maintain DNA methylation using methyl-group donor compounds or cofactors. The main mammalian DNMTs are DNMT1, which maintains methylation state across DNA replication, and DNMT3a and DNMT3b, which perform de novo methylation.

Question 26

DNA methylation

Answer 26

Covalent modifications of mammalian DNA occurring via the methylation of cytosine, typically in the context of the CpG dinucleotide

Question 27

Gene

Answer 27

A specific deoxyribonucleic acid (DNA) sequence that codes for a specific polypeptide or protein or an observable inherited trait.

Question 28

Phenotype

Answer 28

The pattern of expression of the genotype or the magnitude or extent to which it is observably expressed—an observable characteristic or trait of an organism, such as its morphology, development, biochemical or physiological properties, or behavior.

Question 29

Histone modifications

Answer 29

Posttranslational modifications of the N-terminal “tails” of histone proteins that serve as a major mode of epigenetic regulation. These modifications include acetylation, phosphorylation, methylation, sumoylation, ubiquitination, and ADP-ribosylation.

Question 30

Histone acetyltransferases (HATs) and histone deacetylases (HDACs)
HATs are enzymes that transfer acetyl groups to specific positions on histone tails, promoting an “open” chromatin state and transcriptional activation. HDACs remove these acetyl groups, resulting in a “closed” chromatin state and transcriptional repression.

Answer 30

HATs are enzymes that transfer acetyl groups to specific positions on histone tails, promoting an “open” chromatin state and transcriptional activation. HDACs remove these acetyl groups, resulting in a “closed” chromatin state and transcriptional repression.