Module 14: Behavior Genetics: Predicting Individual Differences Flashcards
Behavior Genetics
The study of the relative power and limits of genetic and environmental influences on behavior
Environment
EVERY external influence! (including prenatal nutrition - and the people and things that surround us
Chromosomes
Threadlike structures made of DNA molecules that contain the genes
Deoxyribonucleic acid (DNA)
Complex molecule that contains the genetic information
- DNA makes up chromosomes
Genes
- biochemical units of heredity
- composed of segments of DNA capable of synthesizing proteins
Genome
The complete instructions for making an organism
- consist of genetic materials that are in the organism’s chromosomes
What do behavior geneticist study?
They study the differences, effects, & interplay of heredity and the environment
How many chromosomes do we have? How many come from the egg? From the sperm?
46 chromosomes total
23 mother’s egg
23 father’s sperm
How many genes to people have?
Between 20,000-25,000 genes
What are the two types of genes?
expressed (active) or inactive genes
What “turn on” genes? What happens as a result?
The environment turns on genes. Those genes provide the code for creating protein molecules (body’s building blocks)
Is a trait influenced by a single gene?
No, Traits are influenced by many genes
Note: Complex traits such as intelligence, happiness, aggressiveness, etc., are influenced by groups of genes
What helps explain both our shared human nature and our human diversity?
Our genetic predispositions/ our genetically influenced traits
Monozygotic (Identical Twins)
- one fertilized egg that splits
- two genetically identical organisms
Dizygotic (Fraternal Twins)
- two fertilized egg
- share the SAME fetal environment
- genetically simular as other siblings
True or False: Identical twins don’t always have the same number of copies of those genes
True: Helps explain why one twin may be more at risk for certain illnesses
What could be a cause of differences between identical twins?
Having different placentas
- 1 out of every 3 pairs of twins have separate placentas
- one may receive more nourishment than the other
Not having the same number of copies
True or False: Identical twins are not more similar on extroversion & neuroticisms (emotional stability) scales than fraternal twins
False
Identical twins are more similar on extroversion and neuroticism
True or False: Studies have shown that identical twins whose parents treated them alike were NOT psychologically more alike than identical twins who were treated less similarly
True
Identical twins are not psychologically more alike even if the parents treated them similarly
What are some attributes that seperated twins share?
- similar taste, physical attributes, personality (characteristic patterns of thinking, feeling, & acting), ability, attitude, interest & fears
- brain waves & speech inflection are similar
Note: validity is questioned because adoption agencies try to place twins in similar environments
Genetic Relatives
Biological parents & siblings
Environmental Relatives
Adoptive parents & siblings
Are people who grew up together (related or not) more alike in regards to personality?
No
People who grew up together, related or not, do not resemble one another in personality
Are adoptees more like their biological or adoptive parents?
Adoptees are more similar to biological parents in regards to agreeableness & extroversion
Do parents influence children’s attitude, values, manners, faith, and politics?
yes parents do influence children’s attitude, values, manners, faith, and politics.
Molecular Genetics
- subfield of biology
- studies molecular structures & functions of genes
What is the goal of molecular geneticist?
The goal is to find some of the genes that work to form traits (body weight, extraversion, sexual orientation, etc._
What can genetic test do?
Genetic test can pinpoint and aid in identifying people with genes that put them at risk of genetically influenced disorders (learning disorders, depression, schizophrenia , alcohol use disorder)
What is a problem of identify genes?
Moral issue: people could try to genetically modify their children
- can cause discrimination issues
- could result in the loss of other traits ex. Schizophrenia linked with creativity
Heritability
The portion of variation among individuals that we can attribute to genes
The EXTENT to which differences among people are attributed to genes
Remember heritability of a trait varies depending on the range of the population and the environment
What is something to remember when measuring a person’s ______ ? (extroversions for example)
Putting people in a new social context can change their ______ (extroversion in this example)
REMEBER
“Genes & environment - nature & nurture - work together like two hands clapping. Genes are self -regulating”
True or False: An effect of an environment can not also be an adaptation
False
An effect of an environment CAN also be an adaptation
example: calloused feet - tough environment
Interaction
The interplay that occurs when the effect of one factor depends on another factor
ex: effect of one factor (environment) depends on another (heredity)
Epigenetic
The study of environmental influences on gene expression that occurs WITHOUT a change in DNA
What blocks gene expression?
Epigenetic molecules
What can effect how a child remembers their childhood?
Evocative interactions affect how children remember their childhood. For instance how their parents treated them
*not all that + about this one
Epigenetic Mark
An organic methyl molecule attached to part of a DNA strained
- effects could last over lifetimes
What can affect the epigenetic molecules that regulate gene expression?
Diet, drugs, & stress
Heredity (nature)
genetic transfer of characteristics to offspring from parent
Human Genome
the complete instructions for humans that all humans (genome); there is a common sequence within human DNA (human)
If the differences to an environment decrease what happens to the heritability? Why?
The heritability would increase because any difference noticed we be a result of their genes not their environment
Molecular Behavior Genetics
The further study of how the structure and function of genes interact with our environment to influence behavior.
