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