1. Nature and Nurture in Psychology
Module 3, Chapter 1

2. Important questions to ask
What makes you, you?
How do our families, our friends, and our culture in which we live affect us?
This is what behavior genetics focuses on.
Socio-cultural perspective anyone?
If you were cloned at birth, would your clone be exactly like you?

3. Behavior Genetics
Studies the relative effects of genes and environmental influences on behavior.
Genes – biochemical units of heredity that make up chromosomes; a segment of DNA.
Set up our physical beings and influence behavior.
Environment – every non-genetic influence, from prenatal nutrition to the people and things around us.
Culture you are raised in, socio-economic status, family.

4. Nature and Nurture
Nature side entails the genetic code passed from parent to child.
Biology
Nurture side involves all environmental influences from prenatal development on.
Environment
Which parts of human behavior can we attribute to nature and which can be attributed to nurture?

5. Genetics in Brief We all have our own genetic code.
Biological blueprint found in every cell nucleus that contains master code for your entire body.
Chromosomes – threadlike structures made of DNA molecules that contain the genes.
46 in each cell, 23 from each parent.
DNA – complex molecule containing the genetic info that makes up the chromosomes.

6. Genes: Chromosomes Location & Composition

7. Genome Nucleotides
The complete genetic instructions for a given organism
All the genetic material in an organism’s chromosome pattern
The four letter code to distinguish genes
Letters A,T,C, or G are used

8. Mutation Genetic Predisposition
Random errors in the replication of genes from parent to child which result in change of an individual’s genetic code
Can be desirable or undesirable changes
Superior eyesight, or predisposed to cancer.
The possibility of something happening through the genetic code
Genetics creates the potential for something
The environment may or may not trigger the predisposition
Genetic traits and diseases, sun burn easily, etc.

9. Nature and Similarity Similarities Evolutionary Psychology
99% of all humans genetic make up is the same!
Despite our differences, human beings throughout the world share a number of similarities…how so?
Evolutionary Psychology
The study of evolution of behavior and the mind
Uses the principle of natural selection
We have similar genes b/c we are all from people who used similar practices to survive.
Natural Selection
Darwin’s principle that those traits contributing to the survival of the species will most likely be passed on to the next generation
Discover thru trail and error what foods are okay to eat.

10. Nature and Individual Differences: Twin Studies
Anyone know any twins?
How are they alike
and how are they different?

11. Identical Twins Fraternal Twins
Nature’s human clones.
Twins who developed from a single fertilized egg
Are genetically identical
Called monozygotic twins
Twins who developed from separate eggs
Genetically no different than other siblings
Called dizygotic twins

12. Heritability
What has been inherited from your family and genetic code?
The proportion of an individual’s characteristics that can be attributed to genetics (heredity)
The degree to which traits are inherited.

13. Twin Studies Used to determine the heritability of a given trait
Data is collected from both identical and fraternal twins on the trait
Compare the data between the two groups
Important not to conclude that a specific behavior is inherited, just the genetic predisposition to that behavior (anger, conflict, etc.).

14. Adoption Studies
Compare adopted children’s traits with those of their biological parents and their adopted parents
Trait similarities with biological parents: attribute the trait to heredity
Trait similarities with the adopted parents: attribute the trait to the environment

15. Environment Matters: Early Learning and Brain Development
Did you know that genetic traits account for about half of our personality traits?
And growing up in the same house only accounts for 10% of our personalities?
Look at page 45 for a story.

16. Early Brain Development
Use it or lose it!
Experience nurtures nature (????)
Ex: I don’t remember science learned in the 5th grade, so “no, in some cases I am not smarter than a 5th grader”.
Ex: If you roller blade in elementary school, but don’t again until you are 21…you might have to re-learn.
Early experience is critical in brain development (in order for us to reach our full potential).
In later life continued use is necessary to maintain neural connections in the brain.

17. Look at how much nurture can affect: Examples from page 60:
Rats house for 60 days in an enriched (fun, stimulating) environment had brain weight increases of 7-10% more than rats housed in an impoverished (boring) environment.
Premature babies who receive special handling (touch, massage) grow more rapidly physically and neurologically than preemies who do not receive the same treatment.

18. What are Feral Children?
How did their environment impact them?
How about their nature?

19. Environment Matters: Peer Influence Cultural Influence
Peer influence in adolescence is very powerful.
Many studies suggest a peer group is correlated with school performance, smoking, and other behaviors.
Ex: If your group of friends doesn’t do drugs… you probably won’t either.
Shared attitudes, beliefs, norms and behaviors of a group
Culture is communicated from one generation to the next
Influences our:
Food selection, religious choices, family activities, etc.
Tend to think your culture is the best.

20. Norms: What is Normal?
Understood rules for accepted and expected behavior
Consist of the “proper behavior” within a group
So what the heck does normal mean, anyway?

21. Collectivism Individualism
Giving priority to the goals of one’s group over one’s personal goals
Defining one’s identity in terms of the group’s identification rather than personal attributes
See people as connected to others
Individual needs are sacrificed for the good of the group.
Giving priority to one’s goals over the goals of the group
Defining one’s identity in terms of personal attributes rather than the group’s identification
Tend to see people as separate and independent