Nature and Nurture Nature and Nurture in Psychologyin Psychology

Module 3, Chapter 1Module 3, Chapter 1

** Write the heading and all that’s underlined!**** Write the heading and all that’s underlined!**

Important questions to askImportant questions to ask

What makes you, you?What makes you, you?

How do our families, our friends, and our How do our families, our friends, and our culture in which we live affect us?culture in which we live affect us? This is what behavior genetics focuses on.This is what behavior genetics focuses on. Socio-cultural perspective anyone?Socio-cultural perspective anyone?

If you were cloned at birth, would your clone If you were cloned at birth, would your clone be exactly like you?be exactly like you?

Behavior GeneticsBehavior Genetics

Studies the relative effects of genes and Studies the relative effects of genes and environmental influences on behavior.environmental influences on behavior.

Genes – biochemical units of heredity that Genes – biochemical units of heredity that make up chromosomes; a segment of DNA.make up chromosomes; a segment of DNA. Set up our physical beings and influence behavior.Set up our physical beings and influence behavior.

Environment – every non-genetic influence, Environment – every non-genetic influence, from prenatal nutrition to the people and from prenatal nutrition to the people and things around us.things around us. Culture you are raised in, socio-economic status, Culture you are raised in, socio-economic status,

family.family.

Nature and NurtureNature and Nurture

NatureNature side entails the genetic code passed side entails the genetic code passed from parent to child.from parent to child. BiologyBiology

NurtureNurture side involves all environmental side involves all environmental influences from prenatal development on.influences from prenatal development on. EnvironmentEnvironment

Which parts of human behavior can we Which parts of human behavior can we attribute to nature and which can be attributed attribute to nature and which can be attributed to nurture?to nurture?

Genetics in BriefGenetics in Brief

We all have our own genetic code.We all have our own genetic code. Biological blueprint found in every cell nucleus Biological blueprint found in every cell nucleus

that contains master code for your entire body.that contains master code for your entire body. Chromosomes – threadlike structures made of Chromosomes – threadlike structures made of

DNA molecules that contain the genes.DNA molecules that contain the genes. 46 in each cell, 23 from each parent.46 in each cell, 23 from each parent.

DNA – complex molecule containing the DNA – complex molecule containing the genetic info that makes up the chromosomes.genetic info that makes up the chromosomes.

Genes: Genes: ChromosomesChromosomes Location & CompositionLocation & Composition

GenomeGenome NucleotidesNucleotides

The complete The complete genetic genetic instructions for a instructions for a given organismgiven organism

All the genetic All the genetic material in an material in an organism’s organism’s chromosome chromosome patternpattern

The four letter The four letter code to code to distinguish genesdistinguish genes

Letters A,T,C, or Letters A,T,C, or G are usedG are used

MutationMutation Genetic Predisposition Genetic Predisposition

Random errors in the Random errors in the replication of genes replication of genes from parent to child from parent to child which result in change which result in change of an individual’s of an individual’s genetic codegenetic code

Can be desirable or Can be desirable or undesirable changesundesirable changes Superior eyesight, or Superior eyesight, or

predisposed to cancer.predisposed to cancer.

The possibility of The possibility of something happening something happening through the genetic codethrough the genetic code

Genetics creates the Genetics creates the potential for somethingpotential for something

The environment may The environment may or may not trigger the or may not trigger the predispositionpredisposition

Genetic traits and Genetic traits and diseases, sun burn diseases, sun burn easily, etc.easily, etc.

Nature and SimilarityNature and Similarity SimilaritiesSimilarities

99% of all humans genetic make up is the same!99% of all humans genetic make up is the same! Despite our differences, human beings throughout the world share Despite our differences, human beings throughout the world share

a number of similarities…how so?a number of similarities…how so?

Evolutionary PsychologyEvolutionary Psychology The study of evolution of behavior and the mindThe study of evolution of behavior and the mind Uses the principle of natural selectionUses the principle of natural selection We have similar genes b/c we are all from people who used similar We have similar genes b/c we are all from people who used similar

practices to survive.practices to survive.

Natural SelectionNatural Selection Darwin’s principle that those traits contributing to the survival of Darwin’s principle that those traits contributing to the survival of

the species will most likely be passed on to the next generationthe species will most likely be passed on to the next generation Discover thru trail and error what foods are okay to eat.Discover thru trail and error what foods are okay to eat.

Nature and Individual Nature and Individual Differences: Differences: Twin StudiesTwin Studies

Anyone know any twins?Anyone know any twins?

How are they alike How are they alike

and how are they different?and how are they different?

Identical TwinsIdentical Twins Fraternal TwinsFraternal Twins

Nature’s human Nature’s human clones.clones.

Twins who Twins who developed from developed from a single a single fertilized eggfertilized egg

Are genetically Are genetically identicalidentical

Called Called monozygotic monozygotic twinstwins

Twins who Twins who developed from developed from separate eggsseparate eggs

Genetically no Genetically no different than different than other siblingsother siblings

Called Called dizygotic twinsdizygotic twins

HeritabilityHeritability

What has been inherited from your family What has been inherited from your family and genetic code?and genetic code?

The proportion of an individual’s The proportion of an individual’s characteristics that can be attributed to characteristics that can be attributed to genetics (heredity)genetics (heredity)

The degree to which traits are inherited.The degree to which traits are inherited.

Twin StudiesTwin Studies

Used to determine the heritability of a Used to determine the heritability of a given traitgiven trait

Data is collected from both identical and Data is collected from both identical and fraternal twins on the traitfraternal twins on the trait

Compare the data between the two groupsCompare the data between the two groups Important not to conclude that a specific Important not to conclude that a specific

behavior is inherited, just the genetic behavior is inherited, just the genetic predisposition to that behavior (anger, predisposition to that behavior (anger, conflict, etc.).conflict, etc.).

Adoption StudiesAdoption Studies

Compare adopted children’s traits with Compare adopted children’s traits with those of their biological parents and their those of their biological parents and their adopted parentsadopted parents

Trait similarities with biological parents: Trait similarities with biological parents: attribute the trait to heredityattribute the trait to heredity

Trait similarities with the adopted Trait similarities with the adopted parents: attribute the trait to the parents: attribute the trait to the environmentenvironment

Environment Matters: Environment Matters: Early Learning and Early Learning and Brain DevelopmentBrain Development

Did you know that genetic traits account for about Did you know that genetic traits account for about half of our personality traits?half of our personality traits?

And growing up in the same house only accounts And growing up in the same house only accounts for 10% of our personalities? for 10% of our personalities?

Look at page 45 for a story.Look at page 45 for a story.

Early Brain DevelopmentEarly Brain Development

Use it or lose it!Use it or lose it! Experience nurtures nature (????)Experience nurtures nature (????)

Ex: I don’t remember science learned in the 5Ex: I don’t remember science learned in the 5 thth grade, so grade, so “no, in some cases I am not smarter than a 5“no, in some cases I am not smarter than a 5thth grader”. grader”.

Ex: If you roller blade in elementary school, but don’t Ex: If you roller blade in elementary school, but don’t again until you are 21…you might have to re-learn.again until you are 21…you might have to re-learn.

Early experience is critical in brain Early experience is critical in brain developmentdevelopment (in order for us to reach our full (in order for us to reach our full potential).potential).

In later life continued use is necessary to In later life continued use is necessary to maintain neural connections in the brain.maintain neural connections in the brain.

Look at how much nurture can affect!Look at how much nurture can affect!Examples from page 60:Examples from page 60:

Rats house for 60 days in an enriched (fun, Rats house for 60 days in an enriched (fun, stimulating) environment had brain weight stimulating) environment had brain weight increases of 7-10% more than rats housed in increases of 7-10% more than rats housed in an impoverished (boring) environment.an impoverished (boring) environment.

Premature babies who receive special handling Premature babies who receive special handling (touch, massage) grow more rapidly physically (touch, massage) grow more rapidly physically and neurologically than preemies who do not and neurologically than preemies who do not receive the same treatment.receive the same treatment.

What are What are Feral Children?Feral Children?

How did their environment impact them?How did their environment impact them?

How about their nature?How about their nature?

Environment Matters:Environment Matters:Peer InfluencePeer Influence Cultural InfluenceCultural Influence Peer influence Peer influence in in

adolescence is very adolescence is very powerful.powerful.

Many studies suggest a Many studies suggest a peer group is correlated peer group is correlated with school with school performance, smoking, performance, smoking, and other behaviorsand other behaviors.. Ex: If your group of Ex: If your group of

friends doesn’t do friends doesn’t do drugs… you probably drugs… you probably won’t either.won’t either.

Shared attitudes, beliefs, Shared attitudes, beliefs, norms and behaviors of norms and behaviors of a groupa group

Culture is Culture is communicated from one communicated from one generation to the nextgeneration to the next

Influences our:Influences our: Food selection, religious Food selection, religious

choices, family choices, family activities, etc.activities, etc.

Tend to think your Tend to think your culture is the best.culture is the best.

Norms: What is Normal?Norms: What is Normal?

Understood rules for accepted and Understood rules for accepted and expected behaviorexpected behavior

Consist of the “proper behavior” within a Consist of the “proper behavior” within a groupgroup

So what the heck does normal mean, anyway?So what the heck does normal mean, anyway?

CollectivismCollectivism IndividualismIndividualism Giving priority to the Giving priority to the

goals of one’s group over goals of one’s group over one’s personal goalsone’s personal goals

Defining Defining one’s identity one’s identity in terms of the group’s in terms of the group’s identificationidentification rather than rather than personal attributespersonal attributes

See people as connected See people as connected to othersto others

Individual needs are Individual needs are sacrificed for the good of sacrificed for the good of the group.the group.

Giving priority to one’s Giving priority to one’s goals over the goals of goals over the goals of the groupthe group

Defining Defining one’s identity one’s identity in terms of personal in terms of personal attributesattributes rather than the rather than the group’s identificationgroup’s identification

Tend to see people as Tend to see people as separate and separate and independentindependent