Nature and Nurture in Psychology

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Nature and Nurture in Psychology

• Module 3, Chapter 1

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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?

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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.

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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?

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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.

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Genes Chromosomes Location
Composition
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Genome Nucleotides

• The complete genetic instructions for a given
  organism
• All the genetic material in an organisms
  chromosome pattern

• The four letter code to distinguish genes
• Letters A,T,C, or G are used

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Mutation Genetic Predisposition

• Random errors in the replication of genes from
  parent to child which result in change of an
  individuals 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.

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Nature and Similarity

• Similarities
• 99 of all humans genetic make up is the same!
• Despite our differences, human beings throughout
  the world share a number of similaritieshow 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
• Darwins 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.

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Nature and Individual Differences Twin Studies

• Anyone know any twins?
• How are they alike
• and how are they different?

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Identical Twins Fraternal Twins

• Natures 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

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Heritability

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

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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.).

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Adoption Studies

• Compare adopted childrens 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

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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.

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Early Brain Development

• Use it or lose it!
• Experience nurtures nature (????)
• Ex I dont 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
  dont again until you are 21you 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.

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Look at how much nurture can affectExamples
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.

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What are Feral Children?

• How did their environment impact them?
• How about their nature?

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Environment MattersPeer 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 doesnt do drugs
  you probably wont 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.

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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?

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Collectivism Individualism

• Giving priority to the goals of ones group over
  ones personal goals
• Defining ones identity in terms of the groups
  identification rather than personal attributes
• See people as connected to others
• Individual needs are sacrificed for the good of
  the group.

• Giving priority to ones goals over the goals of
  the group
• Defining ones identity in terms of personal
  attributes rather than the groups identification
• Tend to see people as separate and independent