The Nature and Nurture

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• Chapter 3
• The Nature and Nurture
• Of Behavior

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Genes Our Biological Blueprint

• Chromosomes
• threadlike structures made of DNA that contain
  the genes
• DNA (deoxyribonucleic acid)
• complex molecule containing the genetic
  information that makes up the chromosomes
• has two strands-forming a double helix--held
  together by bonds between pairs of nucleotides

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Genes Our Biological Blueprint

• Genes
• biochemical units of heredity that make up the
  chromosomes
• a segment of DNA capable of synthesizing a
  protein
• Genome
• the complete instructions for making an organism
• consisting of all the genetic material in its
  chromosomes

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Genes Their Location and Composition
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Evolutionary Psychology

• Natural Selection
• the principle that, among the range of inherited
  trait variations, those that lead to increased
  reproduction and survival will most likely be
  passed on to succeeding generations
• Mutations
• random errors in gene replication that lead to a
  change in the sequence of nucleotides
• the source of all genetic diversity

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Evolutionary Psychology

• Evolutionary Psychology
• the study of the evolution of behavior and the
  mind, using the principles of natural selection
• Gender
• in psychology, the characteristics, whether
  biologically or socially influenced, by which
  people define male and female

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Evolutionary Psychology

• Men preferred attractive physical features
  suggesting youth and health
• Women preferred resources and social status

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Behavior Genetics

• Behavior Genetics
• study of the relative power and limits of genetic
  and environmental influences on behavior
• Environment
• every nongenetic influence, from prenatal
  nutrition to the people and things around us

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Behavior Genetics

• Identical Twins
• develop from a single fertilized egg that splits
  in two, creating two genetically identical
  organisms
• Fraternal Twins
• develop from separate eggs
• genetically no closer than brothers and sisters,
  but they share the fetal environment

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Behavior Genetics

• Temperament
• a persons characteristic emotional reactivity
  and intensity
• Heritability
• the proportion of variation among individuals
  that we can attribute to genes
• may vary, depending on the range of populations
  and environments studied

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Behavior Genetics

• Interaction
• the dependence of the effect of one factor (such
  as environment) on another factor (such as
  heredity)
• Molecular Genetics
• the subfield of biology that studies the
  molecular structure and function of genes

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Environmental Influence

• Two placental arrangements in identical twins

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Environmental Influence

• Experience affects brain development

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Environmental Influence

• A trained brain

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Environmental Influence

• Culture
• the enduring behaviors, ideas, attitudes, and
  traditions shared by a large group of people and
  transmitted from one generation to the next
• Norm
• an understood rule for accepted and expected
  behavior

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Environmental Influence

• Personal Space
• the buffer zone we like to maintain around our
  bodies
• Memes
• self-replicating ideas, fashions, and innovations
  passed from person to person

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The Nature and Nurture of Gender

• X Chromosome
• the sex chromosome found in both men and women
• females have two males have one
• an X chromosome from each parent produces a
  female child
• Y Chromosome
• the sex chromosome found only in men
• when paired with an X chromosome from the mother,
  it produces a male child

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The Nature and Nurture of Gender

• Testosterone
• the most important of the male sex hormones
• both males and females have it
• additional testosterone in males stimulates
• growth of male sex organs in the fetus
• development of male sex characteristics during
  puberty
• Role
• a set of expectations (norms) about a social
  position
• defining how those in the position ought to behave

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The Nature and Nurture of Gender

• Gender Role
• a set of expected behaviors for males and females
• Gender Identity
• ones sense of being male or female
• Gender-typing
• the acquisition of a traditional masculine or
  feminine role

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The Nature and Nurture of Gender

• Gender and Culture

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The Nature and Nurture of Gender
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The Nature and Nurture of Gender

• Social Learning Theory
• theory that we learn social behavior by observing
  and imitating and by being rewarded or punished
• Gender Schema Theory
• theory that children learn from their cultures a
  concept of what it means to be male and female
  and that they adjust their behavior accordingly

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The Nature and Nurture of Gender

• Two theories of gender typing