Transcript Introduction to Psychology

Chapter 3
The Nature and Nurture
Of Behavior
Evolutionary Psychology
Video Clip
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http://www.pbs.org/w
gbh/evolution/library/
01/6/l_016_08.html
Sweaty T-Shirts and
Human Mate Choice:
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Subtle chemical signals, or pheromones, have long
been known to draw pairs together within the same
species, and for a specific reason.
In mice, for example, experiments showed that
pheromones acted as attractants between males and
females who were genetically similar except that
they differed in a certain type of immune system
gene.
That difference is actually a survival benefit: The
combination of two individuals' different MHC (major
histocompatibility locus) genes gives their offspring
an advantage in beating back disease organisms.
William James,
Principles of
Psychology (1890)
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It takes...a mind debauched by learning to carry
[out] the process of making the natural seem
strange…Why do we smile, when pleased, and
not scowl? Why are we unable to talk to a crowd
as we talk to a single friend? Why does a
particular maiden turn our wits so upside-down?
The common man can only say, of course we
smile, of course our heart palpitates at the sight of
the crowd, of course we love the maiden, that
beautiful soul clad in that perfect form, so palpably
and flagrantly made for all eternity to be loved!
Basic Tenets of
Evolutionary Psychology
Our neural circuits were designed by natural
selection to solve problems. Different neural
circuits are specialized for solving different
adaptive problems.
 Consciousness is just the tip of the iceberg;
most of what goes on in your mind is hidden.
 Our modern skulls house a stone age mind,
adapted to the environment of evolutionary
ancestry (EEA).
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Genes: Our Biological
Blueprint
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Chromosomes
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threadlike structures made of DNA that
contain the genes
DNA (deoxyribonucleic acid)
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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
Genes: Our
Biological Blueprint
 Genes
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biochemical units of heredity that make up the
chromosomes
a segment of DNA capable of synthesizing a
protein (protein is the building block of life)
 Genome
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the complete instructions for making an
organism
consisting of all the genetic material in its
chromosomes
DNA & RNA
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DNA: Deoxyribonucleic acid. One of
two types of molecules that encode
genetic information. The other is
RNA.
In humans DNA is the genetic
material; RNA is transcribed from it.
In some other organisms, RNA is
the genetic material and, in reverse
fashion, the DNA is transcribed from
it.
DNA & RNA
 DNA
is a double-stranded molecule held
together by weak hydrogen bonds
between base pairs of nucleotides. The
molecule forms a double helix in which two
strands of DNA spiral about one other.
 The double helix looks something like an
immensely long ladder twisted into a helix,
or coil. The sides of the "ladder" are
formed by a backbone of sugar and
phosphate molecules, and the "rungs"
consist of nucleotide bases joined weakly
in the middle by the hydrogen bonds.
Nucleotide
Nucleotide: A subunit of DNA or
RNA. To form a DNA or RNA
molecule, thousands of nucleotides
are joined in a long chain
 There are four nucleotides in DNA.
Each nucleotide contains a base:
adenine (A), guanine (G), cytosine
(C), or thymine (T).
 Base pairs form naturally only
between A and T and between G and
C.
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Genetics and
Behavior
Nucleus
Cell
Chromosome
Gene
DNA
Evolutionary
Psychology
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Natural Selection
 the principle that, among the range of inherited
trait variations, those contributing to 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
Evolutionary
Psychology
 Evolutionary
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Psychology
the study of the evolution of
behavior using the principles of
natural selection
 Gender
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in psychology, the
characteristics, where
biologically or socially
influenced, by which people
define male and female
Evolutionary
Psychology
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Men everywhere preferred attractive physical
features suggesting youth and health
For males, a question: Which
woman is more attractive?
For females, a question: Which
man is more attractive?
Monopolizing &
Mutilating Women
Techniques across cultures: veiling,
chaperoning, purdah, foot binding
 “Less familiar to Westerners but more frequent
are genital mutilations designed to destroy the
sexual interest of young women and even their
penetrability until surgically reopened…Such
genital mutilations are still prevalent in 23
countries.” (Hicks 1986)
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