This document provides an overview of genetics and evolutionary psychology. It discusses key concepts such as: 1. Genes and heredity, including DNA, chromosomes, genetic transmission, and genetic influences on behavior. 2. Natural selection and evolution, including evolutionary causes of behavior and criticisms of evolutionary psychology. 3. The genetics and evolution of behavior, including heritability estimates, twin studies, and how evolutionary psychologists study the impact of genetics on traits and behaviors. It explores topics like intelligence, sexuality, parenting, and more from an evolutionary perspective. The document aims to explain genetic and evolutionary roots and influences on human behavior.

1. Genetic Roots of Behavior
Meghan Fraley, PhD
Skyline College, Summer 2015

2. Memory Review

3. If you could wave a magic wand that would
eliminate your ability to forget, would you do it?

4. Should we allow eyewitness
testimony? Why or why not?

5. Genetic and Evolutionary
Psychology

6. Overview of Genetic and
Evolutionary Roots of Behavior
Genetics
• Parts of Cell
• Gene Transmission
Natural
Selection
• Naturalistic
Fallacy
The Genetics
and Evolution
of Behavior
• Heritability
Estimate

7. Heredity Crash Course

8. I. Genetics

9. Genes

10. Genes & DNA- Parts of a Cell

11. Genetic and Environmental Influences
 Heredity: Inborn genetic endowment
 Genetic and environmental variables
transact continually over time
 Weight of genetic/environment changes
over time (personality/IQ)
 Environment more significant in early
years.
 As people age, more diverse in their
patterns
 Penetrance is a term used in genetics that
describes the extent to which the
properties controlled by a gene, its
phenotype, will be expressed. Penetrance
is the percentage of individuals given a
specific genotype which actually express
an associated phenotype. More…

12. The Secrets of Genes
 Genes - are the basic units of heredity located
on chromosomes which contain threadlike
strands of DNA.
 Egg and Sperm contain 23 chromosomes each.

13. What are chromosomes?
 Humans have 23 pairs of
chromosomes, with one
chromosome from each
parent.
 The chromosomes are
coiled up DNA.
 Under normal conditions
all of the chromosomes
are inherited in tact.

14. How Genes Interact! Mendel’s
Little Peas
Gregor Mendel- Basic laws of genetic inheritance
Mendel's Laws are as follows:
• 1. the Law of Dominance
• 2. the Law of Segregation
• 3. the Law of Independent Assortment

15. Types of
Chromosomes

16. Chromosomal Disorders
Chromosomal
deletion:
• when cells go
through
meiosis,
portions of the
chromosome
are lost.
Chromosomal
inversion:
• when cells go
through
meiosis, parts
of the
chromosome
are flipped.
Chromosomal
translocation:
• when cells go
through
meiosis, parts
of the
chromosomes
stick together
and switch.
Chromosomal
non-disjunction:
• when cells go
through
meiosis the
chromosomes
don’t separate
correctly and
either too
many or not
enough are
passed on.

17. Heredity
 Genotype and Phenotype

18. Genetic and Chromosomal
Abnormalities
 Klinefelter’s
Syndrome
 Turner’s Syndrome
 Down’s Syndrome
 PKU
 Hemophilia
 Sickle Cell Anemia

19. Influences on Development
 Genotype versus Phenotype
 Genotype: Set of genes
 Phenotype: What is observable
 Polygenic (many-genes):
 most traits are influenced by
multiple genes
 RNA has significant role in
memory
 Chromosomal Defects
 Down syndrome
 More susceptible to alzheimer’s,
leukemia, and heart disease
 Klinefelter syndrome (XXY)
 Turner syndrome (X): short,
drooping eyelids, webbed neck

20. II. Evolution by Natural
Selection

21. Focus: Proximate to Ultimate
Causes
Proximate:
Within the
lifetime
Ultimate: Why
change has
occurred over
years

22. What is Evolution?
Changes that occur in a
population over time

23. Theory of Evolution

24. The Principles of Natural
Selection
 Natural Selection
 Natural variations
 Less beneficial
characteristics don’t
survive
 Next generation has more
people with the beneficial,
and less with the
detrimental characteristics
 Evolution: Changes that
occur in a population over
time

25. Myths & Misconceptions about
Evolution

26. Evolution Misconceptions
Naturalistic Fallacy
 The idea that anything
“natural” is “good” or the
more recent traits are
“better”
 The process of evolution
has no foresight
 Discuss: Where do you see
the naturalistic fallacy
referenced?
“Survival of the
Fittest”
 Why is this not entirely
accurate?

27. III. The Genetics &
Evolution of Behavior

28. The Genetics of Behavior
 Both genes and environment
interact to shape human
behavior.
 The fundamental issue is
how much a role genetics
do play in shaping human
behaviors.
 Examples: psychological
disorders, weight gain,
personality, sexual
orientation?

29. The Genetics of Behavior
Both genes and environment
interact to shape human behavior.
The fundamental issue is how
much a role genetics do play in
shaping human behaviors.
• Examples: psychological disorders, weight
gain, personality, sexual orientation?

30. Heritability
The proportion of
variation among
individuals that we
can attribute to
genes.
It is a
mathematical
formula.
Heritability: Determining the
Impact of Genes
Behaviors have
a genetic
component
Behaviors have
an
environmental
component.

31. Heritability Estimate
 The contribution to an
observed characteristic is
expressed in terms of a
heritability estimate.
 Indicates the extent to
which the phenotype varies
within a group of people
 We use twin studies to
examine the genetic
influence
 Penetrance describes the
extent to the phenotype
will be expressed.

32. Determining Heritability
Sibling Studies!
•Twin Studies
•Adopted Children & their
Bio Sibs
How do
Evolutionary
Psychologists
Attempt to
Determine the
Impact of
Genetics?
Compare
monozygotic and
fraternal twins
to infer how
much of a genetic
component exists
for a particular
behavior.
Study adopted
children and their
resemblance to
their biological
parents
to infer the
influence of
heredity.

33. Twin Studies

34. Twin Studies: The results
 To summarize the countless amount of studies: twins
(especially identical), whether or not they are raised in
the same environment are very much alike in many
ways.

35. What is Evolutionary
Psychology?
Goal: Understand how human
behavior as impacted by the
passing on of genes by…
Reconstructing problems of ancestors
Establishing common roots of behavior
and how they manifest today

36. Evolutionary Psychology: A Brief
Overview

37. Think like an Evolutionary
Psychologist
 Why do infants fear strangers
when they become mobile?
 Why are most parents
devoted to their children?
 Why do we divide people
into categories?
 Why do we have more
phobias about spiders and
snakes than electricity and
nuclear weapons?

38. Break: Discuss ideas you have
about how our behavior now
is influenced by our ancestors

39. Genetics & Evolutionary
Psychology Applied
Intelligence and Sexuality

40. Think like an Evolutionary
Psychologist, Revisited
 Why do infants fear strangers
when they become mobile?
 Why are most parents
devoted to their children?
 Why do we divide people
into categories?
 Why do we have more
phobias about spiders and
snakes than electricity and
nuclear weapons?

41. Evolutionary Psychology, What do
you think?
Critiquing the
Evolutionary Perspective
 Evolutionary psychologists
take a behavior and work
backward to explain it in
terms of natural selection.
 Evolutionary psychology
proposes genetic
determinism and undercuts
morality in establishing
society.
 Where genders are unequal,
gender preferences are
wide, but closely equal,
preferences narrow down.
Evolutionary
Psychologists Reply
 Evolutionary psychologists
argue that we need to test
behaviors that expound
evolutionary principles.
 Evolutionary psychologists
remind us how we have
adapted, but does not
dictate how we ought to be.
 Males and females are more
alike than different, if we
study these differences we
can establish their causes.

42. Discussion the Impact of Low SES
on Intelligence
 Genes have a weaker effect
on intelligence without
adequate health care,
stimulation, and
nourishment.
 Potential may not ever be
realized

43. Love & Lust: Sexuality, the Brain,
& Evolutionary Psychology
Types of Mating Systems
Attitudes toward Mating
Humans & Other Mammals
Jealousy between the
Genders & Evolutionary
Perspective
Describe the Differences in
the way human males and
females view paternity

44. Why are genes not everything?
 Not all traits are equally heritable or
unaffected by shared environments
 Some studies may underestimate the impact
of the environment
 Even traits that are highly heritable are not
rigidly fixed and can be modified by
experience.

45. Genetics & Evolution Review:
Concepts to Know
Structure of DNA
Natural Selection
• Ultimate & Proximal Cause
The scientific study of evolution
Intelligence & Genetics
Genes, Sex, and Mating Behavior

46. Genetic Assignments
• Main Concepts in Genetic & Biological Psychology
Review:
• Can Your Genes Predict Whether You’ll be a Conservative or a
Liberal? –The Atlantic
Read:
• What are characteristics you think you learned from your
family? What are personality characteristics that you think
might in the genetic makeup?
Journal:
Forum: Post on forum on at least one critical
thinking question