1. Genetics, Evolutionary Psychology, and Behavior 3C

2. Behavior Genetics: Predicting Individual Differences
Behavior Geneticists - study our differences and weigh the relative effects of heredity and environment on behavior and personality.

3. Nurture and Human Diversity
Environment:
Parents
Prenatal
Experience
Peer Influence
Culture
Gender

4. Genes: Our Codes for Life
DNA (deoxyribonucleic) – complex molecule containing the genetic info that makes up the chromosome.
Chromosomes – threadlike structures made up of DNA molecules that contain genes
Any genetic basis for a trait are located in chromosomes
23 from mother and 23 from father
Located within bone cells

5. Genes: Our Codes for Life
Genes - small segments of DNA that are the biochemical units of heredity.
Capable of synthesizing a protein
One or more genes are responsible for expression or repression of a particular trait

6. Genome
Genome - set of complete instructions for making an organism, containing all the genes in that organism.
human genome makes us human
the genome for drosophila makes it a common house fly.

7. The threadlike structures that contain genes are called
Genomes
Synapses
Neurons
Chromosomes
Hormones 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

8. DNA is a complex Molecule Synapse Gene Genome Neuron 1 2 3 4 5 6 7 8 910 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

9. The biochemical units of heredity that make up the chromosomes are called
Genomes
Molecular genetics
Heredity
Behavior geneticists
genes 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

10. Studying the effects of heredity and environment on twins
Twin Biology
Studying the effects of heredity and environment on twins
Identical twins raised together - share the same portion of the chromosomes that determines a single trait or ____________
Identical twins raised apart – same genes, different environment
Fraternal twins – different genes, same environment

11. Identical Twins Studies
Twin Studies
Temperament, Intelligence
Abilities, Attitudes
Interests, Fears
Brain Waves, Heart Rate
Caution: any two strangers are likely to share coincidental similarities.

12. IdenticalTwins and IQ Bouchard Study
.69 Correlational coefficient for IQ tests of identical twins raised apart.
.88 raised together.

13. Twins and Personality
Temperament - a person’s stable emotional reactivity and intensity…part of your personality that you are born with.
Extroverted (outgoing) & fearless v. Introverted (shy) & cautious
Identical twins express similar temperaments

14. Separated Identical Twins and Personality
Identical Twins separated at birth – no extreme differences in personality
Differences between fraternal twins are greater than identical twins.
Twin Studies
Temperament, Intelligence
Abilities, Attitudes
Interests, Fears
Brain Waves, Heart Rate
Bob Sacha

15. Adoption Studies
Adoptees - Personalities are different from their adoptive parents and siblings.
Environment shared by a family’s children has relatively no impact on their personalities

16. Personality Big 5 Traits Extroversion – outgoing
Agreeableness - cooperative and compassionate
Conscientiousness – self-disciplined
Neuroticism – negative emotions
Openness – willingness to experience
new things

17. Twins Studies

18. Parental Influence Parents do influence: Attitudes Values Manners
Faith
politics

19. Heritability
Heritability refers to the extent to which the differences among people are attributable to genes
Heritability is numerical value with a range from 0.0 to 1.0
0 = genes do not contribute at all to individual differences
High environmentability
1.0 = genes are the only reason for individual differences
High heritability
For human behavior, almost all estimates of heritability are in the moderate range of .30 to .60.
Applies to populations not individuals
Two boys raised in a barrel with identical environmental conditions would have a heritability of ______?

21. Heritability and Big 5 Big 5 Traits Heritability Extroversion .67
Agreeableness .52
Conscientiousness .59
Neuroticism .48
Openness

22. Gene-Environment Interaction
Genes and environment affect our traits individually, but more important are their interactive effects.
Alessia Pierdomenico/Reuters/Corbis
Rex Features
People respond differently to
Rowan Atkinson (Mr. Bean) than Orlando bloom.

23. Twins Studies

24. The New Frontier: Molecular Genetics
Molecular genetics is a branch extension of behavior genetics that asks the question, “Do genes influence behavior?”
It seeks to identify the specific genes influencing behavior

25. Genetic predispositions
Studies of identical twins who had been reared apart most clearly highlight the importance of ________ in personality development.
Natural selection
Mutation
Adoptive relatives
Home environments
Genetic predispositions 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

26. Adoptive parents are most likely to influence the ________ of their adopted children.
Adult height
Political attitudes
Adult weight
Extraversion
personality 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

27. Heritability refers to the extent to which
Unrelated individuals share common genes
An obtain result occurred by chance
Nurture controls a trait rather than nature
Infant personality determines adult personality
Variation among individuals can be attributed to their differing genes 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

28. Molecular genetics seeks to
Identify specific genes influencing behavior
Assess the relative contributions of nature and nurture
Focus mainly on what makes us so much alike as humans
Treat individuals with mental disorders
Design machines that interact best with people 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

29. Evolutionary Psychology
Evolutionary psychology - studies the evolution of behavior and mind using principles of natural selection.
Adaptive behaviors are those that promote reproductive success .

30. Natural Selection
Natural selection - evolutionary process through which adaptive traits are passed on to ongoing generations because these traits help animals survive and reproduce.

31. Examples
Fear of Heights
Fear of the Dark
Fear of ostracism
Overeating

32. L.N. Trur, American Scientist (1999) 87: 160-169
Artificial Selection
Biologists like Belyaev and Trut (1999) were able to artificially rear and domesticate wild foxes, selecting them for friendly traits.
L.N. Trur, American Scientist (1999) 87:
Any trait that is favored naturally or artificially
spreads to future generations.

33. Question (summarized)
Human Sexuality
Gender Differences in Sexuality
Question (summarized)
Male
Female
Casual sex
60%
35%
Sex for affection
25%
48%
Think about sex everyday
54%
19%

34. Mating Preferences Females
Select one male because of the higher costs involved with pregnancy, nursing and childcare.
Look for maturity, dominance, affluence and boldness
Males
Mate with multiple females to spread genes
Look for youthful appearance and at ages associated with peak fertility.
If older wants younger women
IF teenager want women a few yrs. older

35. Criticisms of Evolutionary Psych
Works backwards to propose and explanation
Underestimates cultural expectations on human sexual behavior
Unethical and immoral men could use explanations to rationalize behavior toward women
Does not consider the importance of individual choices

36. Explain how an evolutionary psychologist might explain why humans developed into omnivores, eating both meat and plants.