1. 1 Genetics, and Evolutionary Psychology 3C

2. 2 Genetics: Predicting Individual Differences Heredity – transmission of physical and psychological characteristics from parents to children through genes Behavior Geneticists - study our differences and weigh the relative effects of heredity and environment on behavior and personality.

3. 3 Nurture and Human Diversity ParentsPrenatalExperience Peer InfluenceCultureGender Some Environmental Influences:

4. 4 Genes: Our Codes for Life 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 in every cell nucleus DNA (deoxyribonucleic acid) – complex molecule containing the genetic info that makes up the chromosome. Nucleotide – a group of molecules that form the basic building blocks of DNA 4 types Adenine and guanine Cytosine and thymine

5. 5 Genes: Our Codes for Life Genes - small segments of DNA that are the biochemical units of heredity. Dominant – gene features appear each time gene is present Recessive – features only appear with another recessive gene active - expressed inactive - not expressed or dormant (may be expressed later in a persons life) Environmental events “turn on” genes to create protein molecules Self-regulating – genes react to the environment African butterfly is green in summer, is brown in fall Depression gene – responds to stress and codes for a protein that controls serotonin

6. Genes Alleles – two or more variations of a gene Can result in different observable Phenotype traits Example: Different eye colors Genotypic traits – set of genes responsible for a specific trait. Example: gene(s) responsible for eye color, baldness, schizophrenia Phenotypic traits – visibly expressed traits –Example: Blue eyes 6

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8. 8 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.

9. Mutation Mutation – a random error in gene replication that provides the source of genetic diversity –Nature chooses to pass on those that are most advantageous to survival 9

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11. The threadlike structures that contain genes are called 11 1.Genomes 2.Synapses 3.Neurons 4.Chromosomes 5.Hormones Table

12. DNA is a complex 12 1.Molecule 2.Synapse 3.Gene 4.Genome 5.Neuron Table

13. The biochemical units of heredity that make up the chromosomes are called 13 1.Genomes 2.Molecular genetics 3.Heredity 4.Behavior geneticists 5.genes Table

14. Twins Biology Monozygotic (identical twins) – one egg and one sperm Dizygotic (fraternal twins) – two eggs, two sperm 14

15. 15 Twin Biology Studying the effects of heredity and environment on twins 1.Identical twins raised together - share the same portion of the chromosomes that determines a single trait or ____________ 1.Identical twins raised apart – same genes, different environment 1.Fraternal twins – different genes, same environment

16. 16 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.

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

18. 18 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

19. 19 Separated Identical Twins and Personality Identical Twins separated at birth – no extreme differences in personality Differences between fraternal twins are greater than identical twins. Bob Sacha Twin Studies Temperament, Intelligence Abilities, Attitudes Interests, Fears Brain Waves, Heart Rate

20. 20 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

21. Personality Big 5 Traits –Extroversion – outgoing –Agreeableness - cooperative and compassionate –Conscientiousness – self-disciplined –Neuroticism – negative emotions –Openness – willingness to experience new things 21

22. Twins Studies 22

23. Parental Influence Parents do influence: –Attitudes –Values –Manners –Faith –politics 23

24. 24 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 100% Genet ics (Natu re) 90% Gen. 80% Gen. 70% Gen. 60% Gen. 50-50 60% Env. 70% Env. 80% Env. 90 % Env. 100% Enviro n. (Nurtu re)

25. 25 Two boys raised in a barrel with identical environmental conditions would have a heritability of ______?

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27. 27 Gene-Environment Interaction Genes and environment affect our traits individually, but more important are their interactive effects. Genes are self regulating - genes react to the environment Depression People respond differently to Rowan Atkinson (Mr. Bean) than Orlando bloom. Rex Features Alessia Pierdomenico/Reuters/Corbis

28. 28 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

29. Studies of identical twins who had been reared apart most clearly highlight the importance of ________ in personality development. 29 1.Natural selection 2.Mutation 3.Adoptive relatives 4.Home environments 5.Genetic predispositions

30. Adoptive parents are most likely to influence the ________ of their adopted children. 30 1.Adult height 2.Political attitudes 3.Adult weight 4.Extraversion 5.personality

31. Heritability refers to the extent to which 31 1.Unrelated individuals share common genes 2.An obtain result occurred by chance 3.Nurture controls a trait rather than nature 4.Infant personality determines adult personality 5.Variation among individuals can be attributed to their differing genes

32. Molecular genetics seeks to 32 1.Identify specific genes influencing behavior 2.Assess the relative contributions of nature and nurture 3.Focus mainly on what makes us so much alike as humans 4.Treat individuals with mental disorders 5.Design machines that interact best with people

33. 33 Evolutionary Psychology. Evolutionary psychology - studies the evolution of behavior and mind using principles of natural selection. Adaptive behaviors are those that promote reproductive success

34. 34 Natural Selection Natural selection - evolutionary process through which adaptive traits are passed on to ongoing generations because these traits help animals survive and reproduce.

35. Examples Human’s are omnivores Pregnant Women Avoid Strongly Flavored foods Children are more valued by biological father than step father 35

36. 36 Artificial Selection Artificial Selection - process by which humans breed other animals and plants for particular traits. Belyaev and Trut (1999) - artificially reared and domesticated wild foxes, selecting them for friendly traits. Any trait that is favored naturally or artificially spreads to future generations.

37. 37 Human Sexuality Gender Differences in Sexuality Question (summarized)MaleFemale Casual sex60%35% Sex for affection25%48% Think about sex everyday54%19%

38. 38 Mating Preferences Males Mate with multiple females to spread genes Look for youthful appearance and at ages associated with peak fertility. If older then wants younger women IF teenager then want women a few yrs. older Females Select one male because of the higher costs involved with pregnancy, nursing and childcare. Look for maturity, dominance, affluence and boldness

39. 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 39

40. Explain how an evolutionary psychologist might explain why humans developed into omnivores, eating both meat and plants. 40