PSY 213 Lecture 8 Outline of Previous Lecture I The life span perspective II The nature of development III Theories of development IV Research in life span development Outline of Current Lecture I The evolutionary perspective II Genetic foundations of development III The interaction of heredity and environment The nature nurture debate Current Lecture I The evolutionary perspective a Natural selection Evolutionary process by which those individuals of a species that are best adapted are the ones that survive and reproduce b Adaptive behavior Promotes an organism s survival in the natural habitat over time we learn to adapt to our environment c Evolutionary psychology i Emphasizes the importance of adaptation reproduction and survival of the fittest in shaping behavior ii Evolutionary developmental psychology 1 Interest has grown in using the concepts of evolutionary psychology to understand human development 2 Psychological mechanisms are domain specific something that was critical for survival in the past high fat foods now may contribute to tendency to crave fatty foods iii Evolution gave us biological potentialities but it does not dictate behavior iv People have used their biological capacities to produce diverse cultures v Aggressive and peace loving egalitarian and autocratic vi Studying specific genes in humans and other species and their links to traits and behaviors These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute II 1 Best approach for testing ideas coming out of evolutionary psychology Genetic foundations for development a Human life begins as a single cell b Nucleus of each cell contains chromosomes i Chromosomes Threadlike structures made up of deoxyribonucleic acid DNA ii DNA A complex double helix molecule that contains genetic information c Genes Units of hereditary information are short segments of DNA d Human genome consists of many genes that collaborate i Both with each other and with nongenetic factors inside and outside the body e Activity of genes is affected by their environment f Stress radiation and temperature can influence gene expression g Exposure to radiation changed the rate of DNA synthesis in cells damages cells h Mitosis Reproduction of cells i Meiosis Cell division that forms sperm and eggs gametes j Fertilization A stage in reproduction when an egg and a sperm fuse to create a single cell called a zygote k Zygote A single cell formed through fertilization l Sources of variability i Combining the genes of two parents in off spring increases genetic variability ii Important sources of variability iii Chromosomes in the zygote are not exact copies of those in the mother s ovaries and the father s testes iv DNA m Mutated gene Permanently altered segment of DNA n Genotype Genetic heritage Everything that makes you who you are o Susceptibility genes Make the individual more vulnerable to specific diseases or accelerated aging p Longevity genes Make the individual less vulnerable to certain diseases and more likely to live to an older age i Phenotype Way an individual s genotype is expressed in observed and measurable characteristics A person s observable characteristics eye color q Dominant and recessive genes principle III i One gene of a pair always exerts its effects dominant overriding the potential influence of the other gene recessive r Sex linked genes i When a mutated gene is carried on the X chromosome the result is called X linked inheritance s Polygenic inheritance i Polygenically determined by the interaction of many different genes t Gene gene interaction Studies that focus on the interdependence of two or more genes in Influencing characteristics behavior diseases and development u Sex linked chromosome abnormalities i Klinefelter syndrome Genetic disorder in which males have an extra X chromosome making them XXY instead of XY ii Fragile X syndrome Genetic disorder that results from an abnormality in the X chromosome which becomes constricted and often breaks iii Turner syndrome Chromosome disorder in females in which either an X chromosome is missing making the person XO instead of XX or part of one X chromosome is deleted iv XYY syndrome Chromosomal disorder in which the male has an extra Y chromosome v Gene linked abnormalities i Phenylketonuria PKU Metabolic disorder that left untreated causes mental retardation ii Sickle cell anemia Blood disorder that limits the body s oxygen supply Can cause joint swelling as well as heart and kidney failure iii Cystic fibrosis glands don t function properly Causes mucus to build up leading to breathing digestion problems iv Diabetes body doesn t produce enough insulin v Hemophilia delayed blood clotting Internal and external bleeding wont stop vi Huntington affects central nervous system and muscle motor coordination Not seen until age 35ish vii Spina bifida brain spinal chord abnormalities viii Tay sachs onset at 6 months Poor muscle tone blindness deafness uncontrolled convulsions Most die by age 4 The interaction of heredity and environment The nature nurture debate a Behavior genetics i Seeks to discover the influence of heredity and environment on individual differences in human traits and development ii Twin study Behavioral similarity of identical and fraternal twins is compared iii Adoption study Seek to discover whether in behavior and psychological characteristics adopted children are 1 More like their adoptive parents who provided a home environment 2 More like their biological parents who contributed their heredity b Hereditary environment correlation i Passive genotype environment correlations occur because biological parents who are genetically related to the child provide a rearing environment for the child ii Evocative genotype environment correlations occur because a child s characteristics elicit certain types of environments the child being good at something leads to invitations to environments that nourish that skill iii Active niche picking genotype environment correlations occur when children seek out environments that they find compatible and stimulating 1 Niche picking Refers to finding a setting that is suited to one s abilities You seek out experiences because they interest you youre good at them iv Epigenetic view Development is the result of an ongoing bidirectional interchange between heredity and environment