MemoryWorking memory vs. long-term memoryI. Genetic diversityII. HeritabilityIII. Genes for X’IV. Separating H and E influenceV. Selective breedingVI. Twin researchVII. Adoption studiesVIII. Genes and child developmentIX. Environment and gene expression- Some differences in people are traceable to differences in their genomes. They may not be solely the result of differenting experiences and environments.- Gene expression can be influenced by environmental infuences, both internal and external.- There are no arrows leading from behavior to modification of genes themselves (compare to Lamarckism and inheritance of acquired characteristics- behavior does not affect genes)- 1.2% difference in humans and chimpanzees, but it makes all the difference. 1.2% of 3 billion base pairs- Meiosis: sexual reproduction creates genetic variability in offspringHeritability: population variation in a phenotype that is due to genetic variation (Vg), as opposed to variation due to environmental influences (Ve). If there is no genetic variation, heritability is zero.Total variation in a trait: Vtotal = Vg + VeHeritability = Vg/VtotalIf the heritability of height is estimated at 84%, this means that 84% of the difference of the two heights is estimated to be due to differences in the genes that contribute to heightHow can you separate genetic and environmental influences on phenotypic traits?Keep G constant, vary E; keep E constant, vary GPossibility that disposing genes lead to selection of an environmentFuller’s experiment: breeding for temperamentMating of F1 hybrids (fearful and friendly dog) produced offspring with a 3:1 ratio of fearful-nonfearful puppiesIdeas of artificial selection influenced Darwin’s ideas about natural selection, but natural selection works 7/24 timesExperiment: breeding of foxes can increase the frequency of genes that code for proteins and enzymes affecting adrenal hormones. Foxes became sweeter and less fearful of humans. Also became smarter.Tryon’s Experiment: Selective breeding of maze-learning ability in rats1) Test large sample of males and females for maze-learning ability. Identify maze-bright and maze-dull animals.2) Selective breeding: B x B, D x D (B= bright, D = dull)3) Look at distributions of errors in F1 animals.4) Repeat steps 2 and 3 with new generations.Tried to prove that genetic differences produced individual behavioral variations and contribute to behavior.Identical twins that don’t live together still have a stronger similarity than fraternal twins that live togetherBasic findings from adoption research:By young adulthood, the correlations of adopted children’s cognitive abilities and personalities with those of their adoptive parents are close to zero.Adopted children do not come to resemble the natural children of their adoptive parents, or other adopted children in the same family in these respects.Come to resemble their biological parents.The Colorado Adoption Project 1975-1982:245 living with birth parents, 245 living with adoptive parents“Scores of adopted children …had nothing whatsoever in common with the scores of adoptive parents: These children were no more similar in personality or intellectual skills to the people who reared them, fed them, clothed them, read to them, taught them and loved them all their lives than they were to any two adults taken at random off the street.”PSYC 100 1st Edition Lecture 12 Outline of Last Lecture  Memory- Working memory vs. long-term memoryLobes of the brain and their function Outline of Current Lecture I. Genetic diversity II. Heritability III. Genes for X’ IV. Separating H and E influence V. Selective breeding VI. Twin research VII. Adoption studies VIII. Genes and child development IX. Environment and gene expressionCurrent Lecture - Some differences in people are traceable to differences in their genomes. They may notbe solely the result of differenting experiences and environments.  - Gene expression can be influenced by environmental infuences, both internal and external.  - There are no arrows leading from behavior to modification of genes themselves (compare to Lamarckism and inheritance of acquired characteristics- behavior does not affect genes) - 1.2% difference in humans and chimpanzees, but it makes all the difference. 1.2% of 3 billion base pairs - Meiosis: sexual reproduction creates genetic variability in offspring Heritability: population variation in a phenotype that is due to genetic variation (Vg), as opposed to variation due to environmental influences (Ve). If there is no genetic variation, heritability is zero. Total variation in a trait: Vtotal = Vg + VeHeritability = Vg/Vtotal If the heritability of height is estimated at 84%, this means that 84% of the differenceof the two heights is estimated to be due to differences in the genes that contribute to height How can you separate genetic and environmental influences on phenotypic traits?Keep G constant, vary E; keep E constant, vary GPossibility that disposing genes lead to selection of an environmentFuller’s experiment: breeding for temperament- Mating of F1 hybrids (fearful and friendly dog) produced offspring with a 3:1 ratioof fearful-nonfearful puppiesIdeas of artificial selection influenced Darwin’s ideas about natural selection, but natural selection works 7/24 times Experiment: breeding of foxes can increase the frequency of genes that code for proteinsand enzymes affecting adrenal hormones. Foxes became sweeter and less fearful of humans. Also became smarter. Tryon’s Experiment: Selective breeding of maze-learning ability in rats1) Test large sample of males and females for maze-learning ability. Identify maze-bright and maze-dull animals.2) Selective breeding: B x B, D x D (B= bright, D = dull)3) Look at distributions of errors in F1 animals. 4) Repeat steps 2 and 3 with new generations. - Tried to prove that genetic differences produced individual behavioral variations and contribute to behavior. Identical twins that don’t live together still have a stronger similarity than fraternal twins that live together Basic findings from adoption research:By young adulthood, the correlations of adopted children’s cognitive abilities and personalities with those of their adoptive parents are close to zero.Adopted children do not come to resemble the natural children of their adoptive parents, or other adopted children in the same family in