Personality Psychology Lecture 15Outline of Last Lecture Temperament: Thomas and Chess- New York Longitudinal study- Easy temperament- Difficult temperament- Slow to warm up temperament Dimensions of Temperament: Buss and Plomin - Emotionality- Reactivity- Sociability Kagan - Inhibited- Uninhibited Biological Influences of Inhibition- Amygdala- Frontal Cortex- Stathmin proteinEvolutionary Psychology- Proximate causes- Ultimate causesEvolved Tendencies Contents of Human Nature: Buss- Need to belong- Helping and altruism Universal Emotions: Ekman- Mate preferencesParenthoodJealousyEagly and WoodOutline of Current Lecture Genetics and Personality - Behavior genetics- Heritability coefficient Selective breedingMolecular geneticsGene environment interactionsShared and nonshared environmentThese 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.BrainSES and serotoninCurrent LectureGenetics and Personality - Humans born with pair of 23 chromosomes, each chromosome has different genes that direct synthesis of proteins that guide developmento Genes don’t govern behavior directly but influence biological development of organism - Behavior genetics—study of genetic contributions to behavioro Estimate the degree to which variation in psychological characteristics is due to genetic factorso Interaction between genes and environment—not just genetics that dictate behavior- Heritability coefficient H2—statistic that refers to the proportion of observed variance in a groupof individuals that can be accounted for by genetic varianceo Refers to variation in population examined in given studyo Between (variance due to genetics) 0-1 (variance due to genetics)o Describes the degree to which genetic differences among individuals cause differences inan observed property (height, extraversion, optimism)o Highly consistent results o *Does NOT indicate degree to which genetics accounts for fact that particular person hasparticular characteristic  .8 doesn’t mean that 80% of behavior is because of genetics o Ex. h2=.4 for inhibition does NTO mean that 40% of that trait is inherited Means that genetics accounts for 40% of the variability between the people in the population studiedInvestigating Heritability - Selective breeding o Dogso Animals with desired trait mate them with animals that also have desired trait—if this is a heritable trait (related to genetics) then offspring should have that desired trait alsoo Produce animals with desired traito Cant do this with humans- Twin studieso Monozygotic (identical)—same genetic materialo Dizygotic (fraternal)—don’t have same genetic material Share same environment from beginning so might be more similarity between them still than with other siblings because of this- Adoption studieso How much are adopted children like adopted vs biological parentso *Relationship bweteen genetic similarity is greater, more similar to biological parents- People genetically identical but raised apart still have lots of similaritygenetics critical - If 2 people are different genetically BUT have same environment—any observed differences are probably genetics- Genetically identical twins do similar on IQ tests.8 correlation between degree of genetic similarity and IQ scoreMolecular Genetics- Examination of underlying biology - Look at genetic material of different individuals—look at genes linked to personality traits- Goal=show how genetic variation codes for differences in biology and in turn psychological aspects- Personality function=combination between genes and environmentGene-Environment Interactions- Nature AND nurture determine personality- Cooper and Zubeko Bred rats to be maze-dull (bad at mazes) OR maze-brighto Wanted to see how environment influenced problem solving in both kinds of ratso Raised some in enriched environments (fun things to do) and others in impoverished environments (not much to do, not stimulating)o enriched environment improved learning in maze-dull ratso impoverished environment handicapped maze-bright ratsShared and non-shared Environments- Shared environment—environmental influences that make siblings more alike- Non-shared environment—environments that create differences among siblings who grow up inthe same family o Especially with age differences in siblings the environment can be different for each - Study monozygotic and dizygotic twins- *Effects of environmental effects are negligible - Nonshared/unique experiences appear to be more important—friends, influence of peers, what you do outside of house- 40% of variability of personality trait is due to environmental factors- Observed differences in personality trait=40% genetics+0% shared environment+40% nonshared environment + 20% error (things cant account for, don’t know)Brain - Hemispheric dominance based on EEGo Left active during positive emotionso Right active during negative emotions - Serotonin—neurotransmitter important in mood regulation o Medications that increase availability in brainSSRIsSocioeconomic status of communities and Serotonin: Manuck- Found that those living in lower SES neighborhoods displayed lower serotonergic activity- Socioeconomic inequalities can affect even the neurobiology of their resident - Think serotonin influenced by environment (where they lived, how much money, etc)- Designed experiment so could examine directly possibility that those living in different kinds of neighborhoods would produce different levels of serotonino Had people take serotonin agonist (mimics action of neurotransmitter)o Lower levels serotonin=lower mood, vice versao Serotonin influences production of prolactin hormoneo Measured their blood samples to see how much prolactin they had in systemo individuals living in lower SES had less prolactin—also had lower levels thus of serotonin compared to people in higher