week-4-statistics-and-biological-approach.pdf

lOMoARcPSD|28762649 Week 4 - Statistics and Biological approach Personality Psychology (University of South Australia) Scan to open on Studocu Studocu is not sponsored or endorsed by any college or university...

lOMoARcPSD|28762649 Week 4 - Statistics and Biological approach Personality Psychology (University of South Australia) Scan to open on Studocu Studocu is not sponsored or endorsed by any college or university Downloaded by Alexia Jones ([email protected])  lOMoARcPSD|28762649 PERSONALITY PSYCH- WEEK 4: STATISTICS AND BIOLOGICAL APPROACH blaming actions on genetic makeup and ignoring Can’t make these distinctions at an individual level. Statistics and behaviour/ misrepresent logic) Concerns about renewed interest in eugenics Biological Knowledge is better than ignorance Misuse of language: “having a gene for…” finding HOW DO WE FIND OUT? (METHODS) approach that a personality trait has a genetic component does not mean the environment is powerless to modify the trait. We have genes that interact with FAMILY STUDIES - Similarity on trait dependent on degree of MODERATION AND MEDIATION the environment to produce things. genetic relatedness MODERATION: The effect of A on B varies - If a trait is highly heritable then family depending on levels of C AKA interactions/modifiers GOALS OF BEHAVIOURAL GENETICS members with greater genetic relatedness (e.g. 2x2 ANOVA) Function of a person’s personality- 1. Determine percentage individual should be more similar to one another moderating factor between behaviour and situation differences as a result of genes vs - Shared environment confounds this (similar MEDIATION: The effect of X on Y is a function of M/ environment (theoretical- can never 100% parenting style/ same school/ same causal pathways/ experimental condition- first separate genes from environment) nutrition) variable might lead to that last variable but only 2. How genes and environment interact - Bit shit for definitive evidence with the presence of the middle variable 3. Where environmental effects exist TWIN STUDIES - MZ vs DZ – estimates heritability y gauging HERITABILITY whether identicial and fraternal twins The proportion of phenotypic variance that is - Id MZ more similar han DZ  evidence of attributed to genotypic variance heritability - Cannot be applied to single an individual- - Assumptions: that twins have equal GENETICS AND PERSONALITY population level only. environments /representativeness - A small number of genes are different for - Not constant or immutable – something - Confounded bc: Their experiences can be different individuals may have a level of heritability but doesn’t different - These different genes include genes that always get passed on, or something may ADOPTION STUDIES indirectly code for physical traits and have happened that has never been seen - Between adopted kids and adopted parents personality traits - Not a precise statistic to provide evidence for environmental Behavioural geneticist attempt to determine the influence degree to which individual differences in personality ENVIRONMENTALITY - Genetic influence positive between are caused by genetic and environmental Proportion of observed variance in group of adopted children and biological parents differences. individuals attributable to environmental variance - Gets around equal environments Number of genes that are actually different are How much can the environment explain? assumption small. (ones for hair/eyes/personality) - Repressiveness? CONTROVERSIES NATURE-NURTURE: influence of genes and of - Selective placement of children combined ideological concerns (issue for political reasons- environment is only relevant for the discussion of with twins reared apart - still similar as group-level variation. adults Downloaded by Alexia Jones ([email protected])  lOMoARcPSD|28762649 PERSONALITY PSYCH- WEEK 4: STATISTICS AND BIOLOGICAL APPROACH - Differential responses of individuals with PHINEAS GAGE different genotypes to the same Known for improbablesurvival of an accident in environment – skin colour etc. which a large iron rod was driven through his head, GENOTYPE-ENVIRONMENT CORRELATION destroying much of his brain's left frontal lobe, and - Passive: parents provide both genes and for that injury's reported effects on his personality environment to children, yet children do and behaviour. WHAT DO WE KNOW? (RESULTS) nothing to obtain that environment e.g. First case to suggest the brain's role in determining PERSONALITY TRAITS number of books in the home personality and that damage to specific parts of the - Big 5: 20-50% heritability factor depending - Reactive: parents respond to children brain might induce specific personality changes- on trait. Imagination, neuroticism, differently depending on the child’s physiological evidence aggression pretty high. 54% genetics genotype e.g. cuddling- if kid likes cuddling - some studies say 40% of individual then parent might cuddle them more  PHYSIOLOGICAL MEASURES differences in personality is genetic evocation – evoking different responses in Electrodermal activity: ATTITUDES AND PREFERENCES parents and how they react - skin conductance - variable heritability - Active: person with a particular genotype - lie detector tests - traditionality – yes seeks out a particular environment e.g. - non-invasive, no discomfort - belief in god - no emigration- people higher on - disadvantage: movement is constrained - grit- yes openness/extraversion might travel more - can measure responses to various stimuli DRINKING AND SMOKING including sudden noises, emotionally - sensation seeking /extraversion/ charged pictures, pain anxiety, fear, guilt neuroticism - stable over time- show evidence of Physiology & cardiovascular activity: - blood pressure  stress reactivity heritability SHARED VS NON-SHARED ENVIRONMENTS Personality - HR increases with anxiety, fear, arousal, cognitive effort - Shared: features shared by siblings in family Brain activity environment  little impact PHYSIOLOGY- GALEN - Brain produces small amounts of electric - Non shared: features of the environment believed imbalance in blies causes personality activity that differ across siblings (friends/different inaccurate example of how biology is related to - What parts of the brain are lighting up and interests etc.)  most impact- things that personality is this in response of something related to help shape personality PHLEGMATIC: an abundance of phlegm made a personality? (pain) - Do not know WHICH differences are the person passive, calm and thoughtful - EEG most important MELANCHOLIC: an abundance of black bile made a - PET - Anywhere from 30-50% is heritable person unhappy, pessimistic and sombre - fMRI CHOLERIC: too much yellow bile made a person Others GENES AND ENVIRONMENTS unstable, aggressive and excitable - biochemical analyses of blood and saliva GENOTYPE-ENVIRONMENT INTERACTION SANGUINE: an abundance of blood makes a person - changes in hormonal levels happy, outgoing and lively Downloaded by Alexia Jones ([email protected])  lOMoARcPSD|28762649 PERSONALITY PSYCH- WEEK 4: STATISTICS AND BIOLOGICAL APPROACH - presence of woman elevates testosterone and physical risk taking in men Downloaded by Alexia Jones ([email protected])