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Final Lecture Notes for PSYB30

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Dwayne Pare

Lecture 6: Personality and Genetics Cell Biology Basics  Cell nucleus contains DNA  DNA carries genetic information for all living things  Controls growth and development. It determines what someone is going to be looking at (tall, short) and blueprint for various aspects of your development  DNA controls everything that person is not going to be learning  DNA is organized into chromosomes. DNA has 23 pairs of chromosomes.  All chromosomes together has all the DNA  The ordering of bases that constitutes a genetic code. The ordering of the letters will be different for humans and a chick pea, cat or a panda bear.  The rung in a DNA is made up of 2 bases.  The relationship between DNA and a gene - A gene is a 100 to several million rungs on the ladder that’s what constitutes one gene. It is a segment of a DNA  Genotype (it is a gene) - Is your actual genetic makeup - Specific genetic makeup - Genome: the exact order of bases on your entire DNA, then that would be your entire genome, which would correspond to your genotype. - Genotype is made up of all of the different alleles that you have. - Allele: is a gene variance. - You don’t see everything in your genetype  Phenotype (‘the other thing”) - How genetic makeup is expressed - Recessive and Dominant alleles - More than one gene is responsible for eye colour  Gregor Mendel - Father of genetics - Did experiment on peas (texture, wrinkles) - He cross-pollinated different plants, and then he discovered that some of the characteristics of the pea would not show up in the next generation, but will show in the next generation – that’s how he came up with dominant and recessive traits. Forms of gene expression  Dominant- Recessive - There are two alleles and one of them dominates and another is recessive - Also refers to Mendalian inheritance - He actually experimented with mice  Co-dominance and incomplete-dominance - There are two alleles where neither one of them is dominant, or only one of them is dominant, but does not hide the effects of the other one. - Co-dominance: is when both of the genes are expressed in a living creature (both traits are expressed. For example, you have black cow and white cow and the offspring turned out to be white and black. - Two alleles in that combination of the two that are expressed. For example, you have black cow and white cow and offspring turned out to be grey. Another example, you have a red flower and a white flower and the offspring ends up being pink flower. - Example of co-dominance in people is blood type. A and B allele is dominant, but the O allele is recessive. So if you get an A allele from one parent and B allele from another parent, then the blood type is going to be AB. If you get A allele from one parent and O allele from another parents, then your blood type would be A because OO type is recessive.  Polygenic - Personality traits are all polygenic - 1+ allele - Controls a particular trait or responsible for that trait - Many pairs of alleles create expression - Skin color is polygenic Role of Environment  Phenotype - Consists of the independent effects of the genotype and the environment 1. Genotype-Environment interaction - Textbook talks about depression and maternal rejection, what the research has found are that you need to have both factors in order for the particular outcome to happen. Genes that predispose you to the depression and you also have to have the lack of maternal support. - Diathesis stress model: one that has genetic predisposition to develop a certain trait or certain psychological disorder, but then something has to happen in the environment in order for that trait to actually express in that person. There is a lot of interesting research taking place in abnormal psyche and personality psyche. - Impact of environment depends on genotype. Two people can encounter same environment, but different will express that trait differently because environment’s interaction with the genotype. - Example, religious upbringing reduces influence of genetic factors on disinhibition (= doing wild stuff – partying, sexual risk taking). For this particular study, they looked at people who could be argued to be similar or different in terms of their genotypes and disinhibition, and separated them depending whether they had religious upbringing or not. And what they found was that if you had the genetic makeup/genotype for disinhibition that would encourage the disinhibition and if you had religious upbringing this would not be fostered. So, this was only the people who did not have the religious upbringing this aspect of the genotype was actually expressed. People who had religious upbringing were more likely to be inhibited, but it wasn’t strictly environmental, it had to do with the interaction between genes and the environments. - Interaction means that the impact of the environment depends on the person’s genotype 2. Genotype-Environment Correlation - Differential exposure of individuals with different genotypes to different environment - Correlation means it is harder to separate the genotype and the environment. Here, people are exposed to different types of environments depending on their genotype. I. Passive manner: parents provide both genes and environment to children. It is passive because the child does not play a role. Example, child’s verbal ability and the number of books in the home. Passive decreases with age II. Reactive/ evocative: Parents (or others) respond to children depending on the genotype. People respond differently depending on their phenotype. Example, Baby’s liking for cuddling and mother’s cuddling behaviour that is parents are going to evoke that behaviour. III. Active: person with particular genotype seeks the environment. Infant gets old enough to choose the environment. Example, high sensation seekers expose themselves to risky environments. Active increases with age because people are more mobile around their environment. - Positive correlation means that someone has that particular genotype and they wind up being exposed to their environment that increase their likelihood that genotype is going to express for that particular trait or behaviour. It can be other way around, if someone has particular genotype they can wind up being exposed to an environment that discourages that expression of that genotype. And if that’s the case then you are less likely to see it in the phenotype. Behavioural genetics  Attempt to determine % of individual differences in a trait is due to genetics and environment  Most common area of research is intelligence.  99.9% of behavioural factors in people some combination of genetic and environmental.  Determine the ways genes and environment interacts and correlates.  The outcome they are interested in personality is the outcome that cause particular individual differences.  Determine what the relevant environmental factors are  Heritability - About of individual differences in traits due to genetic differences - It means that what amount of differences in individual can be traced back to genetic makeup. - Misconceptions about heritability o Only applies to group-level variation o At some point it may be possible to look at how much an individual’s behaviour is based on genetics and environment, but the technology is not at the point you could do that yet o It is not constant or immutable  If the environment is homogenous then you could have a closer match between genotypes and phenotypes, and the rate of heritability will be higher.  As environmental variations increases, then you are going to see less genotype on phenotype.  Even highly heritable traits can be modified by the environment.  If heritability for this particular trait is 70% that means that all of these people of their trait X is genetic factors and other is due to environmental. Actually, that’s not the case, it depends other things as well.  Heritability is not a precise statistic – think estimate. You are going to see range of heritability and not a precise number.  Environementality - Extent to which individual different are due to environmental differences. Behavioural genetics Methods  Look at a higher level of analysis. 1. Selective breeding: it can be done with dogs, mice and rats - Can only occur if a desired trait is highly heritable - Done using animals - Look for animals that exhibit a particular behaviour, and having its offspring exhibit 100% of that trait - Example, you could breed mice to be depressed – depending on the time that a mouse spends time struggling is a marker of depression. We can depress mice because they produce in large quantities. 2. Family studies - Can do with humans - Look at the degree of genetic overlap among family members with similarity in trait - Example, sensation seeking (do more risky things), and give it to all these people in your family, and look at genetically similar your family members are. - If trait is highly heritable, those more closely related should be more similar. - Problems  Members of a family share elements of the environment-confounds genetic with environmental influences.  Thus, family studies are never definitive 3. Twin Studies - Can do with humans - Estimate heritability by seeing of MZ twins are more similar than DZ twins - (Video) o Big Five was better research method o Dark Triad: interested in all of all variables at a sub-clinical level (would not be diagnosed as personality disorder) o Two important things I. Cluster of things that they hang together should also be considered separate from each other. She also said that they can make individual contribution to certain behaviour. Also, trying to find the correlation between dark triad and different traits in the big 5. What they found is that NEO-PI-R does not adequately capture traits in the big triads. She thinks that NEO-PI-R should be expanded or we need to add different questions to cover anti- social behaviour. She also talked about how much of the dark triad traits are influences of a non-shared environment. II. She talked about the twin studies: 2 different studies. Whether these factors in the dark triad where heritable, with that they found was that there was a modern influence of the genetics and also of the known shared environment (= environment of people who grew up together that is not the same – children went to different school). - Limitations o Two assumptions of the twin studies  Two halves of the environment are much the same (as twins from bigger – DZ & MZ – their environment is going to be different)  Representativeness - Twins are different in some systematic ways – often twins have a lower birth weight, and not carried to the end of the term. The results may not be able to generalize.  4. Adoption Studies - Can do with humans - Positive correlations on traits between adopted kids and parents – environmental influence. - You would expect that no genetic based correlation - If there is a strong correlation, then it is the result of the environment - Positive correlations between adopted children and genetic parents – genetic influence. - Assumption adopted children and their (adoptive and genetic) parents are representative questionnaire. - Problems of selective placement of adopted children o You are assuming that there is no corresponding between environment where the child would have been raised and the environment that the child winds up being raised in. Types of families that adopt children are going to be similar in certain ways and the geographic area that they are adopted, they are not going to send all the way to other country, it is most likely going to be a same geographic area. So the lot of environmental influences are going to be the same. o If there is a strong genetic correlation, it does not mean that it is because of genetics, it could be because of shared environmental components. - Design that combines strengths of twin and adoption studies = twins reared apart. Shared Environmental Influences  Aspect of family environmental generally same for all  Make people in the family similar to each other  Example, # of books, presence/absence of TV, quality and quantity of food, parents’ values/ attitudes, school, church.  If phenotype influenced solely by shared environment (MZ and DZ twins that not adopted, or both adopted by same parents) o MZ twins together: r= 1.00 o DZ twins together: r = 1.00 o Siblings together: r =1.00 Non-Shared Environmental influences  Example, treated differently by parents, different friends, different teachers, some goes to camp.  If trait influenced solely by non-shared environmental influences o MZ twins together or apart: r=1.00 o Same for DZ twins and for siblings Heritability of Traits  For each FFM factor 35%- 65% variability due to heritability  For most traits, environment has major influence, but influence is primarily from non-shared  For most traits, shared environments have little impact. Example: Intelligence  Texas Adoption study (large, well-controlled)  Time 1, children’s IQ significantly correlated with both biological mom (.23) and adoptive mom (.13). if there was no correlation of environment, then the child’s IQ and mother’s IQ is closer to 0.  Time 2, children’s IQ significantly correlated only with biological mother (.26). Looks like environment is not playing role. Time 2, children are older. Other Research on Intelligence  Near 0 correlations between biologically unrelated siblings  Twin data o MZ reared together : r =.76 o MZ reared apart: r=.77 o DZ reared together: r=.22 o DZ reared apart: r=.32 Intelligence and personality compared  Heritability higher for IQ than personality o Example, correlations for MZ twins are higher for IQ (.76) than personality  Shared family environment not an important influence on either IQ or personality Epigenetic  Study of heritable changes in gene function that occur without change in DNA sequence.  physical characteristics of identical twins diverge as they age Neuroscience and Personality [other biological theories] Relationship of personality and changes in:  bodily responses  brain structures (introvert/extravert)  brain activity  biochemical activity MAJOR DIVISIONS OF THE NS CNSBRAIN OR SPINAL CORD PNSSOMATIC NERVOUS(efferent or afferent nerves) AUTONOMIC(sympathetic or para-)  Sympathetic nervous system(try to help you-caveman age) -“fight-or-flight” system(physical or pshycho-,increase activity in those areas when you need to fight or flee)  Non-essential activities are dampened (GI/urinary) -Heart rate (increase-oxygen,breathing rapid and deep) -skin is cold and sweaty -pupils dilate(so cud see better) -blood diverted to skeletal muscles(enable more efficient movement) -liver releases more glucose into blood(so energy more efficient to use)  Parasympathetic is opposite  Bodily Responses: Measuring ANS activity  Heart rate  Body temp and blood flow (direction  Skin conductance (GSR) (measuring perspiration)  Electromyography (EMG) (measures non-visible muscle movements) Brain Structure Measures  Static differences in relative size and weight and cell numbers of brain parts  Computerized tomography (CT) scan  Magnetic resonance imaging (MRI) METHODS FOR MEASURING BRAIN STRUCTURE DURING STIMULI  PET-(w/low lvl of activity and w/glucose, the areas most active has the most glucose  CORTICAL STIMULI(electrodes to the brain, normally w/ animals)  TMS(newest type of tech,transcranial,magnetio stimulation,proved for treatment of depression)  EEG(measuring diff activity thru skull)  fMRI(activity,when brain active, looking at diff lvls of activity)Brain Activity Biochemical Activity Neurotransmitters: chemicals released by neurons to excite next neuron into action, or inhibit it(make sure msgs are passed along)  Dopamine(pleasure,learning,sensitivity to rewards)  Serotonin(w/mood regulation/arousal,eating, sleeping)(SSRI/SNRI-ensires tht the serotonin is active;y effective in the brain)  Norepinephrine and epinephrine are also considered stress hormones  increase blood flow to muscles by increasing heart rate and blood pressure  Research example Love-drive,below cortex (nurture and Nature) -timing and proximity,values/goals -dopamine(novelty seeking,creativity,unpredictable,impulsivity) -serotonin(explorers,religiosity,calm,orderly, good w/ #’s,close minded,must have loyal friends) Testosterone(anylytical eg.structure of music; mechanics,experimental,REAL(least religious),impatient,emotional flooding) Estrogen/oxytocin(contextual,social,introspective,expressive,negotiator,keeps thinking Dopa/Sero=similarity attracts(explorers) Estro/Testo=opposite attracts(mechanics,expressive) Brain circuitry of personality, Summary: found 4 styles of thinking,did it by questionnaire w/traits tht go w/...MRI-neaural Important Biological Theories of Personality  Eysenck’s PEN model  Reinforcement Sensitivity Theory (RST)  Temperament Eysenck’s PEN model(biological/neurological theory)  Factors: Neuroticism, extraversion, psychoticism  Evidence:  Cross-cultural universality  Consistency over time  Heritability  Eysenck:  Introverts: greater cortical of arousal, spec in ARAS(ascending reticular activat sys);(need quiter enviro-to recover back from their homeostasis)  Should be present in sleep  Only difference in response to moderate stimulation (more arousable base on same stimuli comparison)  Eysenck:  Neuroticism = stability of SNS(sensitive nervous sys) and vulnerability of negative emotions  HN(high neurol;sensitive nervous sys): increase in heart rate in response to intense stimuli  I’s(introverts) do as well  HN, but not I: greater startle response to scary pictures  Overall, HN may be more sensitive to (-) emotions , but not arousing situations as I‘s are  Not sufficient support for Eysenck’s hypothesis that neuroticism is related to SNS activity Reinforcement Sensitivity Theory (RST) Gray’s (1972, 1990) reinterpretation of Eysenck’s theory Neurological Systems  Think: sets of neural networks (together to perform a fxn,effect)  Flight-fight-freeze system (FFFS)(organize our rxns to aversive stimuli)  Fearfulness(cautious), avoidance (phobias,paranoi)  Behavioral approach system (BAS)(organizes the appetitative-things we want)  Optimism, impulsiveness ;extraversion  Behavioral inhibition system (BIS)  Resolves conflicts (by weighing alternatives)  Anxiety before resolution (b4 stimuli may be aversive to the person-when activated the person may becme more anxious,worry,more sensitive to punishment);neurotic *FFFS,BAS,BIS all interrelated eg.increase in one effects increase in nother Table 7.4 in textbook Individual difference in relative sensitivity of systems(in textbook)  Reinforcement Sensitivity Theory Systems  Key Predictions of RST  Individual differences in reward sensitivity  Individual differences in learning Reward sensitivity example Prediction: Brains of high and low BAS people respond differently to food  This (in text) Evidence  Neural differences  BAS drive significantly accounted for signal differences in five brain areas related to visual food cues(more activating sys to food) (increased dopa, in ventral strat and pali,amgyd,orbitofron,midbrain)  Strongr rxn for appetizing/disgust food  Learning (bas by reward,bis by punishmnt Larsen et al., (2003). Colour naming task (moderate difficulty: average performance 50%)  • Condition 1: Start with $10, punished for incorrect or slow responses - all ended with $5  • Condition 2: Start with $0, rewarded for correct and fast responses - all ended with $5  • Those high in BAS did better in Condition 2(start w/ 0),  • Those high in BIS did better in Condition 1(start w/ 10,wont take the chance) The Zinbarg and Mohlman Study (1998) Results: RST prediction supported Temperaments (groups of collection of traits) biological theories converge on 3 temperaments temperament is common to all biological theories, it is separate but clustered Present Early/geneticstable across life spanmutable w/ maturation and experienceexpressed thru energy lvlsimilar in other species Three clusters of related personality traits:  Extraversion: (collection of traits based on othr bio theories)  + Emotion, reward sensitivity, sociability, social rewards, approach  Neuroticism:  Negative emotion, anxiety, punishment sensitivity, withdrawal  Impulsivity:  Psychoticism, sensation/ noveltyeeking, lack of constraint/conscientiousness/agreeableness  See table 7.2 in text (distinguish these traits w/othrs in othr theories-they are connected but separate;  This of notes, make sure to connect Neurological Correlates of Temperaments Overview(responsiveness to emotion eg. Emotion is the same,but stimuli not the same)  Difference between emotion expression and response to emotions  Extraverts: More (+) emotions(more + rxn to positive emotions;opp for N), stronger reactions than I  High N : more (-) emotions, stronger reactions than LN  Positive and negative emotions are separate dimensions, not opposites(cud have it both at the same time, or just +, no – emo, or none…like bittersweet) Correlations of Cortical Thickness(when sometimes an area is smaller,tht part of the brain is more efficient,cause synapses all removed;no one knows whoch part of the brain is the bigger part)  Introversion is correlated with thickness of three sections of the right (but not the left) cortex.  Could be a function of the lowered social inhibition of extraverts (why the area is thinner)  Keep in mind that more grey matter does not equal functionality  HN correlated with less volume in left cortex, compared to LN  What have we learned from the neuroscience of personality? The jury is still out!we still:  Need to think in terms of brain system, not just brain parts  Need to move beyond correlation methods Connectionism (communication pathways of the brain,spec. Networks,electrical activity to instruct ways to move-thru comp modelling  Central principle: mental phenomena can be described by interconnected networks of units  Neurons in the brain communicate with one another through elaborate networks  Connectionist networks (or artificial neural nets) are special computer programs that simulate biological networks  Mental processing seen as the dynamic(how they are interconnected) and evolving(not static,looking at things as they move)  Are you your connectome?? -(video-connecto-spec.patterns in person brain-connections of brain, neurons;memories are not stored by genes(genetic code;DNA) but by connecto in brainconenctions) Intrapsychic Foundations ― being or occurring w/in the psyche,mind, or personality‖ Why study Freud? -we all‖speak‖ freud (make mistakes when you say something tht has a stronger resemblance,thinking sumthingyou blurt it out=Freudian slip -dream analysis;free association -unconcsious mind plays large role -ongoing research and theorising Driving Forces in Personality Eros(erotic, more positive one): the life instinct (preserve human life; (hunger, thrist, sexual needs;drving force=the libido) Thanatos: the death instinct (aggressive thoughts in action,returning of organic personality where they wud hv peace) *Human existence: constant struggle btw life and death instinct, btw individ’s desires and society (proposed w/in person: in individs society) Structure and Dynamics of the Psyche Tripartite model of the psyche: 1. Id: original and most primitive part 2. Ego: realistic aspect – satisfies demands of id and keeps it in check 3. Superego:internalization of society’s values consists of conscience and ego-ideal  A person consists of a balnce of these 3 Does the Structural Model hold up to empirical support? No evidence about proposed division of parts Ideas of conflict and behavioral compromise among forces that remain important -divisiaons of the mind:topographic model in text also incl: conscious(aware),preconscious (can be called into awareness…a cue),unconscious (unaccessible according to freud Relationship of structural and topographixc model -id is completely unconscious -when aware of wht Id wantsarises in anxiety -ego partly un/pre and conscious -superego(not directly interacts with Id) partly conscious and preconscious *which part of the structural model overlap? Defense Mechanisms (ego defending itself) Anxiety caused by id-superego conflict Unconscious aspect of ego attempts to defend ego from this conflict (conflicts btw id and superego (the unconscious aspect of ego produce anxiety) (id about sex) Repression:impulse prevented from reaching the conscious eg abuse Suppression:pushing impulse down consciously actively suppress eg.supressing sumthing Sublimation:transforming id impulses to more acceptable ones (every from id taken to transform to sumthing completely diff) Projection (ascribing undesirable impulses to others eg.knowing other person is selfish and then you say othr person does it) Rationalization:giving a ―rational explanation‖ eg. Done sumthing you shoudn’t hv done) Intellectualization:uncoupling thought and feeling eg.when feeling de-pride, you frame it in more intellectual terms Undoing:attempts to nullify an action/thought eg.forgot sumthing bad tht u did… Reaction formation:converting an unacceptable impulse into its opposite An Example of Reaction Formation: Homophobia ByAdams, Henry E.; Wright, Lester W.; Lohr, BethanyA.Journal ofAbnormal Psychology. Vol 105 (3),Aug 1996, 440-445. Agroup of homophobic men and a group of non-homophobic men were exposed to sexually explicit erotic stimuli consisting of heterosexual, male homosexual, and lesbian videotapes, and changes in penile circumference were monitored. Only the homophobic men showed an increase in penile erection to male homosexual stimuli. Theory of Psychosexual Development People pass through stages named thru body part tht is centre of sexual pleasure Conflict/trauma results in fixation on this conflict Stages of Psychosexual Development(don’t need to noe the ages for it) Oral (infant putting stuff in mouth) Oral receptive (overly indulging-sum1 who is actively spoon fed)character: dependent, too trusting, not competent Oral aggressive (opposite)character: envious, exploitative Anal (toilet training) Anal retentive (parents are strict,restrictspoopcharacter: obstinacy, orderliness, rigidity, frugality Anal expuanywhere)character: emotional outbursts, disorganization, generosity,p rebelliousness Stages of psychosexual development 2 Phallic *know culture reference, no need the story Phallic character in males: reaction to castration fear – reckless, bold behaviours (want to sexually possess their mothers, but then come afraid tht the father will castrate only way is to identify w/ father unconciously Phallic character in females: continual striving for superiority over men (cant relally solve/….dvelop penis envy) Latency stage (sexual dormant) Genital stage Genital character: mature and capable of adult intimacy *if pass all these stages will be able to approp. To develop an interdependence w/ an approp person) Problems with Freud’s Psychosexual Stages Latency Period Freud: no significant development in id impulses of erogenous zone Current thinking: important time of physical cognitive, social, and emotional development Freud: all stages must be successfully handled to navigate adulthood Current thinking: no clear support for predicted outcomes if all stage challenges not met Biased methods and sampling Inadequate developmental proof for Oedipal complex Gender differences in morality not supported Personality fixed and unchanging (suggesested tht at 5 but it is not true) Focus on sex and aggression How does Freud’s model of mid and memory compare to contemporary ideas Evidencecorrect:conscious and unconscious continuumcorrect:unconscious influence on consciousincorrect:unconscious not preoccupied w/ satisfying
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