PSYC 4520 1st EditionExam #3 Study Guide Lectures: 15-21Lecture 15 (October 10)Hans Eysenck’s Theory of PersonalityWho was Hans Eysenck?Eysenck was a psychologist who said that individual personality differences are due to physiological differences.Describe Eysenck’s structure of personality.Eysenck used factor analysis to identify the basic number of types (supertraits). He concluded that all traits can be subsumed within 3 basic personality dimensions: extraversion-introversion, neuroticism, and psychoticism.Describe Eysenck’s method of research.Eysenck divided the elements of personality into hierarchical units. His basic structure is the specific response level (specific behaviors: e.g. a man spending time laughing with friends). If this man spends many afternoons with these friends, this is a habitual response (the 2nd level in Eysenck’s model). If this man also spends time with other people/situations, we can say that he exhibits the trait of sociability (a specific trait, Eysenck’s 3rd level). Eysenck lastly said that traits like sociability are part of a larger dimension of personality; people who are sociable are also impulsive and lively. All these traits together form the supertrait called extraversion. Describe extraversion.An extravert is outgoing, impulsive, and uninhibited; he or she is sociable and likes having people to talk to. An introvert is quiet, introspective, reserved, and distant except to intimate friends. Most fall between these two extremes, but each of us is more one than the other.Describe neuroticism.Neurotics respond emotionally. They are unstable/highly emotional and have strong reactions to minor frustrations (they also take longer to recover). They are more easily upset/depressed. Those low in neuroticism do not fly off the handle or have large swings in emotion.Describe psychoticism.People high in this dimension are “egocentric, aggressive, impersonal, cold, impulsive, and unconcerned about others.” They are good candidates for judicial correction/psychotherapy.What did Eysenck say about the cerebral cortex arousal levels of introverts vs. extroverts?He said extroverts have a lower level of cortical arousal than introverts; extroverts seek outarousing social behavior because their cortical arousal is below their desired level (they try to avoid boredom). Introverts have a cortical arousal level that is near/above the optimal amount, so they want quiet environments to keep their already high arousal level from becoming higher.Does research support Eysenck’s cortical arousal level theory?No; introverts and extroverts show no differences in brain-wave activity when resting, but they do differ in how their brains respond to stimuli. Introverts are more sensitive to stimulation: they are more aroused by external stimulation and more responsive to chemical stimulants. So, due to physiological differences, introverts are more quickly overwhelmed by stimulation.Describe reinforcement sensitivity theory.It says that each human brain has a behavioral approach system (BAS) and a behavioral inhibition system (BIS). People with an active BAS seek/achieve goals; they get more pleasure from rewards and anticipating future rewards. They also are more upset when they do not reach these sources of pleasure. People with an active BIS are apprehensive; they approach newsituations warily, look out for danger, and retreat from problematic situations. They are more likely to have anxiety. Researchers connect the BAS and extraversion/BIS and neuroticism.What 3 arguments did Eysenck use to show that personality is shaped by biology?1. Consistency of extraversion-introversion over time: people who are more extroverted/ introverted generally remain so2. Cross-cultural research: we find the same 3 dimensions of personality in different countries. This consistency would not exist if biology did not determine personality.3. Results of studies indicating that genetics plays a role in shaping personality: research shows that your level of introversion/extraversion is strongly determined by your genetic makeup.Overall, he said that 2/3 of the variance in personality development can be traced to biology. This is a bit high, but data suggests that introverts/extroverts differ on biological measures.Heritability of Personality TraitsWhat is the idea of nature vs. nurture?It asks whether personality is shaped by genetic makeup or by environment and is a long-lastingdebate. Most people accept that both are important in shaping personality, so then we can ask how and to what extent are our personalities shaped by each aspect. Basically, researchers say that stable abilities/attitudes (e.g. intelligence) have a genetic component. We are born with a potential for intelligence that joins with environmental influences to determine intelligence levels as adults. Psychological disorders are also affected by genes (some people have a higher susceptibility). Genetics also influences personality traits like aggression and extraversion.Why is it difficult for psychologists to separate genetic influences from environmental?They cannot ethically manipulate people’s genes and observe the kinds of adults they become,so they use less direct means. The most obvious source of information on the “nature vs. nurture” debate is the similarity of parents and children. Aggressive parents often have aggressive kids, and shy parents shy kids. Many siblings are both outgoing or both sensitive. We often assume these traits were inherited, but family members share both genes AND living environments. Siblings may be similar because the parents raised them the same way.Describe the twin-study method.Because shared genes/environments overlap, they must be separated to study nature vs. nurture. The twin-study method does this by using the 2 types of human twins. Some are monozygotic (MZ—come from the same fertilized egg). Dizygotic (DZ) twins come from differenteggs. Dizygotic twins are fraternal—genetically distinct. With this method, we assume that 2 same-sex DZ twins and 2 MZ twins (always the same sex) share similar environments. Twin pairsare always the same age/sex and live in the same house with the same rules. So, the environment affects their personalities equally. But if there is a genetic influence, MZ twins should be more alike than the DZ twins, as the former also have identical genes. Researchers give personality trait measures to both members of both kinds of twins.