Psychology 3051 Psychology 305: Theories of Personality Lecture 7

Psychology 3052 Exam Tips The exam will contain questions reflecting both lecture content and textbook content. You are encouraged to study both sources of information thoroughly. When studying the material presented in the textbook, it may be helpful to create questions with the title and subtitles of each section. Use the content of each section to answer the questions that you have generated. It may also be helpful to identify the primary points of each section with key words or phrases and use these key words or phrases to test yourself.

Psychology 3053 The multiple choice and short answer questions will assess your ability to recall course content, synthesize course content, and apply course content. Examples:

Psychology 3054 Recall: According to Eysenck’s theory of personality, ___________ is among the three primary dimensions of personality. (a) conscientiousness (b) openness to experience (c) extraversion (d) agreeableness (e) c and d

Psychology 3055 Synthesize: List three similarities and three distinctions between Eysenck’s theory of personality and the Five Factor Model of personality. (6 points) Apply: What is intrasexual selection? Generate an example of a human characteristic that is likely to have evolved through this process. (4 points)

Psychology 3056 Apply: Personality assessments indicate that Jennifer is high in aggressiveness. However, Jennifer does not consistently act in an aggressive manner—she aggresses only in situations in which she feels threatened. Which of the following theoretical perspectives best explains the variation in Jennifer’s aggressive behaviour across situations? (a) The dispositional perspective. (b) The interactionist perspective. (c) The situationist perspective. (d) The trait perspective.

Psychology 3057 In order to correctly respond to questions that require synthesis and application, recall of information is necessary. The correlation between recall questions and synthesis/application questions typically exceeds.70.

Psychology 3058 Lecture 7 Questions That Will be Answered in Today’s Lecture Biological Perspective on Personality: Behavioural Genetics Approach, continued 1. What are the goals of behavioural genetics? (continued) 2. What are heritability and environmentality and how are they assessed? 3. What personality characteristics are heritable?

Psychology 3059 Physiological Approach 1.Case example: Who was Phineas Gage? 2.What physiological theories of personality were proposed by early scientists? 3. What physiological measures are commonly used in contemporary personality research? 4. What does contemporary research suggest about the physiological basis of (a) extraversion and (b) sensitivity to reward and punishment?

Psychology Goal 2: To identify the genetic factors that contribute to individual differences in specific personality characteristics. E.g., the gene D4DR on chromosome 11 contributes to individual differences in “sensation seeking.” Goal 3: To identify the environmental factors that contribute to individual differences in specific personality characteristics. What are the goals of behavioural genetics? (continued)

Psychology Heritability: The proportion of phenotypic variance that is attributable to genotypic variance. What are heritability and environmentality and how are they assessed? Phenotypic variance: Individual differences in an observable characteristic (e.g., height, weight, aggression, ambition, extraversion). Genotypic variance: Individual differences in genetic makeup.

Psychology E.g., Heritability of aggression =.67. Indicates that 67% of the observed variance in aggression within a population is due to individual differences in genetic makeup.

Psychology Environmentality: The proportion of phenotypic variance that is attributable to variance in environmental factors. E.g., Environmentality of ambition =.62. Indicates that 62% of the observed variance in ambition within a population is due to individual differences in environmental factors.

Psychology Heritability and environmentality are assessed using 3 methods: 1. Family Studies  Examine whether or not participants are more similar to immediate family members than distant family members with respect to a given personality characteristic.

Psychology Proportion of genes shared Parents and children Non-twin siblings Grandparents and grandchildren Aunts/uncles and nieces/nephews First cousins 50% 25% 12.5%

Psychology  For a given personality characteristic, two correlations are calculated: r 2 : The correlation between participants’ scores and the scores of their distant family members on the characteristic (reflects a relatively small degree of genetic overlap). r 1 : The correlation between participants’ scores and the scores of their immediate family members on the characteristic (reflects a relatively large degree of genetic overlap).  r 1 > r 2 indicates that the personality characteristic is heritable.

Psychology Adoption Studies  Examine whether or not adopted children are more similar to their biological parents than their adoptive parents with respect to a given personality characteristic.  A more powerful means by which to assess heritability and environmentality.

Psychology  For a given personality characteristic, two correlations are calculated: r 2 : The correlation between participants’ scores and the scores of their adoptive parents on the characteristic (reflects the influence of shared environment).  r 1 > r 2 indicates that the personality characteristic is heritable. r 1 : The correlation between participants’ scores and the scores of their biological parents on the characteristic (reflects the influence of shared genes).

Psychology Twin Studies  Examine whether or not monozygotic (MZ) twins are more similar than dizygotic (DZ) twins with respect to a given personality characteristic.  The most powerful means by which to assess heritability and environmentality.  MZ twins share 100% of the same genes; DZ twins share 50% of the same genes.

Psychology  For a given personality characteristic, two correlations are calculated: r 2 : The correlation between DZ twin pairs on the characteristic (reflects a relatively small degree of genetic overlap).  r 1 > r 2 indicates that the personality characteristic is heritable. r 1 : The correlation between MZ twin pairs on the characteristic (reflects a relatively large degree of genetic overlap).

Psychology  E.g., Computation of the heritability and environmentality of dominance using data obtained from a twin study: r 1 =.57 (MZ twins) r 2 =.12 (DZ twins) Heritability = 2 (r 1 – r 2 ) Environmentality = (1.00 – heritability) These results indicate that 90% of observed variance in dominance is due to individual differences in genetic makeup, whereas 10% of observed variance in dominance is due to individual differences in environmental factors. = 2 (.57 –.12) =.90 = =.10

Psychology What personality characteristics are heritable? Temperaments Buss and Plomin (1984) define temperaments as personality characteristics that appear during the 1 st year of life, persist across the lifespan, have a pervasive influence on behaviour, and are highly heritable. These researchers have identified 3 distinct temperaments.

Psychology Activity level: Refers to the degree to which an individual expends physical energy through motor activity (reflected in intensity of behaviour and speed of action). 2.Sociability: Refers to the degree to which an individual prefers to be with others rather than be alone. 3.Emotionality: Refers to the degree to which an individual becomes physiologically aroused in upsetting situations. Buss and Plomin maintain that there are 3 components of emotionality: anger, distress, and fear.

Psychology EAS Temperament Survey Score on items: 2, 7, 10, 17 = Activity Level 1, 6, 15, 20 = Sociability 5, 8, 13, 18 = Emotionality: Anger 4, 9, 11, 16 = Emotionality: Distress 3, 12, 14, 19= Emotionality: Fear

Psychology EAS Temperament Survey Means and Standard Deviations (Naerde et al., 2004), N = 939 MeanSD Activity level Sociability Emotionality: Anger Emotionality: Distress Emotionality: Fear

Psychology Heritability statistics (Wlodzimierz et al.,2003): Activity level:.58 Sociability:.42 Emotionality—Anger:.62 Emotionality—Distress:.54 Emotionality—Fear:.70

Psychology The Big 5 Dimensions Research suggests that the dimensions of the Big 5 are heritable. Heritability statistics (Jang et al., 1998): Extraversion:.50 Agreeableness:.48 Conscientiousness:.49 Neuroticism:.49 Openness to Experience:.48

Psychology Personality Characteristics Related to Psychopathy Heritability statistics (Blonigen et al., 2003; Bouchard et al., 1990; Tellegen et al., 1988): Fearlessness …………………………………………… >.95 Carefree Nonplanfulness (i.e., impulsiveness)…… Machiavellianism (i.e., enjoys manipulating others) Social potency (i.e., skilled at influencing others) …..66 Aggressiveness ………………………………………...67 Research suggests that characteristics related to psychopathy are heritable.

Psychology Heritability statistics (Bouchard et al., 1990; Tellegen et al., 1988) Creativity or imagination …………………………..74 Sense of alienation ………………………… Traditionalism ……………………………………….59 Low risk taking ……………………………… Achievement orientation ………………… Other Personality Characteristics Research suggests that there are a number of other characteristics that are heritable.

Psychology Scoring Your Questionnaire 1.Reverse score items 10 and Sum the following items: 1, 4, 7, 10, 12, 15, 19 2, 3, 5, 6, 8 9, 11, 13, 18 14, 16, 17, 20

Psychology Case Example: Who was Phineas Gage? Phineas Gage was a 19 th century rail worker involved in construction in Vermont. In 1848, an accidental explosion blew an iron rod through his head. The rod was approximately 1.25 inches in diameter and 3 feet long. The rod entered under his left cheek and passed through his frontal lobes, ultimately exiting through the top of his head. Physiological Approach

32 The Skull of Phineas Gage,

33 Reconstruction of the Path of the Iron Rod Through Gage’s Skull

Psychology According to Gage's physician, Gage’s personality radically changed after the accident. His physician reported that: Gage was fitful, irreverent, indulging at times in the grossest profanity (which was not previously his custom), manifesting but little deference for his fellows, impatient of restraint or advice when it conflicts with his desires, at times obstinate, yet capricious and vacillating, devising many plans of future operations, which are no sooner arranged than they are abandoned in turn for others appearing more feasible. A child in his intellectual capacity and manifestations, he has the animal passions of a strong man. Previous to his injury, although untrained in the schools, he possessed a well-balanced mind, and was looked upon by those who knew him as a shrewd, smart businessman, very energetic and persistent in executing all his plans of operation. In this regard his mind was radically changed, so decidedly that his friends and acquaintances said he was “no longer Gage.” (Harlow, 1948)

Psychology Neurologist Antonio Damasio has written extensively on Gage. According to Damasio, Gage's story marks the historical beginnings of the scientific study of the physiological basis of personality.

Psychology Physiological Approach: What physiological theories of personality were proposed by early theorists? What physiological theories of personality were proposed by early scientists? One of the earliest recorded physiological theories of personality was proposed by Roman physician Galen in A.D Building on the work of Greek physician Hippocrates, Galen proposed the Bodily-Fluid Theory of Personality. This theory maintains that the amount of four fluids present in the body determine personality.

Psychology  Excessive phlegm:  Excessive blood:  Excessive yellow bile:  Excessive black bile: Passive, calm, and thoughtful (i.e., phlegmatic) personality. Happy, outgoing, and optimistic (i.e., sanguine) personality. Unstable, aggressive, and irritable (i.e., choleric) personality. Unhappy, pessimistic, and somber (i.e., melancholic) personality.

Psychology Galen’s theory remained in favor for centuries. However, the theory fell out of favor with advances in physiology. An early, modern physiological theory of personality that was influential for some time was proposed by William Sheldon. His Somatotype Theory of Personality suggests that body type determines personality. Sheldon’s theory distinguishes between 3 body types:

Psychology 30539

Psychology Sheldon assigned individuals “somatotype ratings.” These ratings are comprised of 3 numbers, each ranging from 1 to 7. The numbers reflect an individual’s scores on the 3 dimensions of obese, muscular, and thin, respectively.

Psychology According to Somatotype Theory, the following characteristics are associated with each body type:  Ectomorph (“skinny”): Apprehensive, introverted, and restrained personality (cerebrotonia temperament).  Mesomorph (muscular): Assertive, adventurous, and bold personality (somatotonia temperament).  Endomorph (“fatty”): Sociable, relaxed, and fun- loving personality (viscerotonia termperament).

Psychology In contrast to Sheldon, most contemporary personality psychologists do not focus on global variables such as gross body type. Sheldon reported research findings to support his theory. However, efforts to replicate these findings were unsuccessful.

Psychology Today, the vast majority of researchers in this area employ measures of distinct physiological systems (e.g., heart rate). The primary goal of contemporary research is to identify differences in the physiological responses of individuals with distinct personality characteristics.

Psychology What physiological measures are commonly used in contemporary personality research? Four physiological measures are of particular interest to contemporary personality psychologists: 1. Measures of Electrodermal Activity (Skin Conductance)  Assess the concentration of water or sweat on the palms.  Provide a direct measure sympathetic nervous system activity (i.e., the fight-or-flight response).

Psychology  Typically, this technique involves placing 2 electrodes on the palm of one hand. A very low voltage of electricity is sent through one electrode into the skin. The amount of electricity detected at the second electrode assesses how well the skin is conducting electricity.  E.g., Research assessing electrodermal activity suggests that people who are high in neuroticism have chronically activated sympathetic nervous systems.

Psychology Measures of Cardiovascular Activity  Include measures of blood pressure and heart rate.  Blood pressure and heart rate provide direct measures of sympathetic nervous system activity.  E.g., Research assessing cardiovascular activity suggests that people who are characterized by impatience, competitiveness, and hostility (i.e., the “Type A” personality) experience chronic cardiac reactivity, a condition that contributes to heart disease.

Psychology Measures of Brain Activity  Include positron emission tomography (PET) and functional magnetic resonance imaging (fMRI).  PET involves administering a radioactive substance to the participant. The radioactive substance is typically attached to glucose. The PET scanner detects the emission of positrons from the radioactive substance, thereby indicating where glucose consumption and physiological activity is greatest.

48 PET Image of the Brain

Psychology  fMRI uses radio waves and strong magnetic fields to produce an image of physiological activity. fMRI identifies regions in the brain where blood vessels are expanded and extra oxygen is being delivered, thereby indicating where physiological activity is greatest.

50 fMRI Image of the Brain

Psychology  E.g., Research employing fMRI suggests that individuals who are high in neuroticism experience increased frontal brain activation when exposed to negative images, whereas individuals who are high in extraversion experience increased frontal brain activation when exposed to positive images.

Psychology Biochemical Measures of Blood and Saliva  Assess hormone levels (e.g., testosterone) and enzyme levels (e.g., monoamine oxidase).  E.g., Research suggests that shy children have relatively high levels of cortisol in their systems. Cortisol is a byproduct of noradrenaline, a hormone released under stress.

Psychology What does contemporary research suggest about the physiological basis of extraversion? Eysenck (1967) proposed a physiological theory to account for individual differences in extraversion. According to Eysenck’s theory, the ascending reticular activating system (ARAS) plays a critical role in determining levels of extraversion. The ARAS is a structure in the brainstem that controls cortical arousal. High levels of ARAS activity result in high levels of cortical arousal. Low levels of ARAS activity result in low levels of cortical arousal.

Psychology Eysenck suggested that introverts have relatively high levels of ARAS activity and, therefore, relatively high levels of cortical arousal. In order to avoid further arousal, introverts restrain themselves, seek low-stimulation settings, and avoid social interactions that may exacerbate their often over stimulated condition. That is, introverts engage in activities that regulate their levels of arousal downward.

Psychology In contrast, Eysenck suggested that extraverts have relatively low levels of ARAS activity and, therefore, relatively low levels of cortical arousal. In order to enhance their levels of arousal, extraverts seek high-stimulation experiences, settings, and social interactions. That is, extraverts engage in activities that regulate their levels of arousal upward.

Psychology Research has provided support for Eysenck’s theory.  E.g., Brebner & Cooper (1978) Found that extraverts pushed a button at a higher rate than introverts when pushing the button resulted in a change in the visual environment.  E.g., Campbell & Hawley (1982) Found that extraverts were more likely to study in noisy reading rooms, whereas introverts were more likely to study in quiet reading rooms.

Psychology  E.g., Geen (1984) Found the following: (b) When extraverts were asked to complete the learning task under the noise level preferred by introverts, they became bored (i.e., under aroused) and their performance deteriorated. (a) Extraverts preferred to undertake a learning task under noisier conditions than introverts. (c) When introverts were asked to complete the learning task under the noise level preferred by extraverts, they became distressed (i.e., over aroused) and their performance deteriorated.

Psychology What does contemporary research suggest about the physiological basis of sensitivity to reward and punishment? Gray (1972, 1990) proposed a physiological theory to account for individual differences in sensitivity to reward and punishment: Reinforcement Sensitivity Theory. Gray’s theory hypothesizes that there are two systems within the brain that respond to reward and punishment: The behavioural activation system (BAS) and the behavioural inhibition system (BIS). The BAS is based in the left prefrontal cortex. The BIS is based in the right prefrontal cortex.

Psychology Gray maintained that the BAS is responsive to rewards or incentives, generates positive emotions (e.g., eagerness, excitement), and regulates “approach” behaviours. E.g., In a child, the BAS would recognize music emanating from an ice cream truck as a reward cue, would generate positive emotions in response to that cue, and would create an urge to run to the truck.

Psychology The BAS appears to be linked to dopamine levels. Gray believed that the BAS is responsible for the personality dimension of extraversion or impulsivity.

Psychology In contrast, Gray maintained that the BIS is responsive to punishment or frustration, generates negative emotions (e.g., anxiety, fear), and regulates “avoidance” behaviours. E.g., In a child who is shouting, the BIS would recognize a mother’s stern glance as a punishment cue, would generate negative emotions in response to that cue, and would inhibit further shouting.

Psychology The BIS appears to be linked to serotonin levels. Gray believed that the BIS is responsible for the personality dimension of neuroticism or anxiety.

Psychology Questions That Were Answered in Today’s Lecture Biological Perspective on Personality: Behavioural Genetics Approach, continued 1. What are the goals of behavioural genetics? (continued) 2. What are heritability and environmentality and how are they assessed? 3. What personality characteristics are heritable?

Psychology Physiological Approach 1.Case example: Who was Phineas Gage? 2.What physiological theories of personality were proposed by early scientists? 3. What physiological measures are commonly used in contemporary personality research? 4. What does contemporary research suggest about the physiological basis of (a) extraversion and (b) sensitivity to reward and punishment?