Behavior Genetic Studies of Normal and Abnormal Personality

Behavior Genetic Studies of Normal and Abnormal Personality

Theories of Personality

• Personality psychology became an identifiable

discipline in the social sciences in the 1930’s

• Primarily stimulated by Allport’s 1937 Personality: A psychological interpretation, which focused on traits

• Through the 1930’s and 1940’s several influential psychologists proposed alternative theories of personality:

Notably:

• Murray- introduced the notion of needs (needs for achievement, for dominance, for succorance, etc.)

• Lewin – saw behavior as a dynamic interaction between people and their environments

• Miller – believed all significant human behavior is learned in specific social, cultural, and historical contexts

• In the 1940’s and 1950’s, personality psychologists started to employ factor analysis, leading to several factor theories of personality:

• Cattell:

– defined personality as “that which permits a prediction of what a person will do in a given situation.”

– developed a scale tapping 16 factors (traits) of personality

• Eysenck:

– proposed 3 broad personality traits:

– extraversion/introversion, neuroticism, psychoticism

(The Giant 3)

– he also believed that individual differences in personality are determined by underlying neurophysiological mechanisms and, thus, are substantially heritable

• In the 1950’s to 1970’s, experimental social psychology and the growing discipline of clinical psychology overshadowed personality psychology, which witnessed a gradual erosion of its identity during this period

• This resulted in personality psychologists moving away from the development of grand theories to a more data-driven, empirical approach

• This, in turn, led to an interest in measurement issues and test construction

• Numerous empirically-validated personality questionnaires were developed during this period (e.g. Jackson’s Personality Research Form, the California Psychological Inventory, the MMPI among others)

• Critics charged that ‘personality,’ as measured by such tests, bore little resemblance to ‘real’ human behavior

• Countercriticisms led to an improvement in the personality tests’ predictive power

• In the 1980’s and 1990’s, personality psychology enjoyed a renewed popularity and many behavior genetic studies were conducted

• Related topics of research included health psychology, life-span development, personal relationships, shyness, and the biological basis of personality

• Currently, the most popular and influential model of personality is Costa and McCrae’s “Big Five” Trait Taxonomy

The Big Five (OCEAN)

• Openness

• Conscientiousness

• Extraversion

• Agreeableness

• Neuroticism

• measured by the NEO personality Inventory and its revised versions

• Each dimension measured by the NEO-PI-R has 6 facets, for example:

– Neuroticism: anxiety, hostility, depression

– Extraversion: warmth, assertiveness

– Openness: ideas, fantasy

– Agreeableness: trust, modesty, straightforward

– Conscientiousness: duty, self-discipline

BG Studies of Personality

Key findings:

• Nearly all personality traits show at least moderate heritability

• There is no replicated report of zero heritability for any specific personality trait

• Virtually all environmental influences are non-shared

• One implication of this is that parenting may not play as critical a role in personality development as many have assumed

• The most frequently studied traits are extraversion and neuroticism

Twin, Family, and Adoption Results for Extraversion and Neuroticism

Kinship Extraversion Neuroticism

MZT .51 .46MZA .38 .38DZT .18 .20DZA .05 .23Parent/Child .16 .13Adoptive Parent/Child .01 .05Birth sibs .20 .09Adoptive sibs -.07 .11

Conclusions

• Extraversion is moderately heritable

• rMZA = .38 = h2

• 2(rMZT – rDZT) = 2(.51 - .18) = .66 = h2

• Neuroticism results are more variable

• rMZA = .38• 2(rMZT – rDZT) = 2(.46 - .20) = .52

• But, birth sib correlation = .09

Jang et al. (1996)

• Administered the NEO-PI-R to 123 MZ and 127 DZ pairs; model-fitting results:

Trait rMZ rDZ a2 d2 c2 e2

Neuroticism .41 .18 .41 .59

Extraversion .55 .23 .53 .47

Openness .58 .21 .61 .39

Agreeableness .41 .26 .41 .59

Conscientiousness .37 .27 .44 .56

Jang et al. (1996)

Model-fitting results for NEO-PI-R facets1. Neuroticism

Facet rMZ rDZ a2 d2 c2 e2 Anxiety .26 .13 .26 .74

Angry hostility .37 -.01 .33 .67

Depression .33 .14 .31 .69

Self-conscious .38 .19 .38 .62

Impulsive .36 .21 .36 .64

Vulnerability .45 .17 .44 .56

2. Extraversion

Facet rMZ rDZ a2 d2 c2 e2

Warmth .43 .14 .43 .57

Gregariousness .56 .19 .52 .48

Assertiveness .42 .10 .42 .58

Activity .29 .14 .29 .71

Excitement-seeking .42 .02 .41 .59

Positive emotions .38 .24 .39 .61

3. Openness

Facet rMZ rDZ a2 d2 c2 e2

Fantasy .32 .22 .34 .66

Aesthetics .60 .14 .57 .43

Feelings .44 .35 .39 .61

Actions .42 .21 .44 .56

Ideas .53 .09 .52 .48

Values .49 .27 .51 .49

4. Agreeableness

Facet rMZ rDZ a2 d2 c2 e2

Trust .27 .21 .30 .70

Straight-forwardness .47 .17 .47 .53

Altruism .34 .18 .34 .66

Compliance .33 .10 .34 .66

Modesty .30 .36 .33 .67

Tender-mindedness .41 .15 .45 .55

5. Conscientiousness

Facet rMZ rDZ a2 d2 c2 e2

Competence .37 .13 .34 .66

Order .25 .23 .44 .56

Dutifulness .42 .23 .44 .56

Achievement-striving .41 .18 .42 .58

Self-discipline .30 .37 .34 .66

Deliberation .26 .18 .23 .77

Meta-Analysis of 50+ Years of BG Research (Johnson, Vernon, Feiler, 2008)

• 127 Personality Variables in Total• 83 Different Tests/Questionnaires

145 Studies from 1955-2007

85,640 MZ Pairs106,644 DZ Pairs46,215 Other Kinship Pairs

Within Studies Sample Sizes

21-5568 Pairs MZ Twins10-7873 Pairs DZ Twins20-7823 Pairs Other Kinships

4 Months – 96 Years

Kinship Correlations, Heritabilities, and Model-fitting Results for Openness to Experience

0.10 to 0.57 0.43

60 8961 -0.27 to 0.42

0.36

23 367 -0.02 to 0.34

0.14

6 1363 0.05 to 0.32 0.26

1 3241 0.13 0.13

6 237 0.08 to 0.42 0.23

2 203 0.23 to 0.27 0.25

3 120 0.06 to 0.37 0.24

6 1097 0.00 to 0.24 0.12

0.20 to 0.78 0.46

37 18104 0.04 to 0.81 0.43

10 3119 0.00 to 0.30 0.11

4 6046 0.02 to 0.39 0.10

40 19214 0.19 to 0.81 0.49

Kinship

(1.0)MZT

DZT (.05)

(1.0)

DZA

MZA

DZO

(.05)

(0.5)

Biological Siblings (0.5)

Biological Parent / Child (0.5)

Spouses (0.0)

Adopted Siblings (0.0)

Adoptees / Adopted Parents (0.0)

h2

a2

c2

d2

e2

62 12549 0.18 to 0.69 0.49

8 368

25 12091

No. ofReportedValues

No. of Pairs Range Median

Kinship Correlations, Heritabilities, and Model-fitting Results for Conscientiousness

Kinship No. ofReported Values

No. of Pairs

Range Median

MZT (1.0) 113 18702 0.14 to 0.85 0.47

MZA (1.0) 16 552 0.01 to 0.64 0.36

DZT (0.5) 110 13346 -0.27 to 0.53 0.21

DZA (0.5) 16 665 -0.28 to 0.40 0.09

DZO (0.5) 10 1117 -0.03 to 0.57 0.26

Biological Siblings (0.5) 8 4348

-0.04 to 0.29 0.15

Biological Parent / Child (0.5) 6 237 -0.07 to 0.07 -0.02

Biological Half-Siblings (0.25) 2 109 0.01 to 0.02 0.02

Spouses (0.0) 3 203 -0.15 to 0.31 0.00

Adopted Siblings (0.0) 6 270 -0.14 to 0.12 0.02

Adoptees / Adopted Parents (0.0) 6 1097 0.01 to 0.13 0.04

h2 49 20630 0.00 to 0.76 0.46

a2 71 21105 0.00 to 0.78 0.41

c2 25 5947 0.01 to 0.61 0.27

d2 15 7817 0.07 to 0.50 0.29

e2 82 27401 0.15 to 1.00 0.59

Kinship Correlations, Heritabilities, and Model-fitting Results for Extraversion

Kinship No. of Reported Values

No. of Pairs Range Median

MZT (1.0) 195 32184 0.08 to 0.89 0.49

MZA (1.0) 22 366 -0.15 to 0.53 0.21

DZT (0.5) 192 32691 -0.28 to 0.63 0.20

DZA (0.5) 24 569 -0.01 to 0.40 0.12

DZO (0.5) 19 4357 0.07 to 0.59 0.29

Biological Siblings (0.5) 13 4189 0.05 to 0.20 0.11

Biological Parent / Child (0.5) 27 970 -0.02 to 0.62 0.30

Biological Half-Siblings (0.25) 4 344 0.03 to 0.04 0.04

Spouses (0.0) 3 203 0.05 to 0.22 0.14

Adopted Siblings (0.0) 15 735 -0.45 to 0.59 -0.05

Adoptees / Adopted Parents (0.0) 24 1503 -0.09 to 0.20 0.05

h2 89 45481 0.00 to 0.88 0.49

a2 109 37602 0.00 to 0.70 0.48

c2 44 14452 0.01 to 0.49 0.15

d2 10 6452 0.00 to 0.64 0.06

e2 109 37602 0.07 to 0.96 0.48

Kinship Correlations, Heritabilities, and Model-fitting Results for Agreeableness

Kinship No. of Reported Values

No. of Pairs Range Median

MZT (1.0) 148 22331 0.07 to 0.88 0.46

MZA (1.0) 13 446 0.16 to 0.55 0.33

DZT (0.5) 149 17031 -0.14 to 0.58

0.23

DZA (0.5) 10 699 0.03 to 0.43 0.11

DZO (0.5) 21 7661 0.09 to 0.58 0.45

Biological Siblings (0.5) 3 596 0.01 to 0.12 0.10

Biological Half-Siblings (0.25) 1 109 0.03 0.03

Spouses (0.0) 1 111 0.25 0.25

Adopted Siblings (0.0) 2 150 0.14 0.14

h2 37 8189 0.00 to 0.94 0.40

a2 71 29953 0.06 to 0.78 0.47

c2 41 22146 0.01 to 0.43 0.15

d2 5 3032 0.22 to 0.34 0.27

e2 75 31432 0.11 to 0.84 0.48

Kinship Correlations, Heritabilities, and Model-fitting Results for Neuroticism Kinship No. of Reported

ValuesNo. of Pairs

Range Median

MZT (1.0) 341 75974 0.03 to 0.90 0.47

MZA (1.0) 41 590 -0.06 to 0.62 0.34

DZT (0.5) 348 68725 -0.18 to 0.78 0.22

DZA (0.5) 42 1005 -0.26 to 0.46 0.11

DZO (0.5) 61 27008 -0.07 to 0.58 0.32

Biological Siblings (0.5) 24 14485 -0.05 to 0.37 0.12

Biological Parent / Child (0.5) 20 8677 0.00 to 0.35 0.11

MZ Twin / Co-twin’s Child (0.5) 6 284 -0.05 to 0.23 0.19

Adoptees / Biological Parent (0.5) 9 606 -0.04 to 0.31 0.04

Biological Half-Siblings (0.25) 7 579 -0.05 to 0.31 0.16

Spouses (0.0) 8 7273 -0.01 to 0.23 0.07

MZ Twin / Co-twin’s Spouse (0.0) 2 221 0.08 to 0.13 0.10

Adopted Siblings (0.0) 12 997 -0.20 to 0.29 0.07

Adoptees / Adopted Parents (0.0) 8 760 -0.01 to 0.19 0.07

MZ Twin’s Spouse/Co-twin’s Child (0.0) 4 206 0.03 to 0.11 0.07

h2 152 98125 0.00 to 0.90 0.45

a2 215 102924 0.04 to 0.82 0.44

c2 91 51050 0.01 to 0.71 0.13

d2 29 9079 0.02 to 0.61 0.26

e2 229 104058 0.06 to 0.96 0.51

Summary of Key Findings

• Individual differences in the Big 5 are largely attributable to additive genetic and non-shared environmental factors

• The contributions of dominance genetic and shared environmental factors are small to negligible

• Across studies, twin and kinship correlations and model-fitting results are very consistent

• Some evidence that Extraversion is the most highly heritable and that Agreeableness is the least heritable but overall the variables are fairly equally heritable (h2 = .45)

• Some evidence for assortative mating, especially for Openness and Agreeableness

• MZA correlations are smaller than MZT correlations (.33 vs. .48, on average)

• Compare this to the results of Bouchard’s studies of MZAs

Bouchard’s MZA (and DZA) Minnesota Study

• 74 pairs of MZAs, 54 pairs of DZAs

• Found all over the world

• On average, separated prior to 5 months of age and not re-united until 30 years old

• Twin week: 50 hours of physical, psychological, and medical tests

• The ‘Jim Twins’

Jim Twins Coincidences (?)

• Both married Lindas, divorced, then married Bettys

• Named their sons James Alan and James Allan

• Named their boyhood pet dogs Toy

• Worked as deputy-sheriffs; worked at McDonald’s, worked as attendants at gas stations

• Drove the same model car (a Chevrolet)

• Drink the same brand of beer (Miller’s Lite)

• Smoke the same brand of cigarettes (Salems)

• Enjoy car-racing and dislike baseball

• Enjoy doing household chores on weekends

• As teenagers, put on 10 pounds for no apparent reason, then lost it at the same time later

Key Results from the Bouchard StudyBouchard et al. (1990), Science, 250, 223-228

rMZA rMZT

Mean of 11 MPQ scales .50 .49Mean of 18 CPI scales .48 .49Mean of 23 Strong-Campbell .39 .48interest scalesMean of 34 Jackson vocational .43 N/Ainterest scalesOccupational interests .40 .49Religiosity .49 .51Non-religious social attitudes .34 .28 Traditionalism .53 .50

Behavior Genetic Studies of Aggression

Types of Aggression

• Physical

• Verbal

• Self-harm

• Hostility

• Anger

• Impatience

• Irritability

• Affective-instability

• Aggressive attitudes

• Impulsivity

• Nonconformity

• Resentment

• Suspiciousness

• Malice

• Negativism

• Rebelliousness

• Boldness

• Vengefulness

• Lack of self control

• Road rage

Choynowski (1995) Factor Structure of Aggression

General Aggression

Rebelliousness Spontaneous Intra- Irritable

(.583) Aggression Aggressiveness Aggressiveness

(.433) (.453) (.517)

Nonconformity Physical Self- Irritability

(.762) Aggression Aggression (.707)

(.860) (.633)

Verbal Boldness Resentment Lack of

Aggression (.632) (.768) Self-control

(.843) (.806)

Malice Vicarious Suspiciousness Vengefulness

(.806) Aggression (.624) (.728)

(.775)

Negativism

(.775) 940 Items/ 25 Scales

Previous Behavior Genetic Studies of Aggression (N = 13)

Measures Number of Studies Sample Sizes (MZ/DZ) Ages h2 Range (M)

Verbal 1 77/21 Adults .70

Physical 5 39-77/21-44 7 1/2 - Adults 0 -.60 (0)

Indirect 1 77/21 Adults .78

Anger 1 77/21 Adults .76

Irritability 2 77-108/21-135 Adults .48 - .98 (.73)

Hostility 1 77/21 Adults .3

Overall 7 21 - 504/17-328 4-Adults .18 - .94 (.59) 0 - .98 (.53)

Veselka & Vernon (2009)

• Updated meta-analysis of 42 years of BG studies of aggression

• 91 twin studies with > 90,000 pairs of twins in total

• Similar wide range of heritabilities

Vernon et al. (1999)

Sample

• 245 same-sex adult twin pairs

• 181 MZ (147 F, 34 M)

• 64 DZ (55 F, 9 M)

• Ages: X = 44.3, S = 16.6

• Recruited from U.B.C. twin registry and “Twins Day” Festival participants

1. Adjective Checklist (+ ACL-Revised)

– overall aggression

2. Personality Assessment Inventory

– verbal aggression

– affective instability

– self-harm

– anti-social behavior

– physical aggression

– aggressive attitudes

Measures

3. Aggression Questionnaire– physical aggression– verbal aggression– hostility– anger

4. Aggression Inventory– physical aggression– impulsivity– verbal aggression– impatience

Measures Cont’d.

Measures Cont’d.

5. Multidimensional Personality Questionnaire

– overall aggression

6. Personality Research Form

– overall aggression

Factor Analysis of Aggression Variables

Variables 1 1 2 3

ACL AGG .54 .62

ACLR AGG .67 .75

VERB AGG .54 .51

AFF INST .74 .81

PAI SELF-HARM .60 .61

ANTSOC BEHAV .65 .46

PHYS AGG .74 .43 .47

AGG ATT .70 .43

PHYS AGG .72 .77

AGQ VERB AGG .66 .41 .41

HOSTILITY .59 .74

ANGER .78 .76

PHYS AGG .78 .86

IMPULSE .49 .58

AGI VERB AGG .67 .65

IMPAT .61 .51

MDP AGG .75 .81

PRF AGG .72 .37

Twin Correlations and Genetic Analyses of Aggression Variables

Variables MZ DZ a2 d2 c2 e2

ACL AGG .43 .34 .45 .55 ACLR AGG .39 .35 .38 .62 VERB AGG .37 .25 .37 .63 AFF INST .50 .17 .07 .45 .48 PAI SELF-HARM .40 .37 .39 .61 ANTISOC BEH .62 .38 .66 .34 PHYS AGG .31 .20 .33 .67 AGG ATT .36 .06 .35 .65 PHYS AGG .52 .16 .21 .31 .48 AGQ VERB AGG .49 .48 .48 .52 HOSTILITY .38 .30 .42 .58 ANGER .38 .21 .40 .60 PHYS AGG .49 .30 .49 .51 IMPULSE .22 .21 .22 .78 AGI VERB AGG .52 .38 .50 .50 IMPAT .38 .22 .36 .64 MDP AGG .46 .42 .45 .55 PRF AGG .42 .20 .42 .58

Twin Correlations and Genetic Analyses of Aggression Factors and Composites

Variables MZ DZ a2 c2 e2

GEN AGG .62 .39 .62 .38

FAC 1 .62 .32 .63 .37

FAC 2 .56 .29 .57 .43

FAC 3 .48 .35 .48 .52

VERBAL .51 .37 .50 .50

PHYSICAL .53 .23 .53 .47

AGG ATT .52 .28 .53 .47

Phenotypic Correlations between Factors and Composites

Fac 1 Fac 2 Fac 3 Verbal Physical AGG ATT

Fac 1 1 .68 .54 .82 .94 .69

Fac 2 1 .47 .50 .71 .98

Fac 3 1 .72 .42 .52

Verbal 1 .68 .55

Physical 1 .68

AGG ATT 1

Genetic Correlations Among Factors and Composites

Fac 1 Fac 2 Fac 3 Verbal Physical AGG ATT

Fac 1 1 .74 .66

Fac 2 1 .60

Fac 3 1

Verbal 1 .77 .60

Physical 1 .78

AGG ATT 1

Relationships between Intelligence and Personality

Theories Relating Intelligence to Personality

• Allport (1961): both linked to central nervous system

• Cattell (1965): intelligence is itself a personality trait

• Eysenck (1971): persistence and error-checking contribute to measured intelligence

• Eysenck (1984): identified neuropsychological mechanisms underlying intelligence and personality

• Costa & McCrae (1988): big 5 dimension of openness to experience

Personality Correlates of Intelligence

• Eysenck (1993): Psychoticism and FSIQ (-)

• Gormly & Gormly (1986): Introversion and spatial (+)

• Holland et al. (1995): Openness and FSIQ (+)

• Plant & Minium (1967): Dogmatism and FSIQ (-)

• Rawlings & Skok (1993): Venturesomeness and FSIQ (+)

• Robinson (1982): Introversion and verbal (+)

• Samuel (1980): Assertiveness and FSIQ (+)

Harris et al. (1998, 1999)

• Subjects: 142 pairs of adult twins (92 MZ, 50 same-sex DZ)

• Tests: Multidimensional Aptitude Battery

Personality Research Form-E• 20 personality traits

• Aggression, dominance, endurance, impulsivity

Zygosity questionnaire

Univariate Genetic Analyses

a2 c2 e2

PRF-E (median) .45 .51

MAB FSIQ .49 .38 .13

MAB VIQ .28 .57 .15

MAB PIQ .77 .23

Phenotypic and Genetic Correlations between PRF Traits and FSIQ

Trait Description rP rG

ACHIEVEMENT AMBITIOUS, COMPETITIVE .21 .22

AUTONOMY INDEPENDENT, SELF-RELIANT .15 .10

DOMINANCE DOMINANT, PERSUASIVE .25 .38

ENDURANCE PERSISTENT, ENDURING .14 .19

HARMAVOID FEARFUL, AVOID RISKS -.25 -.31

ORDER NEAT, ORGANIZED -.14 -.33

SENTIENCE PERCEPTIVE, AESTHETIC .12 .15

SUCCORANCE DEPENDENT, SEEK SUPPORT -.14 -.12

UNDERSTANDING INQUIRING, CURIOUS .36 .43

MULTIPLE CORRELATIONS .46 .59

Searching for e2

Environmental Contribution to Individual Differences

Shared Factors Non-shared Factors

- Contribute to twin similarities - Contribute to twin differences

- Typically small effect - Typically large effect

- Easy to identify - Largely unidentified

Vernon et al. (1997)

Sample

• 93 MZ pairs (74 F, 19 M)

• 50 same-sex DZ pairs (41F, 9M)

• 66 same-sex non-twin siblings (51F, 15M)

• Ages: X = 23.7, S = 6.48

• Average age difference between NT sibs: 16.4 months

• Recruited from UWO and UBC twin registries

1. Personality Research Form:– Extraversion– Conscientiousness– Autonomy– Neuroticism– Openness

2. Sibling Inventory of Differential Experience:– Sibling interactions– Parental interactions– Peer interactions

Measures

Measures Cont’d.

3. Family Environment Scale:– Acceptance/rejection– Restrictiveness/permissiveness

4. Classroom Environment Scale:– Interpersonal relations– Goal-orientation and order

5. Environmental Response Inventory:– Preservation– Sensation-seeking– Urban

Twin Correlations and Genetic Analyses of Personality Factors

Factors MZ DZ a2 d2 c2 e2

Extraversion .52 .32 .52 .48

Conscientiousness .27 .21 .30 .70

Autonomy .27 .16 .28 .72

Neuroticism .36 .22 .37 .63

Openness .59 .19 .58 .42

Twin Correlations and Genetic Analyses of Environmental Variables

Variables MZ DZ a2 d2 c2 e2

SIDESIBS .40 .50 .43 .57PARENTS .49 .66 .53 .47PEERS .57 .27 .58 .42

FESACCEPT .50 .36 .44 .56RESTRICT .53 .48 .51 .49

CES RELATIONS .31 .24 .29 .71GOALS/ORDER .44 .18 .47 .53

ERI PRESERVE .60 .24 .65 .35SENSATION .65 .31 .67 .33URBAN .43 .14 .47 .53

1. MZ Twins:

– Autonomy: ERI Sensation-seeking (.39)

ERI Urban (.25)

SIDE Parents (.28)

3 ERI Factors (adjusted R2 = .17)

– Neuroticism: ERI Urban (.27)

Environmental Predictors Cont’d.

2. DZ Twins:

– Autonomy: ERI Sensation-seeking (.68)

ERI Urban (.63)

ERI Preservation (.47)

SIDE Parents (.26)

3 ERI Factors (adjusted R2 = .23)

– Conscientiousness: 3 ERI Factors (adjusted R2 = .44)

All 4 environmental sets (adjusted R2

= .51)

Environmental Predictors Cont’d.

Environmental Predictors Cont’d.

3. Non-twin sibs:

– Autonomy: SIDE Parents (.22) CES Relations (.41) 2 CES Factors (adjusted R2 = .15) All 4 environmental sets (adjusted R2 = .49)

– Conscientiousness: ERI Sensation-seeking (.42) SIDE Parents (.23) 3 ERI Factors (adjusted R2 = .14) All 4 environmental sets (adjusted R2 = .20)

Non-twin sibs:

– Neuroticism: FES Acceptance-rejection (.33)

2 FES Factors (adjusted R2 = .08)

– Openness: ERI Sensation-seeking (.40)

3 ERI Factors (adjusted R2 = .15)

All 4 environmental sets (adjusted R2 = .23)

Environmental Predictors Cont’d.

Environmental Predictors of Autonomy Differences

1. MZ twins: SIDE Parents (.28)

2. DZ twins: SIDE Parents (.26)

3. Non-twin sibs: SIDE Parents (.22) CES Relations (.41) All 4 sets (adjusted R2 = .49) - SIDE siblings (β = .35) - SIDE parents (β = .34) - FES accept/reject (β = .43) - CES relations (β = .61) - CES goals/order (β = .38)

• MZ twins only correlate about .50 on most measures of personality

• The differences between them are largely attributable to nonshared environmental factors

• Low heritability traits: autonomy (.28), conscientiousness

(.30), neuroticism (.37) had e2 correlates

• More heritable traits: extraversion (.52), openness (.58) had fewer e2 correlates

Ongoing BG Studies of Personality in the Western Ontario Twin Project

-Trait Emotional Intelligence

-The Dark Triad (Machiavellianism, narcissism, psychopathy)

-Moral Reasoning

-Sense of Humor

-Political Attitudes

-Material Values

-Mental Toughness

-General Factor of Personality

JPI-Organization (0.78)PRF-Impulsivity (-0.76)

PRF-Cognitive Structure (0.70)PRF-Order (0.67)

PRF-Achievement (0.64)PRF-Play (-0.64)

PRF-Endurance (0.53)

JPI-Interpersonal Affect (0.77)PRF-Succorance (0.69)PRF-Autonomy (-0.65)PRF-Nurturance (0.64)

JPI-Anxiety (0.60)JPI-Social Participation (0.58)PRF-Harm Avoidance (0.38)

PRF-Defendence (-0.81)PRF-Aggression (-0.74)PRF-Abasement (0.69)

JPI-Responsibility (0.51)PRF-Desirability (0.47)

JPI-Self Esteem (0.83)PRF-Exhibition (0.82)PRF-Dominance (0.64)PRF-Affiliation (0.62)

JPI-Energy Level (0.45)JPI-Social Adroitness (0.44)

JPI-Risk Taking (0.42)

JPI-Complexity (0.82)PRF-Understanding (0.79)

JPI-Breadth of Interest (0.74)JPI-Innovation (0.61)

JPI-Conformity (-0.60)JPI-Tolerance (0.55)

PRF-Social Recognition (-0.52)PRF-Sentience (0.50)PRF-Change (0.48)

JPI-Value Orthodoxy (-0.46)

ConscientiousnessEmotional Stability Agreeableness

Stability Plasticity

GFP

Extraversion Openness

.56.80

.63.51

.59.67 .59

The GFP and the Big Two from

36 PRF and JPI Traits

.53

.77 .72

.63.41

GFP

Extraverted (0.85)Fun Loving (0.81)

Sociable (0.76)Impulsive (0.68)

Attention Seeking (0.63)Changeable (0.57)

Aggressive (-0.75)Dominant (-0.68)

Authoritarian (-0.59)Independent (-0.55)Ambitious (-0.54)

Neurotic (-0.87)Anxious (-0.86)

Defensive (-0.74)Harm Avoiding (-0.55)

Seeks Help and Advice (-0.55)Shows Leadership (0.53)

Meek (-0.47)

Compulsive (0.79)Orderly (0.75)

Enduring (0.70)Seeks Definiteness (0.50)

Intellectually Curious (0.78)Liberal (0.60)

Intelligent (0.59)Approval Seeking (0.57)

Aesthetically Sensitive (0.56)Objective (0.46)

Supporting (0.42)

AgreeablenessEmotional Stability ConscientiousnessExtraversion Openness

The GFP and the Big Five from 29 Self-Rating Scales

.44

.36

.29

1.00

.38

.93

- .39

.72

-.47

.59

.69

GFP

Activity

Extraversion

Empathy

Emotional Stability

Trust

Mental Toughness

Orderliness

Conformity

Conscientiousness

Empathy

Extraversion .54

0.64

GFP in Comrey Personality Scales

.52

.65

.71

.64

.58

.48

.14

.86

.26

.23

Alpha

Beta

Gamma

.70

.47

.92

.86 .45

-.88 .24

.65 .99

.31 .78 .50

.27

.25 .33

-.42 .76

.63

.75

.58

Schizophrenia

Social Introversion

Psychasthenia

Hysteria

Hypochondriasis

Depression

Masculinity/Femininity

Psychopathic Deviate

Paranoia

Hypomania

.26

.10

.16

.13

.00

.32

.92

.49

.67

.32

.61

.70

.55

.44

Plasticity

GFPStability

Delta

.99

GFP in MMPI-2

GFP

Plasticity

Stability

Social Potency

Social Closeness

Well-being

Alienation

Aggression

Achievement

Control

Harm Avoidance

Traditionalism

Absorption

.01

.76

.37

.56

.72

.62

.55

.78

.89

.59

Stress Reaction .01

Extraversion

Agreeableness

Conscientiousness

Emotional Stability

Openness to Experience

.50

.50

-.19 -.45

.99

1.00

.74

.21

.99 .22 .23

.47

-.53 .46

-.67

.66.45

-.39

.40

.61

.33

.67

.29

-.35

-1.00

.12

.21

.20

.15

.14

GFP in MPQ

.32

General Factor of Personality (GFP)

High Low Emotionally stable Neurotic Agreeable Disagreeable Conscientious Careless Extraverted Introverted Intellectually open Closed-minded Pro-social A-social Sense of well-being Alienated, angry Satisfaction with life Dissatisfied with life High self-esteem Low self-esteem Positive outlook Negative outlook

Emotional Intelligence Personality Disorders