Psychobiological & lexical approaches to personality:

Enter the matrix

Psychobiological & lexical approaches to personality:

Enter the matrix

Dr Niko TiliopoulosRoom 448, Brennan McCallum building

Email: nikot@psych.usyd.edu.au

Assumptions of the Traits Assumptions of the Traits approach Iapproach I

Personality Personality existsexists!!

Personality is a probabilistic and dynamic systemPersonality is a probabilistic and dynamic system

Personality has both quantity and quality propertiesPersonality has both quantity and quality properties

Systematically describes differences between (and within) Systematically describes differences between (and within) individualsindividuals

Emphasises the need of a Emphasises the need of a useful useful scientific taxonomyscientific taxonomy

Personality is the dynamic & organised set of Personality is the dynamic & organised set of characteristics possessed by a person that characteristics possessed by a person that uniquely influences her or his cognitions, uniquely influences her or his cognitions,

motivations, attitudes, behaviour, and psychology motivations, attitudes, behaviour, and psychology as a wholeas a whole

Assumptions of the Traits approach IIAssumptions of the Traits approach II

Personality develops through the interplay between:Personality develops through the interplay between:

– CognitionCognition (memory, perception, thought, language, intelligence) (memory, perception, thought, language, intelligence)

– TemperamentTemperament (characteristic reaction patterns, present from an early age)(characteristic reaction patterns, present from an early age)

– Constitution or physiologyConstitution or physiology (neurology, endocrinology, genetics, etc.) (neurology, endocrinology, genetics, etc.)

– EnvironmentEnvironment (both human and physical) (both human and physical)

The Personality pie The Personality pie (an evidence-based (an evidence-based

representation)representation)

Non-shared Non-shared environmentenvironment

Shared Shared environmentenvironment

50%50%

10%10%

40%40%

BiologyBiology

geneticsgenetics

• Unique experiences

• Diseases

• Accidents

• Diet

• Lifestyle

• Aspirations/Motives

• Religiosity/Spirituality

• Choices

• Chance!

• Unique experiences

• Diseases

• Accidents

• Diet

• Lifestyle

• Aspirations/Motives

• Religiosity/Spirituality

• Choices

• Chance!

• Family

• Socialisation

• Schooling

• Culture

• Religion

• Evolution

• Family

• Socialisation

• Schooling

• Culture

• Religion

• Evolution

• Neurotransmitters

• Brain systems

• Hormones

• Nervous system

• Age

• Sex

• Genes

• Evolution

• Neurotransmitters

• Brain systems

• Hormones

• Nervous system

• Age

• Sex

• Genes

• Evolution

Assumptions of the Traits approach IIIAssumptions of the Traits approach III

The building blocks of personality are called The building blocks of personality are called TraitsTraits

Traits are Traits are ““general dispositions that people possess that general dispositions that people possess that uniquely influence their psychologyuniquely influence their psychology””

– E.g. outgoing, impulsive, anxious, sociable, hostile, optimistic, altruisticE.g. outgoing, impulsive, anxious, sociable, hostile, optimistic, altruistic

Every human possesses Every human possesses ALLALL traits, but not at the same intensity (or centrality) traits, but not at the same intensity (or centrality)

Their development is assumed to end in early adulthoodTheir development is assumed to end in early adulthood

They are They are relatively stablerelatively stable over time and situation over time and situation– TraitsTraits vs. vs. StatesStates

Personality is Personality is dimensionallydimensionally and and hierarchicallyhierarchically arranged arranged

The hierarchical arrangement of personalityThe hierarchical arrangement of personality

Specific (situational) responsesSpecific (situational) responses

Habitual responses (habits)Habitual responses (habits)

Temperament (biologically-based)Temperament (biologically-based)

Traits(e.g. pessimistic, aggressive, reliable)

Traits(e.g. pessimistic, aggressive, reliable)

Personality dimensions(e.g. neurotic, psychotic, conscientious)

Personality dimensions(e.g. neurotic, psychotic, conscientious) More stable

Simpler

Complex

Less stable

Fewer dimensions

(higher level of dimensionality)

More dimensions

(lower level of dimensionality)

1. Stability

2. Complexity

3. Dimensionality

1. Stability

2. Complexity

3. Dimensionality

ExtravertExtravert

ImpulsiveImpulsive ActiveActive LivelyLively

TemperamentTemperamentTemperamentTemperament TemperamentTemperament

HabitHabitHabitHabit

SituationSituationSituationSituation ← Tendency to socialise or act on impulse

← Group-activities, leader, extreme sports, careless, promiscuous

← Differential cortical & dopaminergic activation

How does the Traits approach How does the Traits approach discoverdiscover personality?personality?

(Common) assumptions:(Common) assumptions:

– The personality The personality spacespace is made up of is made up of dimensionsdimensions

– These dimensions tend to be These dimensions tend to be independentindependent from each other from each other

– These dimensions are These dimensions are finitefinite

– We can discover these dimensions by We can discover these dimensions by decomposing the personality matrixdecomposing the personality matrix!!

StatisticsStatistics– Factor analysisFactor analysis

Two main traits typologiesTwo main traits typologiesThe The Lexical taxonomyLexical taxonomy (the (the Big-5Big-5))

(seeks to identify trait-descriptors in natural language)(seeks to identify trait-descriptors in natural language)

– Neuroticism:Neuroticism: E Emotional stabilitymotional stability

– Extraversion:Extraversion: Having a social impact Having a social impact

– Agreeableness:Agreeableness: M Maintaining positive relations with othersaintaining positive relations with others

– Conscientiousness:Conscientiousness: Responsibility and will to achieve Responsibility and will to achieve

– Openness:Openness: Artistic tendencies, intellect, being open to new ideas or change Artistic tendencies, intellect, being open to new ideas or change

The The Psychobiological taxonomyPsychobiological taxonomy (the (the Big-3Big-3))(seeks to identify the biological/genetic markers of traits)(seeks to identify the biological/genetic markers of traits)

– NeuroticismNeuroticism (related temperament: (related temperament: emotionalityemotionality))A predisposition to mood and anxiety disordersA predisposition to mood and anxiety disorders

– ExtraversionExtraversion (sociability and impulsivity) (sociability and impulsivity)A predisposition to accidents and injuriesA predisposition to accidents and injuriesIt mediates the psychopathological effects of the other two dimensionsIt mediates the psychopathological effects of the other two dimensions

– PsychoticismPsychoticism ((tough- vs. tender-mindednesstough- vs. tender-mindedness))A predisposition to psychotic disordersA predisposition to psychotic disorders

ContributionsContributionsScientific theories that are evidence-basedScientific theories that are evidence-based

Clear-cut predictionsClear-cut predictions

TestableTestable

Cross-cultural validityCross-cultural validity

Occupational/educational psychologyOccupational/educational psychology

Psychopathology (the foundation of Psychopathology (the foundation of Clinical PsychologyClinical Psychology))

Evolutionary (personality) psychologyEvolutionary (personality) psychology & & Animal psychologyAnimal psychology

Forensic psychology & criminal profilingForensic psychology & criminal profiling

CriticismCriticismHow many traits or dimensions?How many traits or dimensions?

Heavily dependent on statisticsHeavily dependent on statistics

Heavily dependent on self-reportsHeavily dependent on self-reports

When assessment is based on medical When assessment is based on medical methods it is impracticalmethods it is impractical

Actually, do traits exist at all?Actually, do traits exist at all?

Some famous individuals that exemplify trait Some famous individuals that exemplify trait characteristicscharacteristics

Trait descriptionTrait description Famous individualFamous individual

HighHigh LowLow HighHigh LowLowAssertive, Assertive, dominantdominant

Humble, Humble, cooperativecooperative

Genghin KhanGenghin Khan JesusJesus

Conscientious, Conscientious, persistentpersistent

Expedient, Expedient, undisciplinedundisciplined

Mother TeresaMother Teresa CasanovaCasanova

Tense, drivenTense, driven Relaxed, tranquilRelaxed, tranquil MacbethMacbeth BuddhaBuddha

Tough-minded, Tough-minded, self-reliantself-reliant

Tender-minded, Tender-minded, sensitivesensitive

James BondJames Bond Robert BurnsRobert Burns

Self-sufficient, Self-sufficient, resourcefulresourceful

Group-dependent, Group-dependent, affiliativeaffiliative

CopernicusCopernicus Marilyn MonroeMarilyn Monroe

Controlled, Controlled, compulsivecompulsive

Undisciplined, laxUndisciplined, lax Margaret ThatcherMargaret Thatcher Mick JaggerMick Jagger

Venturesome, Venturesome, socially boldsocially bold

Shy, retiringShy, retiring ColumbusColumbus Sylvia PlathSylvia Plath

Main traits theoristsMain traits theorists

Gordon AllportGordon Allport (1897 - 1967) (1897 - 1967)Raymond CattellRaymond Cattell (1905 - 1998) (1905 - 1998)Hans EysenckHans Eysenck (1916 - 1997) (1916 - 1997)Jeffrey Alan GrayJeffrey Alan Gray (1934 - 2004) (1934 - 2004)Marvin ZuckermanMarvin Zuckerman (1928 - ) (1928 - )Kim BartholomewKim Bartholomew (?) (?)Claude Robert CloningerClaude Robert Cloninger (1944 - ) (1944 - )Theodore MillonTheodore Millon (1928 - ) (1928 - )Cindy HazanCindy Hazan (?) (?)David BussDavid Buss (1953 - ) (1953 - )Samuel GoslingSamuel Gosling (?) (?)