Psy 121.3 Lecture 1 20250226

From Schacter 2023

Personality comes from the Greek (by way of Latin) : per + sonare = to speak through the mask.

(Greek actors wore masks on stage to portray characters).

Schacter defines personality as an individual’s characteristic style of behaving, thinking

and feeling. Note how difficult it is to measure the last two qualities.

There are four main approaches to the study of personality: biological; psychodynamic;

humanistic-existential; social-cognitive.

This class will focus on the neuroscientific approach, which begins

by asking the question: “What is a self?”

A possible answer: The mask that filters our motivations and thoughts is the dorsolateral prefrontal cortex, that part of the frontal lobe that is active during fully awake periods and also during lucid dreams.

A possible answer: The mask that filters our motivations and thoughts is the dorsolateral prefrontal cortex, that part of the frontal lobe that is active during fully awake periods and also during lucid dreams.

Measuring Personality

A self-report is defined as a questionnaire method in which as person provides subjective

information about his/hers thoughts, feelings and behaviors.

The most common method of personality assessment is the self-report. The self-report scale is

created by collecting sets of self-descriptive statements that indicate different degrees of a

personality characteristic, such as ‘friendliness’.

A good example is the Ten Item Personality Inventory (TIPI) (Gosling, Rentfrow & Swann,

2003) Adding up the number of statements the person endorses that indicate ‘friendliness’ and

subtracting those statements that indicate ‘unfriendliness’ will yield a measure of the person’s

self-reported friendliness.

Such scales are: (1) overall happiness (Lyubomirsky, 2008); rapid response to insults (Swann &

Bentfrow, 2001).

REQUIRED FOR MIDTERM 2

Minnesota Multiphasic Personality Inventory

This is the premier personality assessment tool; its present form is the MMPI-2-RF.

The MMPI-2-RF consists of 338 self-descriptive statements to which the respondent answers

“true, false, cannot say”.

The MMPI-2-RF measures a wide range of psychological constructs, clinical problems (for

example, antisocial behaviour, thought dysfunction), somatic (body) problems such as head

pains, internalizing problems such as anxiety or self-doubt, externalizing problems (aggression,

substance abuse), and interpersonal problems (family problems, avoidance).

The MMPI-2-RF also includes a validity scale that measures a person’s attitudes towards test-

taking and any tendency to distort the results by faking answers.

The MMPI-2-RF is analyzed based on empirical criterion keying; that means measuring this

individual score against hundreds of thousands of tests in a database. For example, the MMPI-2-

RF scores will measured against incarcerated criminals, and conversely medical professionals.

This approach--measuring against real-world cases--is what gives the MMPI-2-RF its construct

validity. Note: google “define: construct validity” to understand the importance of the term.

Accurate measurement of personality will only occur if people provide accurate responses. Many

people have a tendency to respond in a socially desirable way--demand characteristics--others

have aspects of themselves they know nothing about, they may be inaccurate about past

experiences, or what factors are motivating their behaviour in the present (Wilson, 2009).

Example: Sensitive to Feedback: dejected when a friend cancels dinner plans; elated when a

stranger returns a smile; ashamed after receive a poor work evaluation.

Neuroticism

Anxious Low self-esteem Moody Shy

Cries easily Sensitive to feedback Quick to anger

REQUIRED FOR MIDTERM TWO

The Big Five Factor Model

Openness to experience High: imaginative; variety;

independent

Low: down-to-earth; routine;

conforming

Conscientiousness High: organized; careful; self-

disciplined

Low: disorganized; careless;

weak-willed

Extraversion High: social; fun-loving;

affectionate

Low: retiring; sober; reserved

Agreeableness High: soft-hearted; trusting;

helpful

Low: ruthless, suspicious;

uncooperative

Neuroticism High: worried; insecure; self-

pitying

Low: calm; secure; self-

satisfied

The Big Five dimensions are so universal that they show up even when people are asked to

evaluate complete strangers (Passini & Norman, 1966). The reality of these traits has been

clearly established: people high in extraversion choose to spend time with other people; people

high in conscientiousness generally perform well at work and live longer; people low in

conscientiousness are more likely than average to be juvenile delinquents. (John & Srivastava,

1999).

REQUIRED FOR MIDTERM TWO

Brain and Personality

When someone experiences a profound change in personality, testing often reveals the presence

of brain pathologies such as stroke, brain tumour, or changes consistent with dementia (Feinberg,

2001). The administration of antidepressant medication and other pharmaceutical treatments that

can change brain chemistry can also trigger personality changes, making people somewhat more

extraverted and less neurotic (Bagby et al., 1999)

In one review of studies involving over 24,000 twin pairs, identical twins proved markedly more

similar to each other in personality than did fraternal twins. (Loehlin, 1992). Heritability

coefficents indicate that roughly half of the variability among individuals results from genetic

factors (Bouchard & Loehlin, 2001).

Heritability Estimates for the Big Five Personality Traits

Trait Dimension Heritability

Openness 0.45

Conscientiousness 0.38

Extraversion 0.49

Agreeableness 0.35

Neuroticism 0.41

Source Loehlin, 1992

REQUIRED FOR MIDTERM TWO

Gender Differences in Personality

Examples: Males are more physically aggressive than females, but females engage in more

relational aggression than do males, even from a very young age (Crick & Grotpeter, 1995).

On the Big Five, studies across dozens of cultures around the world show that women are higher

on neuroticism, extraversion, agreeableness, and conscientiousness; in terms of openness,

women report more to feelings and men to ideas. (Schmitt et al., 2008). Overall, however men

and women are far more similar in personality than they are different. (Hyde, 2005).

Genetics and Personality

Can genetics predict specific behaviours? Martin et al., 1986 examined 3000 pairs of identical

and fraternal twins and found genetic evidence for transmission of conservative views on

socialism, church authority, the death penalty, and mixed-race marriage. A set of interacting

genes is the likely culprit.

Hatemi et al, 211 reported that after examining the DNA of 13,000 people found associations

between conservative/liberal and the chromosomal regions linked to mental flexibility.

Are traits hard-wired in our brains? Hans Eysenck suggested that extraverts pursue stimulation

because their reticular formation is not easily aroused. To feel greater cortical arousal, extraverts

seek out more social interaction. In contrast, introverts prefer quiet activities like reading because

their cortex is more easily stimulated to optimal arousal.

It boils down to concentration. Extraverts tend to perform well at tasks that are done in a noisy,

arousing context, whereas introverts are better at tasks that require concentration in tranquil

contexts.

Jeffrey Grey proposed the dimensions of extraversion-introversion and neuroticism reflect two

basic brain systems: (1) a behavioral activation system; (2) a behavioral inhibition system.

Studies of brain electrical activity (quantitatve EEG) and functional brain imaging (fMRI) that

the individual differences in activation and inhibition arise from the interaction of these two

systems. (DeYoung & Grey, 2009).

Also, the volume of a brain region may correlate to the particular self-reported personality trait.

For instance, self-reported neuroticism is correlated with brain regions involved with sensitivity

to threat. (DeYoung et al., 2010)

REQUIRED FOR MIDTERM TWO

Self-Concept in the Brain

Self-relevance occurs when those traits people use to judge themselves stick in memory. When

people make judgments of themselves on traits, they later recall these traits better than when they

judge other people on the same traits. (Rogers, Kuiper & Kirker, 1977).

In studies of the this effect of self-relevance on memory, researchers using brain imaging

techniques have found that the simple activity of making judgments about the trait self-concept is

accompanied by the activation of the medial prefrontal cortex. (Figure 12.5)