Individual Differences and Personality

Flashcards covering personality theories, statistical measurements (z-scores, reliability, validity), biological models, evolutionary psychology, personality disorders, and mental abilities including the Big Five, HEXACO, and intelligence factors.

Idiographic approach

An approach that provides insights into the distinctive characteristics of an individual's personality but is often inefficient and based on small groups.

Nomothetic approach

An approach that allows for the discovery of general laws regarding personality, moving from general patterns to specific individuals.

Z-score

A standard score calculated as $(x - \mu) / \sigma$ where the mean is $0$ and the standard deviation is $1$.

T-score

A standard score where the average is $50$ and the standard deviation is $10$.

Internal consistency

Reliability related to error in items, depending on the number of items and the correlation between them, often represented by Cronbach's $\alpha$.

Inter-rater reliability

The proportion of variance in total ratings that corresponds to the agreement between different observers.

Test-retest reliability

A measure of consistency over time; low scores may indicate traits that change quickly, such as emotions.

Spearman-Brown formula

A formula for testing internal consistency where $\text{k}$ is the number of items and $\text{r}$ is the correlation between items.

Content validity

The requirement that items assess all characteristics of the intended trait and none of the irrelevant ones.

Construct validity

The degree to which a measurement actually measures the intended theoretical concept, such as intelligence.

Convergent validity

A type of construct validity investigating the correlation with variables measuring similar or opposite characteristics.

Discriminant validity

A type of construct validity investigating the extent to which a scale is unrelated to variables measuring different characteristics.

Criterion validity

The relationship between a measurement and a specific outcome or prediction.

Self-report

A structured and objective measurement method where everyone receives the same questions and fixed answer options; accuracy depends on self-knowledge and willingness to report.

Biodata

Objective information about a person's life history, such as grades or phone usage, which represents life milestones.

Mischel's conclusion

The argument that personality traits are not useful for predicting behavior because behavior related to the same trait often shows weak correlations across situations.

Aggregation

The process of averaging behavioral observations over many situations to demonstrate consistency that may not be visible in only two situations.

Factor loading

The correlation between a specific item and a factor in factor analysis.

Lexical hypothesis

The theory that the most important personality traits for communication are encoded in a language's dictionary (lexicon).

The Big Five

A personality model consisting of Extraversion, Agreeableness, Conscientiousness, Emotional Stability (vs. Neuroticism), and Intellect/Imagination.

HEXACO model

A model that includes six factors: Honesty-Humility, Emotionality, Extraversion, Agreeableness, Conscientiousness, and Openness to Experience.

Social investment hypothesis

The theory that individuals develop a more mature personality in response to the demands of adult social roles.

Biological maturation

Personality changes caused by genetic shifts involving hormones, neurotransmitters, and brain structures.

Sanguine

One of the four humors described by Hippocrates and Galen, associated with excess blood and a cheerful temperament.

Melancholic

One of the four humors associated with black bile and a depressive temperament.

Choleric

One of the four humors associated with yellow bile and a hot-tempered/irritable temperament.

Phlegmatic

One of the four humors associated with phlegm and a calm/steady temperament.

Somatotypes

William Sheldon's classification of body types into endomorph (fat), mesomorph (muscular), and ectomorph (slender), linked to personality traits.

Dopamine

A neurotransmitter promoting reward signals; high levels are linked to novelty-seeking behavior in Cloninger's theory.

Serotonin

A neurotransmitter that inhibits pain signals; low levels are linked to higher scores in 'harm avoidance' according to Cloninger.

Behavioral activation system (BAS)

Also known as the go-system; brain areas responsible for receiving signals indicating that rewards are being experienced.

Behavioral Inhibition System (BIS)

Also known as the stop-system; brain areas responsible for the avoidance of punishment.

Ascending Reticular Activating System (ARAS)

Eysenck's proposed brain mechanism that acts as a filter for stimuli; low stimulation leads to a search for extra stimuli in extraverts.

Intraclass correlation coefficient

The correlation between family members on a specific trait, used to study nature versus nurture.

Additive genetic effects

Effects where each gene contributes separately to increasing or decreasing the level of a personality trait.

Genotype-environment correlation

When genes lead individuals to experience specific environments, categorized as passive, reactive/evocative, or active.

Fluctuating optimum

An evolutionary mechanism where the ideal level of a trait varies depending on environmental conditions over time and place.

Frequency-dependent selection

An evolutionary mechanism where trait variation is maintained because no single ideal level exists, but rather an ideal balance of different levels in a population.

Reciprocal altruism

Altruism where the benefit comes from the expectation that the recipient will return the behavior later.

Kin altruism

Altruism where the benefit comes from helping others who share a portion of the same genes.

Comorbidity

A situation where two personality disorders have overlapping symptoms and are frequently diagnosed together.

Psychodynamic psychotherapy

A treatment focused on helping the patient reflect on their mental life and emotions to increase self-insight.

Cognitive Behavioral Therapy (CBT)

A treatment that identifies and corrects irrational beliefs or inappropriate views held by the patient.

Dark Triad

A group of three traits—psychopathy, Machiavellianism, and narcissism—that all correlate strongly negatively with Honesty-Humility.

Factor g

General intelligence; a single factor of mental ability identified by Charles Spearman that influences performance across different tasks.

Eduction of relations and correlates

The ability to discover relationships between elements and derive new connections, typical of high $g$-loading tasks.

Fluid intelligence

The ability to solve new or novel problems, such as puzzles or riddles.

Crystallized intelligence

Mental ability based on familiar or learned tasks, such as vocabulary or school subjects.

Flynn effect

The observed increase in fluid intelligence scores in the population over recent decades.

Triarchic Theory of Intelligence

Robert Sternberg's model consisting of three aspects: analytical, creative, and practical intelligence.

Emotional Intelligence (EQ)

The ability to monitor, distinguish, and use emotional information as a guide for thinking and acting.