Biological Determination of Personality: Temperament

Comprehensive vocabulary flashcards covering historical, physiological, genetic, and clinical models of temperament and personality from the First Faculty of Medicine lecture series.

Temperament

Psychological characteristics that are innate and hereditary, possess an identifiable biological basis, and govern the formal style, dynamics, and temporal course of behavior (the 'how' rather than the 'what' or 'why').

Character

The self-regulatory and intentional dimensions of behavior that develop through learning and reflection, encompassing conscious goals, values, and self-evaluations (such as self-directedness and cooperativeness).

Phineas Gage

A railroad construction foreman who survived an 1848 accident where a tamping iron pierced his orbitofrontal cortex; though his intellect stayed intact, his personality shifted from reliable and sociable to moody, impulsive, and irresponsible, marking the first documented case linking focal brain damage to personality change.

Ancient Humoral Theory

A doctrine attributed to Hippocrates and systematized by Galen stating that human health and psychic disposition depend on the balance ('temperare') of four bodily humors: blood, phlegm, yellow bile, and black bile.

Sanguine

The temperament associated with blood; characterized by being lively, mobile, quick to react, easily adaptable to setbacks, and inclined toward varied impressions.

Phlegmatic

The temperament associated with phlegm; characterized by a slow, calm, steady disposition, uniform drive, and understated outward expression of psychological states.

Choleric

The temperament associated with yellow bile; characterized by fast, intense reactions, capacity for passionate commitment, emotional volatility, and sudden affective swings.

Melancholic

The temperament associated with black bile; characterized by being easily hurt, deeply responsive to minor events internally, yet displaying weak outward reactivity to the surrounding environment.

Phrenology

Franz Joseph Gall's 19th-century theory asserting that specific behavioral tendencies and mental faculties are localized in discrete brain regions, inferable through the examination of cranial bumps.

Pyknic Type

Kretschmer's rounded, medium-height body type with short limbs and a tendency toward fat accumulation; tied to a cyclothymic temperament (fluctuating between cheerfulness and sadness) and a predisposition to cyclophrenia (bipolar affective psychosis).

Leptosomic Type

Kretschmer's tall, slender physique marked by low body weight relative to stature; linked to a schizothymic temperament (oscillating between hypersensitivity and emotional apathy, rich inner fantasy) and schizophrenia.

Athletic Type (Kretschmer)

Kretschmer's robust bodily build characterized by strong musculature and bone structure with minimal body fat; tied to a viscous temperament (tenacious, slow, alternating between explosiveness and apathy) and epilepsy.

Endomorph

Sheldon's somatotype characterized by a rounded, soft, fat-prone build; corresponds to a viscerotonic temperament that is emotion-guided, highly sociable, and people-oriented.

Mesomorph

Sheldon's somatotype characterized by an angular, firm build with heavy musculature and large bones; corresponds to a somatotonic temperament that is assertive, athletic, low in sensitivity, and prone to aggression.

Ectomorph

Sheldon's somatotype characterized by a tall, lean body and large cranial proportions; corresponds to a cerebrotonic temperament that is introverted, emotionally restrained, and reclusive.

Pavlovian Properties of the Nervous System

Three physiological characteristics of nervous systems identified in dogs: strength (endurance under intense or sustained stimulation), balance (equilibrium between excitation and inhibition), and mobility (speed of transitioning between excitation and inhibition).

Goodness of Fit

A developmental concept formulated by Thomas and Chess describing harmony when an individual's innate temperament aligns with environmental demands and parental expectations.

Poorness of Fit

Thomas and Chess's term for discordance between a child's temperamental disposition and environmental demands, significantly increasing the probability of maladaptive emotional and behavioral outcomes.

Easy Temperament

Thomas and Chess's pediatric cluster characterized by regular biological rhythms, open and positive reactions to novel stimuli, quick adaptability to environmental change, and a predominantly mild, positive mood.

Difficult Temperament

Thomas and Chess's pediatric cluster characterized by irregular biological routines, withdrawal or negative reactions to new stimuli, slow adaptability, and intense, frequently negative emotional expressions.

Slow-to-Warm-Up Temperament

Thomas and Chess's pediatric cluster marked by mild negative reactions to novelty and initial withdrawal, accompanied by slow, gradual adjustment through repeated, unpressured exposure.

EAS Theory

A genetic temperament model developed by Buss and Plomin positing that early-appearing, stable, and highly heritable traits consist of three dimensions: Emotionality, Activity, and Sociability.

Activity (EAS Model)

A physical energy expenditure dimension defined entirely by bodily movement rather than cognition; divided into four facets: tempo (speed), vigor (force), endurance (duration), and the continuous urge to move.

Emotionality (EAS Model)

The propensity to become readily distressed or fearful accompanied by pronounced autonomic arousal (e.g., tachycardia, diaphoresis); Buss and Plomin count solely negative affect within this dimension.

Sociability (EAS Model)

The intrinsic motivational drive to affiliate and be in the company of others as opposed to remaining solitary, distinct from interpersonal competence or social skill.

Inhibited Temperament

Jerome Kagan's behavioral profile identified in infants and young children featuring motor tension, avoidance, distress toward unfamiliar stimuli, prolonged latency to relax, and high limbic reactivity.

Uninhibited Temperament

Jerome Kagan's behavioral profile identified in young children featuring spontaneous curiosity, rapid relaxation, smiling, vocalizing easily, and approach behaviors toward novel stimuli and strangers.

PEN Model

Hans Eysenck's biologically anchored personality taxonomy comprising three supertraits: Psychoticism (P), Extraversion (E), and Neuroticism (N).

Eysenck's Quadrants

The integration of Galen's classical temperaments into modern trait psychology by crossing Extraversion (E) and Neuroticism (N): Melancholic (unstable introvert), Choleric (unstable extravert), Phlegmatic (stable introvert), and Sanguine (stable extravert).

Ascending Reticular Activating System (ARAS)

The brainstem network regulating cortical arousal in Eysenck's model; introverts have a higher baseline ARAS activity leading them to avoid high stimulation, whereas extraverts possess a lower baseline and seek external arousal.

Visceral Brain (Limbic System)

The emotional neural circuit whose activation threshold forms the biological substrate of Neuroticism (emotional lability) in Eysenck's theory and physiological reactivity in Kagan's inhibited temperament.

Gray's Rotated Dimensions (BIS and BAS)

Jeffrey Gray's theoretical realignment of Eysenck's axes by $45^{\circ}$, designating Impulsivity (Behavioral Activation System) and Anxiety (Behavioral Inhibition System) as the fundamental causal neuropsychological dimensions.

Behavioral Approach System (BAS)

Gray's neural substrate responding to appetitive stimuli and reward cues; regulates anticipatory pleasure and approach behavior via the mesolimbic dopamine pathway and striatum, predisposing to impulsivity.

Fight-Flight-Freeze System (FFFS)

The neuropsychological mechanism in Gray and McNaughton's revised model responding to conditioned and unconditioned aversive stimuli; mediates panic and defensive escape via the amygdala, hypothalamus, and periaqueductal gray.

Behavioral Inhibition System (BIS)

Gray's neuropsychological system activated by goal conflicts (e.g., approach-avoidance); coordinates risk assessment, hypervigilance, and anxiety through the septo-hippocampal formation and amygdala.

Harm Avoidance

Cloninger's temperament dimension modulated by serotonergic pathways; characterized when elevated by anticipatory worry, fear of uncertainty, shyness, and susceptibility to fatigue.

Novelty Seeking

Cloninger's dopaminergic temperament dimension characterized by impulsive behavior, active exploration, extravagance in rewards, and low tolerance for monotony.

Reward Dependence

Cloninger's noradrenergic temperament dimension reflecting responsiveness to social reinforcement, interpersonal warmth, sentimentality, and attachment.

Persistence (Cloninger)

Cloninger's temperament dimension characterized by sustained perseverance, perfectionism, high ambition, and continuous effort despite frustration or intermittent reinforcement.

Self-Directedness

Cloninger's primary character dimension representing individual agency, purposive goal pursuit, self-acceptance, and realistic problem-solving; an essential buffer against personality pathology.

Cooperativeness

Cloninger's character dimension encompassing social tolerance, empathetic perspective-taking, helpfulness, and social integrity.

Self-Transcendence

Cloninger's character dimension involving transpersonal identification, intuitive spiritual perspective, and experiencing oneself as an integral element of the wider universe.

Heritability ($h^2$)

A population-level statistical estimate indicating the proportion of observed phenotypic variance attributable to genetic variance among individuals, accounting for roughly $40\%$ of general personality variation.

Non-Shared Environment

Environmental factors and life experiences idiosyncratic to each sibling rather than shared across the family household, accounting for the majority of environmental variance ($\sim 60\%$) in adult personality.

Neuroplasticity

The biological capacity of neural systems and brain anatomy to undergo functional and structural remodeling in response to personal experiences, learning, and environmental demands.