Psychology Lecture 01: Types of Differences

Types of Differences

• Interindividual differences: variations between individuals in one or more traits, behaviors, or characteristics
• Intraindividual differences: differences that are observed within the same person when they are assessed at different times or in different situations

Important Terms

• Trait: enduring patterns of behavior and thought that are relatively consistent over time and across various situations
• Factor: a more-or-less enduring psychological characteristic that distinguishes one person from another and thus helps to define each person's individuality
• Dimension: a continuum from minimum to maximum intensity of a given feature
• Disposition: a construct used to describe the stability of human behavior over time
• Type: the dominant quality or qualities distinguishing a person or a group

Behavioral Genetics

• Study of the biological basis of individual differences
• B = f(GxE): behavior is a function of the interaction between genetic and environmental influences
• Phenotype: the expression of an individual's genes in behavioral traits that can be measured
• Phenotypic variance: the variation in behavioral traits that can be attributed to genetic and environmental influences
• Heritability estimate: a statistical indicator of the influence of genetic factors on individual differences in behavioral traits

Family Studies

• Comparing pairs of people with different degrees of relatedness
• Child shares genes (G) and environment (E) with parents

Temperament

• Has a biological basis
• Universally present
• Structured by several independent factors (e.g. extroversion, neuroticism, psychoticism)
• According to Eysenck, personality and temperament are synonymous, with temperament referring to the non-cognitive aspects of personality

Personality Structure Model

• Level of theoretical constructs (genotype) [L1]
• Level of phenomena that can be observed in laboratory conditions [L2]
• Level of traits resulting from the interaction of genotype and environment [L3]

Dimensions of Personality

• Extraversion: consists of features such as sociability, liveliness, activity, assertiveness, and sensation seeking
• Neuroticism: consists of features such as anxiety, depression, guilt, low self-esteem, and tension
• Psychoticism: directly related to pathology, including crime, psychopathy, and schizophrenia

Conditioning

• Introverts: generally easier to condition with unconditional stimuli of punitive nature
• Extroverts: generally faster to condition with unconditional stimuli of rewarding nature

Critical Remarks

• Undermining the primacy of dimensions of E and N
• Deviations in circadian patterns (I - higher arousal in the morning, E - higher arousal in the evening)
• Different levels of activity during the day

Inhibition Theory (Extraversion)

• Postulates: individuals differ in the speed and strength with which excitation and inhibition arise and in the speed with which inhibition disappears
• Individuals with weak, slowly developed excitation potential, with quickly rising strong reactive inhibition that disappears slowly, are predisposed to extraverted behavior patterns

Activation Theory (Extraversion)

• Source: the reticular system of the brain stem produces non-specific activation called cortical excitation, which is expressed in spontaneous electrical potentials of the brain
• The ascending reticular activating system (ARAS) is responsible for individual differences in E-I, which regulates the level of cortical activation in response to external and internal stimuli

Introduction to Personality

• Enduring characteristics and behavior that comprise a person's unique adjustment to life
• Construct used in order to explain the structure and development of personality

Allport Definition of Personality

• Dynamic organization within an individual, including mental systems that determine the individual's specific ways of adapting to the environment

Studies in Personality Psychology

• Nature and definition
• Development
• Structure
• Trait constructs
• Dynamic processes
• Variations (with emphasis on enduring and stable individual differences)
• Maladaptive forms

Temperament according to Trait Theory

• Starting point for personality shaping (includes basic and fundamental primary personality traits)
• Temperament includes personality traits that are present from early childhood
• Temperament includes those personality traits that have a biological basis

Costa & McCrae Criteria

• Presence of factors, manifested in stability, accuracy measured by the consistency of observers' opinions, and practical usefulness
• Prevalence, the fact of occurring in numerous forms in all cultures, races, regardless of gender and age
• Biological basis (usually limited to measurement based on the heritability index)

Big Five

• Openness to Experience: describes an individual's tendency to seek and positively evaluate life experiences, tolerance towards new things, and cognitive curiosity
• Conscientiousness: degree of organization, perseverance, and motivation in goal-oriented activities
• Extraversion: quality and quantity of social interactions, activity, energy, and the ability to feel positive emotions
• Agreeableness: positive vs negative attitudes towards other people, interpersonal orientation
• Neuroticism: emotional adjustment vs emotional imbalance

This quiz covers the basics of interindividual and intraindividual differences in psychology, with examples of how they are observed and studied.