Personality and Individual Differences: Psychological Measurement 3

Personality Traits and Inventories

Defining Personality Traits

To understand personality, we must define what a personality trait is. Personality is not just a single behavior but a complex combination of behaviors.

Ashton's Conceptual Definition:

A personality trait refers to differences among individuals in a typical tendency to behave, think, or feel in some conceptually related ways, across a variety of relevant situations and across some fairly long periods of time. This definition can be broken down into key elements:

  • Differences Among Individuals: Personality descriptions involve comparing individuals, highlighting characteristics with a wide range of differences.

  • Typical Tendency to Behave, Think, or Feel: Personality describes the likelihood of certain behaviors, thoughts, or feelings.

  • Example: An extroverted person is likely to attend parties and enjoy meeting people but not necessarily all the time.

  • Conceptually Related Ways: Traits are expressed through various behaviors that have a common psychological element.

  • Example: Neuroticism includes selfishness, being easily scared, and insecurity, potentially linked to biological factors.

  • Across a Variety of Relevant Situations: Behaviors should be consistent across different settings, such as school, sports clubs, and social gatherings.

  • Example: An extroverted person should exhibit extroverted behaviors in various environments.

  • Across Some Fairly Long Periods of Time: Personality traits are stable over time. If someone is agreeable, they are expected to remain so over weeks, months, or years.

  • Example: Extroversion should be a relatively consistent trait over time for an individual.

Personality Traits vs. Other Psychological Characteristics

Other psychological characteristics are not personality traits:

  • Mental abilities

  • Attitudes

Personality traits may predict attitudes, but they are distinct. Traits are not mental abilities or aptitudes.

Do Personality Traits Exist? Controversies

Criticism of personality traits has a long history.

  • Hartshorne and May Study:

    • Investigated 11,000 children for consistency in moral character (altruism, self-control, honesty).

    • Observed behavior in various situations (charity donations, cheating on tests, self-control with food).

    • Found little consistency between behaviors; correlation of only 0.2.

  • Walter Mischel's Situationist Argument:

    • Argued that individual differences depend more on the specific situation than on personality traits.

    • Example: Conscientiousness depends on the situation. Crossing a red light depends on whether it's the middle of the night or day with a police officer present.

    • Claimed that personality traits have limited value for predicting behavior.

Rebuttal to the Criticism

The claim that situations determine behavior does not fully hold because this research often fails to demonstrate cross-sectional consistency and aggregate behaviors.

  • Aggregation of Behaviors:

    • Collecting and aggregating behaviors across different settings and times can provide a good description of a person’s behavior.

    • Correlations between aggregated behaviors can be high (e.g., 0.5).

Personality is reflected in overall typical behaviors observed across many situations, not just one specific situation.

  • Sampling Behaviors:

    • Criticisms often stem from not sampling enough behaviors, situations, or time.

    • Personality determines the likelihood of showing different behaviors across time and situations, and not one specific behavior.

Michel's research was important in showing that personality and situations interact. If a situation is open (e.g., little traffic, no police), personality may play a role in determining behavior.

Widely Used Personality Inventories

  • California Psychological Inventory (CPI):

    • An older questionnaire with approximately 400 items.

    • Aims for broad personality description and is based on the Minnesota Multiphasic Personality Inventory (MMPI).

  • Eysenck Personality Questionnaire (EPQ):

    • Measures three dimensions: neuroticism, extroversion, and psychoticism.

    • Based on a biological model.

  • Temperament and Character Inventory:

    • Developed by Cloninger and colleagues.

    • Another biologically based model.

Personality Inventories to Avoid

  • Myers-Briggs Type Indicator (MBTI):

    • Classifies people into types (e.g., extrovert).

    • Crude measure that doesn't indicate the degree of extroversion or other characteristics.

    • Lacks scientific validity and reliability.

    • Limited evidence that it predicts anything.

    • Not scientifically sound in theory and methods.

The Big Five Framework

The Big Five Framework consists of five major dimensions of personality:

  1. Neuroticism

  2. Extroversion

  3. Openness to Experience

  4. Agreeableness

  5. Conscientiousness

  • Measures:

    • Big Five Inventory (BFI): 44 items

    • NEO Five-Factor Inventory (NEO-FFI): 60 items

    • NEO Personality Inventory Revised (NEO PI-R): 240 items

To remember the Big Five dimensions, you can use the acronym OCEAN (Openness, Conscientiousness, Extraversion, Agreeableness, Neuroticism).

HEXACO Personality Inventory

The HEXACO Personality Inventory was developed by Lee and Ashton. HEXACO stands for:

  • Honesty-Humility (H)

  • Emotionality (E)

  • Extraversion (X)

  • Agreeableness (A) versus Anger

  • Conscientiousness (C)

  • Openness to Experience (O)

This model includes the H factor (Honesty-Humility), which Lee and Ashton believed was missing from the Five-Factor Model.

Strategies for Personality Inventory Construction

There are three main strategies for constructing personality inventories:

  1. Empirical Strategy:

    • Collects items that have empirical relationships with the trait of interest.

    • Example: Using the item "I like to eat red meat" as a sign of masculinity because men tend to eat more red meat than women.

    • Not used much anymore due to unclear relationships between behaviors and characteristics.

  2. Factor Analytic Strategy:

    • Collects a large pool of items and uses factor analysis to find groups of items that measure different traits.

    • Used to develop the Big Five inventories.

  3. Rational Strategy:

    • Writes items based on theory, experience, and research that describe the trait.

    • Example: The Multidimensional Perfectionism Scale by Hewitt and Flett.

    • Researchers develop items that describe aspects of perfectionism.

Eysenck and Cloninger's biological models use a strategy combining empirical and rational elements.

Summary

  • The study of personality traits requires an understanding of personality traits

  • The Person vs. Situation debate involves seeing individual behaviors, and single behaviors are not well predicted by personality.

  • Widely used structured personality inventories include the EPQ, Big Five questionnaires, and the HEXACO.

  • The three main strategies of personality inventory construction are the empirical, factor analytic, and rational strategies.