The Psych Diaries

Key terms in personality assessment

Term	Definition
Reliability	The consistency of a test or measure by yielding similar results under consistent conditions
Validity	The extent to which a test measures what it claims to measure
Self-report inventory	A questionnaire where individuals rate their own personality traits
Performance-Based Measure	Assessment inferring personality from response to tasks or ambiguous stimuli. ie. projective tests
Interview	A method involving structured or open-ended questions to explore a person’s personality in depth.

Major Methods of Personality Assessment

Self report inventories

• Individuals answer questions about themselves
• Likert scales
• True/ false
• Efficient & easy to use
• Able to quantify traits to analyse the data
• Vulnerable to biases (social desireability, faking, low self awareness)

Performance-based measures

• Individuals response to ambiguous stimuli
• Inkblot test
• Thematic Apperception Test
• Indirectly assesses unconscious aspects of personality through inference
• Less subject to self bias
• Challenges with reliability & validity
• Lower inter-rater reliability
• Hard and time consuming to interpret results

Interviews & qualitative approaches

• Allows the exploration of unique experiences
• Rich data
• Honours the complexity of personality
• Multiple sources of data (verbal + non verbal)
• Labour intensive
• Subject to influence by interviewer effects

Reliability & validity in assessments

Reliability:

• Internal consistency (how well items on test measure the same construct)
• Inter-rater reliability (agreement between different assessors)
• Test- retest reliability (stability of results over time)

Why it’s important: helps us to know if changes in scores reflect real differences or just measurement erorrs

Validity:

• Construct validity (does test capture intended concept?)
• Convergent/divergent validity (does it relate to similar/different constructs as expected?)
• Discriminant validity (can it distinguish between groups?)
• Predictive validity (does it forecast relevant outcomes?)

Why it’s important: makes sure the test results can be used to draw meaningful conclusions

Challenges & Biases in Personality Assessment

Social Desirability & Faking

• People change their responses to appear more favourable
• Bending to fit expectations
• Affects accuracy of results

Memory & Insight Limitations

• Self-report measures rely on people’s ability to accurately understand themselves
• Memory errors and limited self awareness can lead to inaccurate responses

Interviewer Effects

• Behaviour and characteristics of interviewer can influence how participants respond
• Body language, tone, demographics
• Introduces variability

Cultural Bias

• Personality assessments may not be valid in all cultural contexts
• Values, language, norms shape how people interpret tests

Addiction: Substance vs Behavioural

Key Terms

Term	Definition
Additction	A chronic condition marked by compulsive engagement in rewarding stimuli, despite harmful consequences to health or functioning.
Substance Addiction	A pattern of using drugs or chemicals, such as alcohol or tobacco, where use continues despite significant negative outcomes.
Behavioural Addiction	A compulsion to engage in certain behaviours, like gambling or gaming, repeatedly despite negative impacts, without involving a substance.
DSM-5	The Diagnostic and Statistical Manual of Mental Disorders, used to define and diagnose mental health conditions, including addiction.

Substance vs Behavioural Addictions

Feature	Substance Addictions	Behavioural Addictions
Definition	Repeated use of drugs or chemicals despite harm	Compulsive engagement in behaviours despite harm
Examples	Alcohol, tobacco, opioids, stimulants, sedatives, cannabis	Gambling, gaming, shopping, internet use
Core Issue	Dependence on a substance	Dependence on a behaviour/activity
DSM-5 Status	Clearly defined and widely recognised	Gambling disorder recognised; others still debated
Symptoms	Cravings, loss of control, continued use despite harm	Compulsion, inability to stop, continued behaviour despite harm
Type of Symptoms	Cognitive, behavioural, and physiological	Mainly cognitive and behavioural
Biological Factor	Involves chemical effects on the body/brain	No external chemical, but similar brain reward activation
Impact on Life	Disrupts health, relationships, daily functioning	Disrupts health, relationships, daily functioning
Clinical Recognition	Well-established in clinical settings	Less established (except gambling)

Similarities

Shared Feature	Description
Compulsivity	Strong urge to engage in substance use or behaviour
Loss of Control	Difficulty stopping or reducing
Persistence Despite Harm	Continued use/behaviour even with negative consequences
Impact on Life	Affects relationships, health, and daily functioning
Reward System Activation	Similar brain reward pathways are involved

How common is addiction?

• Affects 1 in 20 Australians
• Most common: tobacco, alcohol, gambling, gaming

Neurobiology of Addiction

Brain Reward System

• Central to addiction
• Addictive substances/behaviours trigger release of pleasure chemicals
• This reinforces the behaviour (makes you want to repeat it)
• Over time, the system becomes hijacked
• The behaviour starts to feel necessary for survival

Consequences:

• Strong cravings
• Repeated use even when harmful
• Overrides rational thinking and self-control

Dopamine and Motivation

• Dopamine = key neurotransmitter in reward pathways
• Addictive behaviours cause dopamine surges
• Reinforces the desire to repeat the behaviour

Effects on behaviour:

• Motivation becomes focused on the addictive activity
• The behaviour becomes a top priority
• Other areas of life (relationships, responsibilities) are neglected

Neuroadaptation

• Brain changes structure and function with repeated exposure
• This process is called neuroadaptation

Key outcomes:

• Tolerance → need more of the substance/behaviour for same effect
• Withdrawal → negative symptoms when stopping
• Makes quitting much more difficult

Implications for Treatment

• Addiction is not just about willpower
• It involves both biological and psychological changes

Treatment approaches:

• Must address brain changes + behaviour
• Often requires comprehensive, multi-level interventions

Prevention & recovery:

• Understanding addiction helps develop better strategies
• Supports long-term recovery
• Emphasises that addiction is a medical and psychological condition, not just a choice

The ‘Addictive Personality’

Key Terms

Term	Definition
Addictive personality	A popular term suggesting some people have a fixed set of traits making them prone to addiction, often used in media, not science.
Addiction-prone personality	An early research concept proposing that certain personality profiles increase vulnerability to addiction, though not supported by consistent evidence.
Risk factor	A characteristic or condition that raises the likelihood of developing an addiction, but does not guarantee it will occur.
Homogenising	Treating all people with addiction as if they share the same personality profile, ignoring individual differences.

The evolution of the ‘Addictive Personality’

• 1950s–1960s- Early Research and ‘Addiction-Prone’ Personalities

  • Researchers proposed that some people are naturally more prone to addiction
  • Focus on identifying specific personality traits or weaknesses
  • Studies compared people with addictions vs. those without
  • Goal: find a clear “addictive personality” profile
• 1970s–1980s: Methodological Critiques and Lack of Evidence

  • Improved research methods led to criticism of earlier ideas
  • Little consistent evidence for a single addictive personality

  Key issues:

  • Cross-sectional studies → cannot determine cause vs. effect
  • Personality differences may be a result of addiction, not a cause

  Key finding:

  • Gendreau & Gendreau (1970):
    • No significant differences between addicts and non-addicts in:
      • Personality
      • Socioeconomic status
      • Life history
• 1990s–2000s: Popular Psychology and Self-Help Influence

  • Idea of an “addictive personality” became popular in media
  • Spread through:
    • Self-help books
    • Online quizzes
    • Pop psychology content

  Important note:

  • Popularity increased despite weak scientific evidence
• Present Day: Current Understanding and Debate

  • Most experts agree there is no single addictive personality
  • Shift toward understanding multiple risk factors

  Modern perspective:

  • Addiction is influenced by:
    • Personality traits (not a single type)
    • Environment
    • Biological factors
  • Emphasis on complex interactions, not simple labels
  • Ongoing debate, but focus is on multifactorial explanations

Scientific Critiques: What Does the Evidence Say?

• The idea of an “addictive personality” has been rigorously tested
• Overall finding: little scientific support for the concept

Lack of a Single Personality Profile

• No consistent set of traits explains all addictions
• People with addictions:
  • Come from diverse backgrounds
  • Have different personalities
• Challenges the idea of a universal addictive personality type

Methodological Issues

• Early studies often used cross-sectional designs
• Cannot determine:
  • Whether personality traits cause addiction
  • Or result from addiction
• Limits the strength and validity of conclusions

Risk Factors vs. Determinism

• Some personality traits may increase risk of addiction
• However:
  • Risk ≠ certainty
  • Not everyone with these traits becomes addicted
• Emphasises probability, not inevitability

False Assurance and Hopelessness

• Labelling someone as having an “addictive personality” can be harmful

Effects:

• Some people may feel immune (“that’s not me”)
• Others may feel powerless to change
• Oversimplification leads to misunderstanding risk

Popular Belief vs. Scientific Evidence

• Concept is popular in media and culture
• But not recognised scientifically as a valid diagnosis

Current understanding:

• Addiction is influenced by:
  • Genetic factors
  • Psychological factors
  • Social environment
  • Biological processes
• Addiction is complex and multifactorial

Key takeaway:

• The term “addictive personality” is misleading
• It oversimplifies a highly complex condition

Ethical & Practical Implications

Concept	Explanation	Key Consequences
Stigma and Stereotyping	Labelling reinforces negative stereotypes about people with addiction	Increased stigma, reduced help-seeking, potential discrimination from others (e.g. employers, healthcare providers)
False Security	Belief that only certain people are at risk	Others underestimate their own risk, delay recognising harmful behaviour, less likely to seek early help
Hopelessness and Fatalism	Individuals may believe their addiction is fixed or unavoidable	Reduced motivation to change, decreased likelihood of seeking treatment
Research and Treatment Implications	Focus shifts away from simplistic labels to complex, evidence-based understanding	Better prevention, improved interventions, more effective clinical practice

Personality Traits & Addiction

Key Models & Traits

Five Factor Model	A widely used model describing personality through five traits: openness, conscientiousness, extraversion, agreeableness, and neuroticism.
Neuroticism	A tendency toward emotional instability and negative emotions; higher levels are linked to greater addiction risk.
Conscientiousness	Reflects self-discipline and organisation; lower levels are associated with higher risk of addiction.
Impulsivity	A tendency to act without forethought; considered a key risk factor for both substance and behavioural addictions.
Agreeableness	Describes how cooperative and compassionate a person is; lower agreeableness is modestly linked to increased addiction risk.

Trait-by-Trait evidence for Addiction Risk

Trait	Relationship to Addiction	Explanation	Strength of Evidence
Neuroticism	Higher levels → higher risk	Individuals experience more negative emotions and may use substances/behaviours to cope	Strong, consistent
Conscientiousness	Lower levels → higher risk	Less self-discipline, organisation, and impulse control increases vulnerability	Strong
Impulsivity	Higher levels → higher risk	Acting without thinking increases likelihood of engaging in addictive behaviours	Very strong (key factor)
Agreeableness	Lower levels → slightly higher risk	Less empathy and cooperation may contribute to risk, but effect is smaller	Moderate to weak
Extraversion	Mixed findings	Some links found, but inconsistent across studies	Weak / inconsistent
Openness	Mixed findings	Minor or unclear associations with addiction risk	Weak / inconsistent

Personality Traits in Substance vs Behavioural Addictions

Category	Key Findings	Traits Involved	Important Notes
Substance Addictions	Associated with specific personality patterns	Higher neuroticism, lower conscientiousness, lower agreeableness	Impulsivity present but less prominent than in behavioural addictions
Behavioural Addictions	Similar trait patterns but with stronger impulsivity	Higher neuroticism, lower conscientiousness, high impulsivity	Impulsivity is often especially prominent
Overlap	Both share common risk traits	Neuroticism, impulsivity	Core shared vulnerability across addiction types
Differences	Strength of traits varies	Impulsivity stronger in behavioural addictions	Some traits (extraversion, openness) show inconsistent links
Substance Variation	Patterns differ depending on substance	Alcohol, nicotine, drugs vary in strength of associations	Not all substances show identical personality links
Socioeconomic & Environmental Factors	External factors influence addiction risk	Income, stress, peer groups, access to substances	Personality is only one part of the risk equation
Contextual Influences	Broader environment shapes outcomes	Culture, socioeconomic status	Affects both personality development and exposure to addiction

Strengths and Limitations of Personality–Addiction Research

Concept	Key Idea	Explanation	Key Implication
Effect Sizes	Differences are modest	Personality traits differ slightly between addicted and non-addicted individuals	Traits alone cannot reliably predict addiction
Causality	Direction is unclear	Many studies are cross-sectional, so cause vs. effect cannot be determined	Need longitudinal research to clarify relationships
Environmental & Cultural Factors	Context matters	Social environment, culture, and life circumstances strongly influence addiction risk	Personality must be considered alongside external factors
Prevention & Intervention	Multi-factor approach needed	Personality can inform strategies but should not be the sole focus	Most effective approaches are comprehensive and holistic

Bidirectional Links Between Addiction & Personality

Key concepts

Longitudinal Study	A research design that follows the same individuals over time to track changes, crucial for studying personality change after addiction.
Prospective Study	A study that measures variables before an outcome occurs, allowing researchers to observe how personality traits and addiction influence each other over time.
Bidirectionality	The concept that personality and addiction can mutually influence one another, rather than one simply causing the other.
Neuroadaptation	Brain changes that occur in response to repeated substance use, which can affect behaviour and personality traits.

Longitudinal and Prospective Studies

• Track individuals over time
• Compare behaviour before and after addiction develops
• Provide stronger evidence than cross-sectional studies

Key advantage:

• Help determine cause vs. effect (causality)
• Show whether addiction leads to personality changes

In contrast:

• Cross-sectional studies = snapshot at one point in time
• Cannot determine direction of relationship

Importance for Causality

• Longitudinal research allows researchers to:
  • Identify risk factors before addiction begins
  • Observe changes after addiction develops
• Provides stronger evidence for causal relationships

Example Study: Slutske et al. (2005)

• Longitudinal, population-based study
• Sample:
  • N = 939 participants
  • 18-year-olds (475 male, 464 female)
  • Follow-up after 3 years

Addictions studied:

• Gambling
• Nicotine
• Alcohol
• Cannabis

Key findings:

• Higher negative emotionality linked to addiction
• Lower constraint (self-control) linked to addiction
• These traits were associated with all types of addiction studied

What Does the Evidence Show? Personality Change After Addiction

• Research findings are mixed and complex
• Debate focuses on whether addiction:
  • Changes personality
  • Or personality remains largely stable

Evidence for Change

• Some studies show addiction can lead to:
  • Increased impulsivity
  • Increased aggression
  • Higher neuroticism
• Example: alcohol dependence → more impulsive, more conflict-prone

Quinn et al. (2011):

• Large prospective study (6,000+ students)
• Measured personality + alcohol use over time

Findings:

• Higher impulsivity & sensation seeking → predicted drinking (Time 1)
• Heavier drinking → later increases in these traits

→ Suggests addiction can change personality over time

Other perspectives:

• Early research: addiction causes “destruction of character”
• Later research: personality changes may be an effect of addiction, not a cause
• Likely due to brain changes (e.g. reward system alterations)

Evidence for Stability

• Some studies show personality is largely stable
• Core traits do not dramatically change for everyone

Östland et al. (2007):

• Longitudinal study (539 women, 5-year follow-up)

Findings:

• Personality mostly stable after alcohol dependence
• Minor changes:
  • Increased impulsivity
  • Increased verbal aggression

Recovery findings:

• Decreases in:
  • Irritability
  • Novelty seeking

→ Suggests some changes are reversible with recovery

Bidirectional Effects

• Strongest evidence supports a two-way relationship

Key idea:

• Personality traits → influence addiction risk
• Addiction → can then change those same traits
• Shows a dynamic interaction, not a one-way cause

Takeaway:

• Personality and addiction influence each other over time
• Relationship is complex, not fixed

How Can Addiction Change Personality?

Brain Changes

• Chronic substance use alters brain regions involved in:
  • Impulse control
  • Emotional regulation
  • Decision-making
• Especially affects the prefrontal cortex

Consequences:

• Reduced ability to manage emotions
• Difficulty resisting cravings
• Increased:
  • Impulsivity
  • Emotional instability

Dopamine and Reward Pathways

• Addiction disrupts dopamine systems (reward + motivation)
• Causes altered dopamine signalling

Effects:

• Changes in emotional stability and motivation
• Increases traits like:
  • Sensation seeking
  • Neuroticism

Important note:

• These changes can persist after substance use stops
• Brain can recover over time through neuroplasticity

Stress and Emotional Regulation

• Chronic substance use increases stress reactivity
• Impairs ability to regulate emotions

Consequences:

• Greater negative emotions
• Increased irritability
• Difficulty coping with everyday challenges
• Over time, contributes to changes in:
  • Neuroticism
  • Impulsivity

Recovery and Neuroplasticity

• The brain can adapt and recover (neuroplasticity)
• With sustained abstinence and support:
  • Some personality and brain changes can be reversed

Key takeaway:

• Recovery supports:
  • Positive personality change
  • Improved overall well-being

Flow Chart:

1. Substance Use / Addictive Behaviour

• Repeated engagement with substance or behaviour

↓

2. Brain Changes

• Affects prefrontal cortex (decision-making, impulse control)
• Weakens self-control
• Harder to regulate emotions

↓

3. Dopamine Disruption

• Reward system becomes dysregulated
• Dopamine surges reinforce behaviour
• Brain prioritises addiction over other goals

↓

4. Stress & Emotional Dysregulation

• Increased stress reactivity
• More negative emotions (irritability, anxiety)
• Poor coping with everyday challenges

↓

5. Personality Changes

• Increased:
  • Impulsivity
  • Neuroticism
  • Sensation seeking
• Decreased emotional stability

↓

6. Maintenance Cycle

• Personality changes make addiction more likely to continue
• Reinforces the cycle (feedback loop)

↓

7. Recovery & Neuroplasticity

• Brain can adapt and repair over time
• With abstinence + support:
  • Emotional regulation improves
  • Some personality traits return toward baseline