Personality and Health: Causal Models

Introduction

• This week's lectures focus on personality and its applications in various fields, specifically the relationship between personality and health.

• The lecture will cover four causal models that explain associations between personality and health.

Causal Models

• Four broad models will be considered:

  • Transactional Stress Moderation Model

  • Health Behavior Model

  • Structural Weakness Model

  • Illness Behavior Model

• The models are usually diagrams showing key variables and causal pathways, simplified for ease of discussion.

• The models are discussed separately but can operate synergistically.

Transactional Stress Moderation Model

• Builds on Lazarus and Volkmann's transactional stress model.

• Focuses on how personality moderates the stress transaction.

• Relevant personality constructs: Type A personality and hostility.

Lazarus and Volkmann's Transactional Stress Model Recap

• Objective qualities of the situation (Alpha Press): The actual environmental demands.

• Subjective appraisal (Beta Press): An individual's perception of the situation.

  • Situations can be perceived as non-stressful or stressful (involving environmental demand).

  • Stressful situations can be perceived as challenging or threatening.

• Threat Perception: Likely triggers Selye's biological stress reaction:

  • Activation of the autonomic and sympathetic nervous systems, and endocrine system.

  • Increased physiological arousal levels.

  • Chronically high arousal can lead to adverse health impacts.

• Coping Strategies:

  • Problem-focused coping is generally most effective.

  • Low self-efficacy can raise physiological arousal levels, increasing the potential for illness.

Personality Moderation

• Lazarus and Volkmann argue personality moderates stress-induced arousal and illness via three pathways:

  • Appraisal of the Situation:

    • Personality may alter the subjective appraisal of experiences.

    • Neurotic individuals are more likely to perceive situations as threatening and less manageable.

      • Triggers Selye's biological stress reaction -> raises arousal -> increases vulnerability to illness.

  • Coping Strategies:

    • Personality influences the availability, choice, and effectiveness of coping strategies and social resources.

    • Neuroticism is associated with ineffective coping strategies.

      • Leads to low self-efficacy -> raises arousal -> increases vulnerability to illness

  • Objective Features of the Situation:

    • People actively create or select situations based on their personality.

    • Neuroticism is associated with higher exposure to stressful situations and interpersonal conflict.

      • Triggers stress responses.

    • Pathways are bidirectional: the environment can shape personality.

      • Chronic exposure to adverse situations can lead to greater emotional instability or neuroticism.

Personality Constructs: Neuroticism

• Most closely associated with stress proneness.

• Self-report measures of neuroticism often include items that are proxy measures of stress (e.g., "Are you often under a lot of stress?").

• There is conceptual overlap between neuroticism and stress.

Personality Constructs: Hostility

• Grew out of earlier work on the Type A personality.

  • Developed by cardiologists Meyer Friedman and Ray Rosenman.

  • Observed that heart attack patients often had distinct personalities compared to other patients.

Type A Personality

• Defined as an action-emotion complex characterized by:

  • Aggressive involvement in a chronic, incessant struggle to achieve more in less time.

• Three narrow personality traits define the coronary-prone Type A personality:

  • Easily aroused hostility

  • Excessive competitive drive

  • Habitual sense of time urgency

• At a dimensional level, Type A personality is associated with a combination of high neuroticism and high extraversion (choleric temperament).

Western Collaborative Group Study

• Pioneered research on the Type A concept.

• Longitudinal prospective investigation of coronary heart disease incidence.

• 3,154 initially healthy men aged 39-59 were assessed between 1960-1961.

• Assessment was based on tape-recorded structured interviews.

• Participants were classified as either Type A or Type B (relaxed, easygoing).

• During an 8-9 year follow-up, 257 men were diagnosed with coronary heart disease.

• Incidence rate was over two times higher for Type A men than Type B men.

• Type A personality was a significant risk factor for coronary heart disease, comparable to traditional risk factors.

• The association was independent of other risk factors (age, weight, family history, smoking, cholesterol, blood pressure).

• Type A behavior was thought to cause more severe, frequent, or longer-lasting stress reactions.

  • Chronically high levels of stress-related physiological arousal increased the risk of coronary heart disease.

Shift in Research Focus

• Subsequent studies failed to consistently confirm the results from the Western Collaborative Group study.

• Research shifted to the hostility component of the Type A personality, considered the "toxic component".

• Competitiveness and time urgency did not independently predict coronary heart disease.

• Reexamination of the Western Collaborative Group study data found that only aggression/hostility independently predicted coronary heart disease.

• It was argued that it was acceptable to be competitive and driven as long as one did not become frustrated, aggressive, or hostile.

Barefoot et al. Study

• Examined the association between hostility and coronary heart disease.

• 255 male medical students completed the Cook Medley Hostility Index in 1955.

  • Derived from a subset of items from the Minnesota Multiphasic Personality Inventory.

• Incidence of coronary heart disease and all-cause mortality was monitored for 25 years.

• Participants who scored above the median on hostility (score of 14 or more) had five times the incidence of clinical coronary heart disease.

• Hostility scores also predicted all-cause mortality.

• The figure showed a marked decline in survival rate over 25 years for individuals high on hostility.

Meta-Analysis

• Numerous studies have since confirmed a significant but modest association between hostility and coronary heart disease.

• Meta-analysis of 45 studies found that self-reported hostility traits accounted for about 3.2% of the variance in coronary heart disease.

• A more recent meta-analysis focused exclusively on prospective studies suggests a somewhat weaker relationship.

• The weak association may be attributed to the health behaviors of hostile individuals, rather than the biological stress response.

  • Hostility has been shown to predict cardiovascular risk factors such as smoking and alcohol.

  • Individuals high on hostility are likely to smoke more, drink more, not engage in exercise, have excessive caloric intake, and be of low socioeconomic status.

Health Behavior Model

• Personality affects health by influencing engagement in health-damaging or health-enhancing behaviors.

• Poor health behaviors increase the risk of developing certain illnesses.

• Good health behaviors decrease the risk.

• Personality may affect health behaviors directly or indirectly (as a consequence of coping style).

Direct Model

• Personality may shape a person's belief system about the importance of healthy behaviors or the risks of negative health behaviors.

• Drivers convicted of speeding or reckless driving tend to have higher scores on psychoticism.

Indirect Model

• Health behaviors may be a result of how an individual copes with stress.

• Neurotic individuals are more likely to report using alcohol to cope with stress and less likely to use exercise.

• Poor health behaviors may be a maladaptive way of medicating stress.

Conscientiousness

• One of the most consistent personality predictors of health-related behaviors.

• Conscientiousness is defined in terms of:

  • Propensity to follow socially prescribed norms, impulse control, task and goal direction, planfulness, delayed gratification, following rules.

• Friedman et al.'s work with termites first established a robust relationship between conscientiousness and longevity.

Meta-Analysis (Bogg & Roberts)

• Examined the relationship between conscientiousness-related traits and leading health-related behaviors that contribute to mortality in the U.S.

• Health behaviors included:

  • Tobacco use, diet and activity patterns, excessive alcohol use, violence, risky sexual behavior, risky driving, suicide, and drug use.

• Strongest association was found between conscientiousness and drug use (r = -0.28).

  • Individuals low on conscientiousness are more likely to engage in drug use.

• Moderate correlations for excessive alcohol use, violence, and risky driving (around r = -0.25).

  • Individuals low on conscientiousness were more likely to use alcohol excessively, engage in violent activities, and engage in risky driving.

• Negative associations with tobacco use, risky sex, unhealthy eating, and suicide (smaller correlations).

• No relationship found between conscientiousness and activity (r = 0.05).

Neuroticism and Extraversion

• Also been found to predict health behaviors, but findings are inconsistent.

• Torgerson and Volrath argue that inconsistencies can be explained by considering neuroticism and extraversion in combination with conscientiousness.

• It's important to consider an individual's overall profile on the Big Five or Big Three.

Tobacco Use Example

• Individuals most likely to smoke are low in conscientiousness and either high in extraversion or high in neuroticism (or both).

• Individuals least likely to smoke have a combination of high conscientiousness and high introversion, irrespective of neuroticism.

Risky Driving Example

• A lack of conscientiousness together with high extraversion increases exposure to risky driving.

• High conscientiousness and high introversion is most protective.

Structural Weakness Model

• Associations between personality and health occur because a biological structure influences both vulnerability to illness and expression of a personality trait.

• A third variable (biological vulnerability) influences both health status and personality.

• In this model, personality isn't causing illness.

• The model is often used to explain associations between neuroticism and illness.

• Chronic autonomic nervous system activity may lead to both stress-related illness and higher levels of neuroticism.

Comparison to Transactional Stress Moderation Model

• Both models hold that individuals high on neuroticism are prone to stress.

• However, in the structural weakness model, neuroticism does not moderate cognitive appraisal and coping style to cause changes in autonomic activation.

• Rather, neuroticism is merely a marker for an underlying biological vulnerability.

Illness Behavior Model

• A model of illness behavior, not illness per se.

• Illness behavior includes reporting symptoms, seeing a physician, taking medication, etc.

• Illness behavior is a self-regulatory process crucial to effective illness management.

• The process involves:

  • Detecting a physical sensation.

  • Labeling it as an illness.

  • Taking appropriate action.

• The model holds that personality influences the degree to which a person perceives and labels bodily sensations as illness.

• The model was developed to highlight the dangers of relying on subjective health report symptoms to measure health status.

Neuroticism

• Particularly relevant in this context.

• Numerous studies implicate neuroticism as a predictor of various forms of ill health.

• However, there is growing concern that these findings simply reflect a tendency towards a complaint-prone personality (neurotic artifact).

• Neurotic individuals are more likely to complain about their health in the absence of hard evidence.

• The illness behavior of neurotic individuals creates a selection bias, influencing who seeks medical care and who receives a diagnosis.

RACE Study Example

• Naval personnel on ships reported major life events and then reported illness on board.

• Findings may be due to neurotic artifact (individuals high on neuroticism are more likely to report a higher incidence of major life events and report more illness symptoms).

Objective Health Endpoints

• Despite neurotic artifact, there is solid evidence from prospective studies to link neuroticism to hard objective health endpoints.

• Examples: diagnosed asthma, gastrointestinal disorders, and mortality from all causes.

British Nationwide Study Example

• Administered the ISINC personality inventory to 5,424 individuals.

• Mortality rate was assessed for the next 21 years.

• A one standard deviation increase in neuroticism was associated with a 12% increased risk of death from cardiovascular disease.

• Association remained significant after controlling for other factors (occupational social status, education, smoking, alcohol consumption, and physical activity).

Conclusions

• Transactional stress moderation and health behavior models assume that personality causes illness.

• Structural weakness and illness behavior models articulate pathways through which personality may appear to be associated with illness in the absence of a direct causal relationship.

• No consideration has been given to a causal pathway running from illness back to personality.

• Chronic illness may raise neuroticism levels due to greater difficulty in coping with day-to-day activities.

Longitudinal Perspective Studies

• Important to focus on, rather than cross-sectional studies.

• The temporal element ensures that the direction of causation is easier to infer.

• When personality is assessed at the outset of a longitudinal study, later illness cannot have influenced baseline personality scores.

Objective or Hard Signs of Physical Health

• Important to focus on.

• Examples: documented coronary heart disease or mortality from all causes.

• Studies that employ subjective self-reports of health status may be contaminated by neurotic artifact.

Disease-Prone Personality Profile

• The combination of low conscientiousness and high neuroticism seems to be a risk factor for a range of poor health outcomes by multiple causal pathways.

Personality and Cancer

• There is no evidence for a cancer-prone personality.

• The Big Five appear to be unrelated to the onset of and survival from cancer.

• There does, however, seem to be a predictive role for feelings of helplessness or hopelessness in cancer survival (not the onset of cancer).

The Transactional Stress Moderation Model, rooted in Lazarus and Volkmann's transactional stress model, posits that personality moderates the impact of stress on health through several key steps:

1. Objective Qualities of the Situation (Alpha Press): This refers to the actual environmental demands present in a given situation. It's the objective reality of the stressor.

2. Subjective Appraisal (Beta Press): This is the individual's perception and interpretation of the situation. The same situation can be appraised differently by different people.

   • Non-Stressful vs. Stressful: An individual assesses whether the situation poses a demand that could lead to stress.

   • Challenge vs. Threat: If deemed stressful, the individual further evaluates whether the situation is a challenge they can overcome or a threat that could harm them.

3. Threat Perception: If the situation is perceived as threatening, it triggers Selye's biological stress reaction.

   • Activation of Physiological Systems: This involves the activation of the autonomic and sympathetic nervous systems, as well as the endocrine system.

   • Increased Arousal: Physiological arousal levels increase.

   • Adverse Health Impacts: Chronically high arousal can lead to negative health outcomes.

4. Coping Strategies: Individuals employ coping strategies to manage the stressful situation.

   • Problem-Focused Coping: This involves directly addressing the problem causing the stress and is generally the most effective approach.

   • Self-Efficacy: Low self-efficacy (belief in one's ability to succeed) can raise physiological arousal levels, increasing the potential for illness.

5. Personality Moderation: Personality influences this entire stress transaction process through three pathways:

   • Appraisal of the Situation: Personality traits, such as neuroticism, can alter the subjective appraisal of experiences. Neurotic individuals are more likely to perceive situations as threatening and less manageable, which in turn triggers a biological stress reaction, raises arousal, and increases vulnerability to illness.

   • Coping Strategies: Personality affects the availability, choice, and effectiveness of coping strategies and social resources. For example, neuroticism is associated with ineffective coping strategies, leading to low self-efficacy, raised arousal, and increased vulnerability to illness.

   • Objective Features of the Situation: People actively create or select situations based on their personality. Neuroticism is associated with higher exposure to stressful situations and interpersonal conflict, which trigger stress responses. The environment can also shape personality; chronic exposure to adverse situations can lead to greater emotional instability or neuroticism.

In summary, the Transactional Stress Moderation Model highlights how personality influences the way individuals perceive, react to, and cope with stress, ultimately affecting their health. It considers the interplay between objective stressors, subjective appraisals, coping mechanisms, and the moderating role of personality traits like neuroticism and hostility.