Difficulty: Introductory to Intermediate | Prerequisites: Ch. 1–2 notes (biopsychosocial model, body systems basics).
These two chapters move from theory to action. Chapter 3 covers what health behaviours are, how prevention is structured (Caplan's model and the IOM model), what factors make behaviour change difficult, and the major models used to understand and promote change (Health Belief Model, Theory of Planned Behaviour, Transtheoretical Model, Motivational Interviewing, CBT, and more). Chapter 4 applies all of that to specific health-promoting behaviours: exercise, screenings, sun safety, diet, sleep, and vaccinations. You need Ch. 1–2's biopsychosocial framework and body systems knowledge to make sense of why these behaviours matter physiologically.
Health behaviours are the things people do (or fail to do) that affect their health, and health habits are the subset that become automatic, usually forming in childhood. Several models explain why people change or resist change, from the Health Belief Model (perceived threat and effectiveness) to the Transtheoretical Model (stages of change). Chapter 4 focuses on specific behaviours: exercise, cancer screenings, sun safety, diet, sleep, and HPV vaccination, along with the psychological concepts (cognitive dissonance, psychological reactance) that explain why people resist health messages.
Health behaviours
Behaviours people engage in to enhance or maintain health. In simple terms, things you do on purpose to stay well.
Health habits
Health behaviours that have become firmly established and automatic, usually developed in childhood. Think of brushing your teeth: you do it without deciding to.
Teachable moment
A time when the opportunity to modify a health practice is particularly high and success is more likely. Typically occurs when people are more trusting or open, such as during childhood, pregnancy, or after a new diagnosis.
Health Belief Model
A model stating that a person's likelihood of practising a health behaviour depends on whether they see the health threat as personally relevant and whether they believe the health practice will effectively reduce that threat. Does not account for self-efficacy.
Theory of Planned Behaviour
A model stating that health behaviours are a direct result of behavioural intentions, which are shaped by attitudes toward the action, subjective norms (what others think one should do), and perceived behavioural control.
Cognitive behavioural therapy (CBT)
The most effective cognitive-behavioural approach. Focuses on the target behaviour itself, the conditions that elicit and maintain it, and the factors that reinforce it. Uses self-monitoring, self-control, self-reinforcement, and behavioural assignments.
Self-Determination Theory
The idea that people are actively motivated to pursue their goals, with components related to competence and autonomous motivation. People are most motivated when they have free will to change.
Motivational Interviewing
A nonjudgemental, nonconfrontational, encouraging, and supportive clinical style that helps clients express positive or negative thoughts about a behaviour in an atmosphere free from negativity. Originally developed to treat addiction. No effort is made to dismantle denial or irrational beliefs.
Transtheoretical Model (Stages of Change)
A stage-based model analysing the processes people go through in changing behaviour: precontemplation, contemplation, preparation, action, and maintenance. Originally developed to treat addictive disorders.
Social engineering
Modifying the environment in ways that affect people's abilities to practise a particular health behaviour. Think of adding bike lanes to encourage cycling.
Cognitive dissonance
The discomfort that arises when a person's behaviours and attitudes do not match. People tend to resolve it by changing the attitude rather than the behaviour.
Psychological reactance
The tendency to reject or resist a message when too much fear is instilled, causing the person to ignore the warning and continue the behaviour.
DNA methylation
An epigenetic mechanism that helps explain ethnic and sex/gender differences in health. Considered a good explanation for health disparities, unlike telomere length (which is considered a weaker explanation).
Incidence
The number of new cases of a disease in a population over a given time period.
Prevalence
The total number of existing cases of a disease in a population at a given time.
Health behaviours are deliberate actions people take to enhance or maintain health. Health habits are the subset that become firmly established and automatic, usually developing in childhood. The distinction matters because habits are harder to change precisely because they are automatic.
Caplan's Model of Prevention – Primary, Secondary, Tertiary
Primary prevention: Targets the whole population regardless of health status. Goal is to reduce incidence (new cases). Examples: universal pre-K, Head Start.
Secondary prevention: Targets people showing early signs and symptoms. Goal is to reduce prevalence (total cases). Examples: identifying students showing early signs of distress.
Tertiary prevention: Treatment to decrease disability. Can target either prevalence or incidence. Examples: parenting interventions for families with preterm infants.
Institute of Medicine (IOM) Model – Universal, Selective, Indicated
Universal: Targets the whole population regardless of health status. Reduces incidence. Example: PAX Good Behavior Program.
Selective: Targets at-risk people. Reduces prevalence. Example: KidPact for children of incarcerated parents.
Indicated: Targets high-risk members or communities who do not yet have a diagnosis. Example: Project Towards No Drug Abuse, targeting high schoolers with identified substance use before it becomes abuse.
Model Overlap and Differences
Promotion can occur at any time in either model
Prevention can occur at any time in the IOM model, but is mainly in secondary for Caplan's model
Treatment is only in tertiary of Caplan's model
Prevention models are designed to build health behaviours. Even behaviours that are not directly related to health (e.g. social skills, coping strategies) can be related to health outcomes.
Five factors make behaviour change difficult:
Emotion: resistance to pressure, threats
Motivation: low perceived urgency
Social influence: peer norms, family expectations
Knowledge/cognition: not understanding the risk
Level of difficulty: how hard the change actually is
The time when the opportunity to modify a health practice is particularly high and success is more likely. This typically occurs when people are more trusting or receptive: childhood, pregnancy, or receiving a new diagnosis.
DNA methylation is considered a good explanation for health disparities
Telomere length is considered a weaker explanation
Must consider cultural norms and practices
SES is a social determinant of health
Biologic predispositions often mean genetic predispositions
Research increasingly examines epigenetic effects of oppression, trauma, and inequity
Health Belief Model
A person's likelihood of practising a health behaviour depends on two things: whether they see the threat as personally relevant, and whether they believe the health practice will be effective at reducing the threat. A key limitation is that the model leaves out self-efficacy.
Theory of Planned Behaviour
Health behaviours are a direct result of behavioural intentions. Those intentions are shaped by three components:
Attitudes toward the specific action
Subjective norms: what the person believes others think they should do, and their motivation to comply
Perceived behavioural control
Cognitive-Behavioural Approaches
Focus on the target behaviour itself, the conditions that trigger and maintain it, and the reinforcing factors. The most effective approach is CBT, which uses self-monitoring, self-control, self-reinforcement, and behavioural assignments.
Self-Determination Theory
People are actively motivated to pursue their goals. Change is most effective when people feel competent and autonomously motivated (having free will to change, rather than being coerced).
Modelling
The extent to which people perceive themselves as similar to others engaging in a particular behaviour. Seeing someone "like me" do something healthy makes it feel achievable.
Social Skills and Relaxation Training
Social skills training: helps people learn to relax and interact comfortably in social situations. Relevant because some poor health habits develop as a response to social anxiety.
Relaxation training: muscle relaxation and deep breathing to help control stress.
Stress is a primary factor targeted in both approaches.
Motivational Interviewing
A nonjudgemental, nonconfrontational, encouraging, and supportive style. The goal is to help the client express both positive and negative thoughts about a behaviour in an atmosphere free from negativity. Key features:
Originally developed to treat addiction
Client and counsellor talk equally
No effort is made to dismantle the denial or irrational beliefs that accompany the poor behaviour
Transtheoretical Model (Stages of Change)
Analyses the stages and processes people go through in changing behaviour. Originally developed to treat addictive disorders. Stage-based, with mini-interventions to move people from one stage to the next.
Precontemplation: No intention of changing. Usually not aware they have a problem, even though family may be.
Contemplation: Aware of the problem and thinking about it, but not committed to action.
Preparation: Intend to change but have not done so successfully. May be reducing the behaviour (e.g. smoking fewer cigarettes) but not fully committed to stopping.
Action: Actively modifying behaviour to overcome the problem. Requires commitment of time and energy. Involves stopping the behaviour and modifying lifestyle and environment.
Maintenance: Working to prevent relapse and consolidate gains. A person is in this stage once they have remained free of the addictive behaviour for more than 6 months.
Social Engineering
Modifies the environment in ways that affect people's abilities to practise a particular health behaviour. Examples: adding bike lanes, removing vending machines from schools, creating smoke-free zones.
Cognitive dissonance occurs when a person's behaviours and attitudes do not match. People tend to resolve it by changing their attitude (the easier route) rather than changing the behaviour.
Psychological reactance is what happens when too much fear is instilled: the person ignores the warning and continues the behaviour. Example: telling someone that smoking increases their risk of dying by 4%, but they dismiss it because their uncle smoked and lived to 80.
These behaviours address the major causes of illness and death in industrialised countries.
How many adults lack regular physical activity? About 50%.
Recommendations:
2.5–5 hours per week of moderate activity
1–2.5 hours per week of vigorous aerobic activity (high intensity, endurance activities)
Characteristics that support exercise – Personal:
High self-efficacy
Seeing yourself as athletic
Being extroverted
Self-esteem
Positive attitudes towards exercise
Families that exercise
Social support and encouragement
Personal enjoyment
Sense of health responsibility
Characteristics that support exercise – Environmental:
Convenient, accessible settings
Less crowded settings
Safe settings
More developed outdoor exercise space
Social support (partners, group exercise)
Exercise interventions that work:
Those that incorporate self-control and motivation
Helping people with implementation intentions (texting reminders can promote activity)
Matching interventions to the person's stage of readiness (Transtheoretical Model)
Factors that impact whether people get screened:
Self-efficacy
Perceived benefits
Physician recommendations
Social norms that support screening
Barriers such as SES and poor health
SES discussion: lack of ability to get to screening, lack of a safe place, lack of insurance
Biggest risk is UV exposure. Preventable measures include wearing a hat, applying sunscreen, and avoiding tanning.
Key takeaways from the research (Sander et al., 2020; Gloster and Neal, 2006):
Sunscreen reduces risk of both melanoma and nonmelanoma skin cancer
People with darker skin do still need sunscreen
Babies under 6 months should use physical protection rather than chemical sunscreen, because their skin is very thin
There is no strong evidence that sunscreen chemicals negatively affect endocrine or reproductive systems
Most people do not apply enough sunscreen and do not reapply often enough
Some chemical sunscreens have particles that persist in the body, though this finding comes from a small sample
An unhealthy diet is a risk factor for other diseases
Many people in the US lack the full nutrition recommended by the CDC
Food preferences form in childhood, not adolescence (though adolescence is when more autonomous food choices begin)
Key takeaways from the "Sleep Is Your Superpower" material:
Lack of sleep affects both male and female reproductive systems
Sleep is needed both before and after learning
Sleep deprivation prevents the hypothalamus from being properly active
NK (natural killer) cells decrease with less sleep
Sleep is not a bank: you cannot skip sleep one night and make up for it the next
Sleep tips:
Go to sleep and wake up at the same time every day (regularity)
Keep the room cold (about 65 degrees Fahrenheit / 18 degrees Celsius)
If you are awake for too long, leave the room and return when you feel tired
HPV vaccination is now routine for everyone by age 13, with availability up to age 45:
Routine from ages 11–12
Catch-up vaccine ages 13–26
Shared clinical decision-making ages 27–45
Students often confuse incidence and prevalence. Incidence counts new cases over a time period. Prevalence counts all existing cases at a point in time. Primary prevention targets incidence; secondary targets prevalence.
Students sometimes think the Health Belief Model and the Theory of Planned Behaviour are interchangeable. They are different: the Health Belief Model focuses on perceived threat and effectiveness; the Theory of Planned Behaviour focuses on intentions shaped by attitudes, subjective norms, and perceived control. The Health Belief Model also notably leaves out self-efficacy.
Students often assume the Transtheoretical Model is linear. People frequently cycle back through stages (e.g. relapsing from action back to contemplation).
Students sometimes think motivational interviewing involves challenging the client's denial. The opposite is true: no effort is made to dismantle denial or irrational beliefs.
Know the difference between Caplan's model (primary, secondary, tertiary) and the IOM model (universal, selective, indicated), including examples of each level.
Understand the distinction between incidence and prevalence and which prevention level targets which.
Be able to name and describe all five stages of the Transtheoretical Model with examples.
Know what makes the Health Belief Model different from the Theory of Planned Behaviour, and the key limitation of each.
Understand motivational interviewing's core principle: nonjudgemental, nonconfrontational, no effort to dismantle denial.
Know that CBT is identified as the most effective cognitive-behavioural approach.
Be able to explain cognitive dissonance and psychological reactance with examples.
Know the exercise recommendations (2.5–5 hours moderate or 1–2.5 hours vigorous per week) and that about 50% of adults lack regular physical activity.
Know the factors that impact colorectal cancer screening uptake, especially SES barriers.
Be able to list the sleep tips and explain why sleep is not a "bank."
Know the HPV vaccination schedule (routine 11–12, catch-up 13–26, shared decision-making 27–45).
Understand that DNA methylation is a good explanation for health disparities, while telomere length is not.
True or False: The Health Belief Model includes self-efficacy as a key component.
Fill in the blank: In the Transtheoretical Model, a person who has been free of addictive behaviour for more than 6 months is in the _______ stage.
True or False: In motivational interviewing, the counsellor actively works to dismantle the client's denial.
Fill in the blank: _______ prevention targets the whole population regardless of health status and aims to reduce incidence.
True or False: Psychological reactance means that instilling more fear always leads to better health behaviour change.
Answers: 1. False (it leaves out self-efficacy) 2. Maintenance 3. False (no effort is made to dismantle denial) 4. Primary (Caplan) or Universal (IOM) 5. False (too much fear can cause the person to ignore the message and continue the behaviour)
Q: What is the difference between a health behaviour and a health habit?
A: A health behaviour is any behaviour a person engages in to enhance or maintain health. A health habit is a health behaviour that has become firmly established and automatic, usually developed in childhood.
Q: Compare Caplan's primary prevention with the IOM's universal prevention. How are they similar and different?
A: Both target the whole population regardless of health status and aim to reduce incidence (new cases). They are largely equivalent at this level. The key difference is in how the rest of each model is structured: Caplan's secondary and tertiary levels differ from IOM's selective and indicated levels in terms of who they target and what they aim to reduce.
Q: A patient knows smoking is bad for them but continues to smoke. They resolve the tension by telling themselves "I only smoke a few a day, so it's fine." What concept does this illustrate?
A: Cognitive dissonance. Their behaviour (smoking) and attitude (knowing it is harmful) conflict, so they change their attitude to reduce the discomfort.
Q: Name the five stages of the Transtheoretical Model in order.
A: Precontemplation, contemplation, preparation, action, maintenance.
Q: What are the three components of behavioural intentions in the Theory of Planned Behaviour?
A: Attitudes toward the specific action, subjective norms regarding the action, and perceived behavioural control.
Q: A doctor tells a young patient that binge drinking increases liver disease risk by 40%. The patient dismisses the warning and drinks more that weekend. What concept explains this reaction?
A: Psychological reactance. Instilling too much fear can cause the person to ignore the message and continue or even increase the behaviour.
Q: What is a teachable moment? Give two examples.
A: A time when the opportunity to modify a health practice is particularly high and success is more likely. Examples include childhood (when habits are forming and trust is high), pregnancy (motivation to protect the baby), and receiving a new diagnosis (heightened awareness of health risks).
Q: Why is DNA methylation considered a better explanation for health disparities than telomere length?
A: DNA methylation captures the epigenetic effects of oppression, trauma, and inequity on gene expression, providing a mechanism for how social experiences become biological differences. Telomere length, while correlated with ageing and stress, is considered a weaker and less specific explanation for health disparities.
The behaviour change models in Chapter 3 apply directly to every specific health behaviour discussed in Chapter 4. For example, the Transtheoretical Model's stages of change map onto exercise interventions (matching the intervention to the person's stage of readiness). The social determinants of health from Chapter 2 reappear here as barriers to screenings, exercise access, and healthy diet. The stress response system from Chapter 2 (sympathetic nervous system, catecholamines, adrenal glands) connects to why relaxation training and social skills training are effective behavioural interventions. These chapters also set the stage for later material on stress and coping, where many of these models are applied to managing chronic illness.
Health behaviours, health habits, health promotion, prevention models, Caplan's model, primary prevention, secondary prevention, tertiary prevention, IOM model, universal prevention, selective prevention, indicated prevention, incidence vs. prevalence, Health Belief Model, Theory of Planned Behaviour, cognitive behavioural therapy, CBT, Self-Determination Theory, modelling, motivational interviewing, Transtheoretical Model, stages of change, precontemplation, contemplation, preparation, action, maintenance, social engineering, cognitive dissonance, psychological reactance, teachable moment, DNA methylation, telomere length, epigenetics, exercise recommendations, colorectal cancer screening, SES barriers, sun safety, UV exposure, sunscreen, HPV vaccination, healthy diet, sleep hygiene, NK cells, PSY 320, Michigan State University